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Yang F, Stahnke R, Lawal K, Mahnen C, Duffy P, Xu S, Durig T. Development of poly (lactic-co-glycolic acid) (PLGA) based implants using hot melt extrusion (HME) for sustained release of drugs: The impacts of PLGA's material characteristics. Int J Pharm 2024; 663:124556. [PMID: 39122196 DOI: 10.1016/j.ijpharm.2024.124556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 07/26/2024] [Accepted: 08/02/2024] [Indexed: 08/12/2024]
Abstract
Hot melt extrusion (HME) processed Poly (lactic-co-glycolic acid) (PLGA) implant is one of the commercialized drug delivery products, which has solid, well-designed shape and rigid structures that afford efficient locoregional drug delivery on the spot of interest for months. In general, there are a variety of material, processing, and physiological factors that impact the degradation rates of PLGA-based implants and concurrent drug release kinetics. The objective of this study was to investigate the impacts of PLGA's material characteristics on PLGA degradation and subsequent drug release behavior from the implants. Three model drugs (Dexamethasone, Carbamazepine, and Metformin hydrochloride) with different water solubility and property were formulated with different grades of PLGAs possessing distinct co-polymer ratios, molecular weights, end groups, and levels of residual monomer (high/ViatelTM and low/ ViatelTM Ultrapure). Physicochemical characterizations revealed that the plasticity of PLGA was inversely proportional to its molecular weight; moreover, the residual monomer could impose a plasticizing effect on PLGA, which increased its thermal plasticity and enhanced its thermal processability. Although the morphology and microstructure of the implants were affected by many factors, such as processing parameters, polymer and drug particle size and distribution, polymer properties and polymer-drug interactions, implants prepared with ViatelTM PLGA showed a smoother surface and a stronger PLGA-drug intimacy than the implants with ViatelTM Ultrapure PLGA, due to the higher plasticity of the ViatelTM PLGA. Subsequently, the implants with ViatelTM PLGA exhibited less burst release than implants with ViatelTM Ultrapure PLGA, however, their onset and progress of the lag and substantial release phases were shorter and faster than the ViatelTM Ultrapure PLGA-based implants, owing to the residual monomer accelerated the water diffusion and autocatalyzed PLGA hydrolysis. Even though the drug release profiles were also influenced by other factors, such as composition, drug properties and polymer-drug interaction, all three cases revealed that the residual monomer accelerated the swelling and degradation of PLGA and impaired the implant's integrity, which could negatively affect the subsequent drug release behavior and performance of the implants. These results provided insights to formulators on rational PLGA implant design and polymer selection.
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Affiliation(s)
| | - Ryan Stahnke
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Kamaru Lawal
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Cory Mahnen
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | | | - Shuyu Xu
- Ashland Specialty Ingredients, Wilmington, DE, USA
| | - Thomas Durig
- Ashland Specialty Ingredients, Wilmington, DE, USA
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2
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Won J, Kang J, Kang W. Comparative Ocular Pharmacokinetics of Dexamethasone Implants in Rabbits. J Ocul Pharmacol Ther 2024. [PMID: 39046957 DOI: 10.1089/jop.2024.0052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024] Open
Affiliation(s)
- Jihyun Won
- College of Pharmacy, Chung-Ang University, Seoul, South Korea
| | - Juhyung Kang
- College of Pharmacy, Chung-Ang University, Seoul, South Korea
| | - Wonku Kang
- College of Pharmacy, Chung-Ang University, Seoul, South Korea
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3
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Grossetete F, Garot C, Crouzet E, Delavenne X, Gain P, Barnouin L, Thuret G. In Vitro/Ex Vivo Release Study of a Ground Umbilical Cord Matrix Loaded with Dexamethasone. J Funct Biomater 2024; 15:157. [PMID: 38921531 PMCID: PMC11204836 DOI: 10.3390/jfb15060157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/30/2024] [Accepted: 06/02/2024] [Indexed: 06/27/2024] Open
Abstract
Eye drops containing steroids and antibiotics are widely used to treat a large range of ocular diseases of the ocular surface. They require frequent instillation or a high dosage, which can affect quality of life. We developed a biomaterial from human umbilical cord that can be loaded with drugs before being placed in the inferior conjunctival fornix. In the present work, this viro-inactivated, freeze-dried, and sterile foam was loaded with dexamethasone phosphate. We studied the release kinetic of 100 mg of biomaterial loaded with 100 µg of dexamethasone phosphate. Assays have shown that the product can be loaded with 100 µg of dexamethasone and allows a progressive release over time for at least 48 h. In addition, when compared with the instillation of the same dexamethasone quantity (100 µg), instilled regularly via eye-drop solution at 0.79 mg/mL, the drug penetration through corneal tissues was better with the dexamethasone-loaded biomaterial.
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Affiliation(s)
| | - Charlotte Garot
- TBF—Tissue Bank of France, 6 Rue d’Italie, 69780 Mions, France; (F.G.)
| | - Emmanuel Crouzet
- Laboratory Biology, Engineering and Imaging for Ophthalmology, BiiO, Faculty of Medicine, Health Innovation Campus, 10 Rue de la Marandière, 42270 Saint-Priest en Jarez, France
| | - Xavier Delavenne
- Pharmacology and Toxicology Unit, University Hospital of Saint Etienne, 42000 Saint-Etienne, France
| | - Philippe Gain
- Laboratory Biology, Engineering and Imaging for Ophthalmology, BiiO, Faculty of Medicine, Health Innovation Campus, 10 Rue de la Marandière, 42270 Saint-Priest en Jarez, France
- Ophthalmology Department, University Hospital of Saint Etienne, 42000 Saint-Etienne, France
| | - Laurence Barnouin
- TBF—Tissue Bank of France, 6 Rue d’Italie, 69780 Mions, France; (F.G.)
| | - Gilles Thuret
- Laboratory Biology, Engineering and Imaging for Ophthalmology, BiiO, Faculty of Medicine, Health Innovation Campus, 10 Rue de la Marandière, 42270 Saint-Priest en Jarez, France
- Ophthalmology Department, University Hospital of Saint Etienne, 42000 Saint-Etienne, France
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4
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Karimi M, Abrishami M, Farzadnia M, Kamali H, Malaekeh-Nikouei B. In-situ forming biodegradable implants for sustained Fluocinolone acetonide release to the posterior eye: In-vitro and in-vivo investigations in rabbits. Int J Pharm 2024; 654:123973. [PMID: 38458402 DOI: 10.1016/j.ijpharm.2024.123973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/02/2024] [Accepted: 03/03/2024] [Indexed: 03/10/2024]
Abstract
Delivering medication to the posterior segment of the eye presents a significant challenge. Intravitreal injection has emerged as the preferred method for drug delivery to this area. However, current injectable non-biodegradable implants for fluocinolone acetonide (FA) require surgical removal after prolonged drug release, potentially affecting patient compliance. This study aimed to develop an in-situ forming biodegradable implant (ISFBI) optimal formulation containing PLGA504H and PLGA756S (50:50 w/w%) with the additive NMP solvent. The goal was to achieve slow and controlled release of FA over a two-month period with lower burst release, following a single intravitreal injection. Through morphology, rheology, stability and in-vitro release evaluations, the optimal formulation demonstrated low viscosity (0.12-1.25 Pa. s) and sustained release of FA at a rate of 0.36 µg/day from the third day up to two months. Furthermore, histopathology and in-vivo studies were conducted after intravitreal injection of the optimal formulation in rabbits' eye. Pharmacokinetic analysis demonstrated mean residence time (MRT) of 20.02 ± 0.6 days, half-life (t1/2) of 18.80 ± 0.4 days, and clearance (Cl) of 0.29 ± 0.03 ml/h for FA in the vitreous humor, indicating sustained and slow absorption of FA by the targeted retinal tissue from vitrea over the two-month period and eliminating through the anterior section of the eye, as revealed by its presence in the aqueous humor. Additionally, FA exhibited no detection in the blood and no evidence of systemic side effects or damage on the retinal layer and other organs. Based on these findings, it can be concluded that in-situ forming injectable biodegradable PLGA implants can show promise as a long-acting and controlled-release system for intraocular drug delivery.
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Affiliation(s)
- Malihe Karimi
- Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mojtaba Abrishami
- Department of Ophthalmology, Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mehdi Farzadnia
- Department of Pathology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Kamali
- Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Bizhan Malaekeh-Nikouei
- Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
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5
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Costello MA, Liu J, Kuehster L, Wang Y, Qin B, Xu X, Li Q, Smith WC, Lynd NA, Zhang F. Role of PLGA Variability in Controlled Drug Release from Dexamethasone Intravitreal Implants. Mol Pharm 2023; 20:6330-6344. [PMID: 37955890 DOI: 10.1021/acs.molpharmaceut.3c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Long-acting injectable formulations based on poly(lactide-co-glycolide) (PLGA) have been commercialized for over 30 years in at least 20 FDA-approved products. These formulations offer several advantages, including reduced dosing frequency, improved patient compliance, and maintenance of therapeutic levels of drug. Despite extensive studies, the inherent complexity of the PLGA copolymer still poses significant challenges associated with the development of generic formulations having drug release profiles equivalent to those of the reference listed drugs. In addition, small changes to PLGA physicochemical properties or the drug product manufacturing process can have a major impact on the drug release profile of these long-acting formulations. This work seeks to better understand how variability in the physicochemical properties of similar PLGAs affects drug release from PLGA solid implants using Ozurdex (dexamethasone intravitreal implant) as the model system. Four 50:50, acid-terminated PLGAs of similar molecular weights were used to prepare four dexamethasone intravitreal implants structurally equivalent to Ozurdex. The PLGAs were extensively characterized by using a variety of analytical techniques prior to implant manufacture using a continuous, hot-melt extrusion process. In vitro release testing of the four structurally equivalent implants was performed in both normal saline and phosphate-buffered saline (PBS), yielding drastically different results between the two methods. In normal saline, no differences in the release profiles were observed. In PBS, the drug release profiles were sensitive to small changes in the residual monomer content, carboxylic acid end group content, and blockiness of the polymers. This finding further underscores the need for a physiologically relevant in vitro release testing method as part of a robust quality control strategy for PLGA-based solid implant formulations.
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Affiliation(s)
- Mark A Costello
- College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, University of Texas at Austin, Austin, Texas 78712, United States
| | - Joseph Liu
- College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, University of Texas at Austin, Austin, Texas 78712, United States
| | - Louise Kuehster
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Yan Wang
- Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Bin Qin
- Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Xiaoming Xu
- Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Qi Li
- Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - William C Smith
- Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Nathaniel A Lynd
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
| | - Feng Zhang
- College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, University of Texas at Austin, Austin, Texas 78712, United States
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6
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Costello MA, Liu J, Wang Y, Qin B, Xu X, Li Q, Smith WC, Lynd NA, Zhang F. Manufacturing dexamethasone intravitreal implants: Process control and critical quality attributes. Int J Pharm 2023; 647:123515. [PMID: 37844672 DOI: 10.1016/j.ijpharm.2023.123515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/20/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Over 20 long-acting injectable formulations based on poly(lactide-co-glycolide) (PLGA) have been approved by the FDA to date. PLGA is a biodegradable polymer that can extend drug release from these dosage forms for up to six months after administration. Despite the commercial success of several of these formulations, there are still a limited number of products that utilize PLGA, and there are currently no generic counterparts of these products on the market. Significant technical challenges are associated with preparation of chemically and structurally equivalent formulations that yield an equivalent drug release profile to the reference listed drug (RLD) both in vitro and in vivo. In this work, Ozurdex (dexamethasone intravitreal implant) was used as a model system to explore how the manufacturing process of PLGA-based solid implants impacts the quality and performance of the dosage form. Control of implant structural characteristics, including diameter, internal porosity, and surface roughness, was required to maintain accurate unit dose potency. Implants were prepared by a continuous hot-melt extrusion process that was thoroughly characterized to show the importance of precise feeding control to meet dimensional specifications. Five extruder die designs were evaluated using the same hot-melt extrusion process to produce five structurally-distinct implants. The structural differences did not alter the in vitro drug release profile when tested in both normal saline and phosphate-buffered saline (pH 7.4); however, implant porosity was shown to impact the mechanical strength of the implants. This work seeks to provide insight into the manufacturing process of PLGA-based solid implants to support development of future novel and generic drug products.
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Affiliation(s)
- Mark A Costello
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Joseph Liu
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Yan Wang
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Bin Qin
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Xiaoming Xu
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Qi Li
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - William C Smith
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Nathaniel A Lynd
- University of Texas at Austin, McKetta Department of Chemical Engineering and Texas Materials Institute, Austin, TX, USA
| | - Feng Zhang
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA.
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7
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Bendicho-Lavilla C, Seoane-Viaño I, Santos-Rosales V, Díaz-Tomé V, Carracedo-Pérez M, Luzardo-Álvarez AM, García-González CA, Otero-Espinar FJ. Intravitreal implants manufactured by supercritical foaming for treating retinal diseases. J Control Release 2023; 362:342-355. [PMID: 37633363 DOI: 10.1016/j.jconrel.2023.08.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Chronic retinal diseases, such as age-related macular degeneration (AMD), are a major cause of global visual impairment. However, current treatment methods involving repetitive intravitreal injections pose financial and health burdens for patients. The development of controlled drug release systems, particularly for biological drugs, is still an unmet need in prolonging drug release within the vitreous chamber. To address this, green supercritical carbon dioxide (scCO2) foaming technology was employed to manufacture porous poly(lactic-co-glycolic acid) (PLGA)-based intravitreal implants loaded with dexamethasone. The desired implant dimensions were achieved through 3D printing of customised moulds. By varying the depressurisation rates during the foaming process, implants with different porosities and dexamethasone release rates were successfully obtained. These implants demonstrated controlled drug release for up to four months, surpassing the performance of previously developed implants. In view of the positive results obtained, a pilot study was conducted using the monoclonal antibody bevacizumab to explore the feasibility of this technology for preparing intraocular implants loaded with biologic drug molecules. Overall, this study presents a greener and more sustainable alternative to conventional implant manufacturing techniques, particularly suited for drugs that are susceptible to degradation under harsh conditions.
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Affiliation(s)
- Carlos Bendicho-Lavilla
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, and Materials Institute iMATUS, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain; Paraquasil Group (GI-2109), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| | - Iria Seoane-Viaño
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, and Materials Institute iMATUS, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain; Paraquasil Group (GI-2109), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain; Department of Pharmaceutics, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Víctor Santos-Rosales
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+D Farma (GI-1645), Facultad de Farmacia, Materials Institute iMATUS and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Victoria Díaz-Tomé
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, and Materials Institute iMATUS, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain; Clinical Pharmacology Group, Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| | - María Carracedo-Pérez
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+D Farma (GI-1645), Facultad de Farmacia, Materials Institute iMATUS and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Asteria M Luzardo-Álvarez
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, and Materials Institute iMATUS, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain; Paraquasil Group (GI-2109), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| | - Carlos A García-González
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, I+D Farma (GI-1645), Facultad de Farmacia, Materials Institute iMATUS and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, and Materials Institute iMATUS, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain; Paraquasil Group (GI-2109), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain.
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8
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Costello MA, Liu J, Chen B, Wang Y, Qin B, Xu X, Li Q, Lynd NA, Zhang F. Drug release mechanisms of high-drug-load, melt-extruded dexamethasone intravitreal implants. Eur J Pharm Biopharm 2023; 187:46-56. [PMID: 37037387 DOI: 10.1016/j.ejpb.2023.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/27/2023] [Accepted: 04/04/2023] [Indexed: 04/12/2023]
Abstract
Ozurdex is an FDA-approved sustained-release, biodegradable implant formulated to deliver the corticosteroid dexamethasone to the posterior segment of the eye for up to 6 months. Hot-melt extrusion is used to prepare the 0.46 mm × 6 mm, rod-shaped implant by embedding the drug in a matrix of poly(lactic-co-glycolic acid) (PLGA) in a 60:40 drug:polymer ratio by weight. In our previous work, the Ozurdex implant was carefully studied and reverse engineered to produce a compositionally and structurally equivalent implant for further analysis. In this work, the reverse-engineered implant is thoroughly characterized throughout the in vitro dissolution process to elucidate the mechanisms of controlled drug release. The implant exhibits a triphasic release profile in 37 °C normal saline with a small burst release (1-2 %), a one-week lag phase with limited release (less than10 %), and a final phase where the remainder of the dose is released over 3-4 weeks. The limited intermolecular interaction between dexamethasone and PLGA renders the breakdown of the polymer the dominating mechanism of controlled release. A close relationship between drug release and total implant mass loss was observed. Unique chemical and structural differences were seen between the core of the implant and the implant surface driven by diffusional limitations, autocatalytic hydrolysis, and osmotic effects.
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Affiliation(s)
- Mark A Costello
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Joseph Liu
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Beibei Chen
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Yan Wang
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Bin Qin
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Xiaoming Xu
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Qi Li
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Nathaniel A Lynd
- University of Texas at Austin, McKetta Department of Chemical Engineering and Texas Materials Institute, Austin, TX, USA
| | - Feng Zhang
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA.
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9
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Costello MA, Liu J, Wang Y, Qin B, Xu X, Li Q, Lynd NA, Zhang F. Reverse engineering the Ozurdex dexamethasone intravitreal implant. Int J Pharm 2023; 634:122625. [PMID: 36690129 DOI: 10.1016/j.ijpharm.2023.122625] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/09/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Ozurdex is a biodegradable implant formulated for sustained-release delivery of the corticosteroid dexamethasone to the posterior segment of the eye. The small, rod-shaped implant is administered directly to the vitreous using a dedicated applicator, and releases drug for up to 6 months after administration. Sustained release is achieved by embedding dexamethasone in a matrix of 50:50 poly(lactic-co-glycolic acid) (PLGA). In this work, the Ozurdex implant was thoroughly characterized to enable the reverse engineering of a compositionally and structurally equivalent implant. Advanced imaging techniques such as scanning electron microscopy (SEM) and microcomputed tomography (microCT) revealed that the Ozurdex implant exhibits an irregular surface and an internal porosity of 6% due to a large number of discrete voids approximately 3 μm in diameter. Thermal and spectroscopic analyses showed limited interaction between the drug and the polymer, resulting in a two-phase system of dexamethasone crystals embedded within a PLGA matrix. Reverse-engineered implants with properties similar to Ozurdex were prepared using a two-step hot-melt extrusion process. The reverse-engineered implants exhibited a triphasic drug release profile similar to Ozurdex. This work seeks to provide insight into the manufacturing process and characterization of PLGA-based solid implants to support future generic product development.
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Affiliation(s)
- Mark A Costello
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Joseph Liu
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA
| | - Yan Wang
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Bin Qin
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Xiaoming Xu
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Quality, Office of Testing and Research, Silver Spring, MD, USA
| | - Qi Li
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Generic Drugs, Office of Research and Standards, Silver Spring, MD, USA
| | - Nathaniel A Lynd
- University of Texas at Austin, McKetta Department of Chemical Engineering and Texas Materials Institute, Austin, TX, USA
| | - Feng Zhang
- University of Texas at Austin, College of Pharmacy, Department of Molecular Pharmaceutics and Drug Delivery, Austin, TX, USA.
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10
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Gautam M, Gupta R, Singh P, Verma V, Verma S, Mittal P, Karkhur S, Sampath A, Mohan RR, Sharma B. Intracameral Drug Delivery: A Review of Agents, Indications, and Outcomes. J Ocul Pharmacol Ther 2023; 39:102-116. [PMID: 36757304 DOI: 10.1089/jop.2022.0144] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
An intracameral (IC) injection directly delivers the drug into the anterior chamber of the eye. This targeted drug delivery technique overcomes the ocular barriers and offers a high therapeutic concentration of medication at the desired site and consequently better clinical outcomes. IC drug delivery is a safe and effective modality with many advantages over topical delivery. These include excellent bioavailability, reduced systemic risk, and minimal ocular toxicity. Agents delivered via IC injection have shown promising results against infection, inflammation, ocular hypertension, and neovascularization. Current literature shows that IC antibiotics, including cefuroxime, vancomycin, and moxifloxacin, are routinely used for prophylaxis of endophthalmitis. Other drugs available for IC use are steroids, anesthetics, mydriatics, miotics, antivascular endothelial growth factor, antiglaucoma, and alkylating agents. Introduction of sustained-release devices containing dexamethasone or Bimatoprost in anterior chamber via IC route has the potential in treating ocular inflammation and raised intraocular pressure. The complications such as hemorrhagic occlusive retinal vasculitis and toxic anterior segment syndrome have been documented with IC prophylaxis but are rare. In this review, we provide an overview of available IC drugs, their pharmacokinetics, the spectrum of activity, dosage and preparation, prophylactic and therapeutic usage, clinical efficacy, and safety profiles.
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Affiliation(s)
- Megha Gautam
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Rituka Gupta
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Priti Singh
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Vidhya Verma
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Sunil Verma
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Parul Mittal
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Samendra Karkhur
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Ananyan Sampath
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
| | - Rajiv R Mohan
- Department of Ophthalmology and Molecular Medicine, University of Missouri, Columbia, Missouri, USA
| | - Bhavana Sharma
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, India
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11
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Saraf I, Kushwah V, Alva C, Koutsamanis I, Rattenberger J, Schroettner H, Mayrhofer C, Modhave D, Braun M, Werner B, Zangger K, Paudel A. Influence of PLGA End Groups on the Release Profile of Dexamethasone from Ocular Implants. Mol Pharm 2023; 20:1307-1322. [PMID: 36680524 DOI: 10.1021/acs.molpharmaceut.2c00945] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present study deals with the development of dexamethasone (DM)-loaded implants using ester end-capped Resomer RG 502 poly(lactic acid-co-glycolic acid) (PLGA) (502), acid end-capped Resomer RG 502H PLGA (502H), and a 502H:502 mixture (3:1) via hot melt extrusion (HME). The prepared intravitreal implants (20 and 40% DM loaded in each PLGA) were thoroughly investigated to determine the effect of different end-capped PLGA and drug loading on the long-term release profile of DM. The implants were characterized for solid-state active pharmaceutical ingredient (APIs) using DSC and SWAXS, water uptake during stability study, the crystal size of API in the implant matrix using hot-stage polarized light microscopy, and in vitro release profile. The kinetics of PLGA release was thoroughly investigated using quantitative 1H NMR spectroscopy. The polymorph of DM crystal was found to remain unchanged after the extrusion and stability study. However, around 3 times reduction in API particle size was observed after the HME process. The morphology and content uniformity of the RT-stored samples were found to be comparable to the initial implant samples. Interestingly, the samples (mainly 502H) stored at 40 °C and 75% RH for 30 d demonstrated marked deformation and a change in content uniformity. The rate of DM release was higher in the case of 502H samples with a higher drug loading (40% w/w). Furthermore, a simple digital in vitro DM release profile derived for the formulation containing a 3:1 ratio of 502H and 502 was comparable with the experimental release profile of the respective polymer mixture formulation. The temporal development of pores and/or voids in the course of drug dissolution, evaluated using μCT, was found to be a precursor for the PLGA release. Overall, the release profile of DM was found to be dependent on the PLGA type (independent of subtle changes in the formulation mass and diameter). However, the extent of release was found to be dependent on DM loading. Thus, the present investigation led to a thorough understanding of the physicochemical properties of different end-capped PLGAs and the underlying formulation microstructure on the release profile of a crystalline water-insoluble drug, DM, from the PLGA-based implant.
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Affiliation(s)
- Isha Saraf
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Varun Kushwah
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Carolina Alva
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Ioannis Koutsamanis
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | | | - Hartmuth Schroettner
- Graz Centre for Electron Microscopy (ZFE), Steyrergasse 17, Graz8010, Austria.,Institute of Electron Microscopy and Nanoanalysis (FELMI), NAWI Graz, Graz University of Technology, Steyrergasse 17, Graz8010, Austria
| | - Claudia Mayrhofer
- Graz Centre for Electron Microscopy (ZFE), Steyrergasse 17, Graz8010, Austria
| | - Dattatray Modhave
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria
| | - Michael Braun
- Pharmaceutical Development, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach88397, Germany
| | - Bernd Werner
- Institute of Chemistry, University of Graz, Heinrichstr. 28, Graz8010, Austria
| | - Klaus Zangger
- Institute of Chemistry, University of Graz, Heinrichstr. 28, Graz8010, Austria
| | - Amrit Paudel
- Research Centre for Pharmaceutical Engineering, Inffeldgasse 13/2, Graz8010, Austria.,Institute for Process and Particle Engineering, Graz University of Technology, Inffeldgasse 13/3, Graz8010, Austria
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12
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Zheng A, Waterkotte T, Debele T, Dion G, Park Y. Biodegradable dexamethasone polymer capsule for long-term release. KOREAN J CHEM ENG 2023. [DOI: 10.1007/s11814-022-1358-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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13
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Bahuon F, Darcos V, Patel S, Marin Z, Coudane J, Schwach G, Nottelet B. Polyester-Polydopamine Copolymers for Intravitreal Drug Delivery: Role of Polydopamine Drug-Binding Properties in Extending Drug Release. Biomacromolecules 2022; 23:4388-4400. [PMID: 36170117 DOI: 10.1021/acs.biomac.2c00843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This work reports on a novel polyester copolymer containing poly(dopamine), a synthetic analogue of natural melanin, evaluated in a sustained-release drug delivery system for ocular intravitreal administration of drugs. More specifically, a graft copolymer of poly(ε-caprolactone)-graft-poly(dopamine) (PCL-g-PDA) has been synthesized and was shown to further extend the drug release benefits of state-of-the-art biodegradable intravitreal implants composed of poly(lactide) and poly(lactide-co-glycolide). The innovative biomaterial combines the documented drug-binding properties of melanin naturally present in the eye, with the established ocular tolerability and biodegradation of polyester implants. The PCL-g-PDA copolymer was obtained by a two-step modification of PCL with a final PDA content of around 2-3 wt % and was fully characterized by size exclusion chromatography, NMR, and diffusion ordered NMR spectroscopy. The thermoplastic nature of PCL-g-PDA allowed its simple processing by hot-melt compression molding to prepare small implants. The properties of unmodified PCL and PCL-g-PDA implants were studied and compared in terms of thermal properties (differential scanning calorimetry), thermal stability (thermogravimetry analysis), degradability, and in vitro cytotoxicity. PCL and PCL-g-PDA implants exhibited similar degradation properties in vitro and were both stable under physiological conditions over 110 days. Likewise, both materials were non-cytotoxic toward L929 and ARPE-19 cells. The drug loading and in vitro release properties of the new materials were investigated with dexamethasone (DEX) and ciprofloxacin hydrochloride (CIP) as representative drugs featuring low and high melanin-binding affinities, respectively. In comparison to unmodified PCL, PCL-g-PDA implants showed a significant extension of drug release, most likely because of specific drug-catechol interaction with the PDA moieties of the copolymer. The present study confirms the advantages of designing PDA-containing polyesters as a class of biodegradable and biocompatible thermoplastics that can modulate and remarkably extend the drug release kinetics thanks to their unique drug-binding properties, especially, but not limited to, for ocular applications.
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Affiliation(s)
- Floriane Bahuon
- IBMM (UMR5247), Univ Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Vincent Darcos
- IBMM (UMR5247), Univ Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Sulabh Patel
- Pharmaceutical Development, PTD Biologics Europe, F.Hoffmann-La Roche Ltd, Basel 4070, Switzerland
| | - Zana Marin
- Pharmaceutical Development, PTD Biologics Europe, F.Hoffmann-La Roche Ltd, Basel 4070, Switzerland
| | - Jean Coudane
- IBMM (UMR5247), Univ Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Grégoire Schwach
- Pharmaceutical Development, PTD Biologics Europe, F.Hoffmann-La Roche Ltd, Basel 4070, Switzerland
| | - Benjamin Nottelet
- IBMM (UMR5247), Univ Montpellier, CNRS, ENSCM, Montpellier 34095, France
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14
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Plontke SK, Liebau A, Lehner E, Bethmann D, Mäder K, Rahne T. Safety and audiological outcome in a case series of tertiary therapy of sudden hearing loss with a biodegradable drug delivery implant for controlled release of dexamethasone to the inner ear. Front Neurosci 2022; 16:892777. [PMID: 36203796 PMCID: PMC9530574 DOI: 10.3389/fnins.2022.892777] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/16/2022] [Indexed: 11/21/2022] Open
Abstract
Background Intratympanic injections of glucocorticoids have become increasingly common in the treatment of idiopathic sudden sensorineural hearing loss (ISSHL). However, due to their fast elimination, sustained applications have been suggested for local drug delivery to the inner ear. Materials and methods The study is based on a retrospective chart review of patients treated for ISSHL at a single tertiary (university) referral center. We included patients who were treated with a solid, biodegradable, poly(D,L-lactic-co-glycolic acid) (PLGA)-based drug delivery system providing sustained delivery of dexamethasone extracochlear into the round window niche (n = 15) or intracochlear into scala tympani (n = 2) for tertiary therapy of ISSHL in patients without serviceable hearing after primary systemic and secondary intratympanic glucocorticoid therapy. We evaluated the feasibility and safety through clinical evaluation, histological examination, and functional tests [pure-tone threshold (PTA), word recognition scores (WRS)]. Results With adequate surgical preparation of the round window niche, implantation was feasible in all patients. Histologic examination of the material in the round window niche showed signs of resorption without relevant inflammation or foreign body reaction to the implant. In patients where the basal part of scala tympani was assessable during later cochlear implantation, no pathological findings were found. In the patients with extracochlear application, average preoperative PTA was 84.7 dB HL (SD: 20.0) and 76.7 dB HL (SD: 16.7) at follow-up (p = 0.08). The preoperative average maximum WRS was 14.6% (SD: 17.9) and 39.3% (SD: 30.7) at follow-up (p = 0.11). Six patients (40%), however, reached serviceable hearing. The two patients with intracochlear application did not improve. Conclusion The extracochlear application of the controlled release system in the round window niche and – based on limited observations - intracochlear implantation into scala tympani appears feasible and safe. Due to the uncontrolled study design, conclusions about the efficacy of the treatment are limited. These observations, however, may encourage the initiation of prospective controlled studies using biodegradable controlled release implants as drug delivery systems for the treatment of inner ear diseases.
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Affiliation(s)
- Stefan K. Plontke
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
- *Correspondence: Stefan K. Plontke,
| | - Arne Liebau
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Eric Lehner
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Daniel Bethmann
- Institute of Pathology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Torsten Rahne
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
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15
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O'Brien Laramy MN, Nagapudi K. Long-acting ocular drug delivery technologies with clinical precedent. Expert Opin Drug Deliv 2022; 19:1285-1301. [PMID: 35912841 DOI: 10.1080/17425247.2022.2108397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Ocular long-acting injectables and implants (LAIIs) deliver drug at a controlled release rate over weeks to years. A reduced dose frequency eases the treatment burden on patients, minimizes the potential for treatment-related adverse effects, and improves treatment adherence and persistence. AREAS COVERED This review provides a comprehensive landscape of ocular LAII drug delivery technologies with clinical precedent, including eight commercial products and 27 clinical programs. Analysis of this landscape, and the specific technologies with the greatest precedent, provides instructive lessons for researchers interested in this space and insights into the direction of the field. EXPERT OPINION Further technological advancement is required to create biodegradable LAIIs with extended release durations and LAIIs that are compatible with a broader array of therapeutic modalities. In the future, ocular LAII innovations can be applied to diseases with limited treatment options, prophylactic treatment at earlier stages of disease, and cost-effective treatment of ocular diseases in global health settings.
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Affiliation(s)
- Matthew N O'Brien Laramy
- Small Molecule Pharmaceutical Sciences, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Karthik Nagapudi
- Small Molecule Pharmaceutical Sciences, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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16
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Lehner E, Menzel M, Gündel D, Plontke SK, Mäder K, Klehm J, Kielstein H, Liebau A. Microimaging of a novel intracochlear drug delivery device in combination with cochlear implants in the human inner ear. Drug Deliv Transl Res 2022; 12:257-266. [PMID: 33543398 PMCID: PMC8677643 DOI: 10.1007/s13346-021-00914-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2021] [Indexed: 12/17/2022]
Abstract
The effective delivery of drugs to the inner ear is still an unmet medical need. Local controlled drug delivery to this sensory organ is challenging due to its location in the petrous bone, small volume, tight barriers, and high vulnerability. Local intracochlear delivery of drugs would overcome the limitations of intratympanic (extracochlear) and systemic drug application. The requirements for such a delivery system include small size, appropriate flexibility, and biodegradability. We have developed biodegradable PLGA-based implants for controlled intracochlear drug release that can also be used in combination with cochlear implants (CIs), which are implantable neurosensory prosthesis for hearing rehabilitation. The drug carrier system was tested for implantation in the human inner ear in 11 human temporal bones. In five of the temporal bones, CI arrays from different manufacturers were implanted before insertion of the biodegradable PLGA implants. The drug carrier system and CI arrays were implanted into the scala tympani through the round window. Implanted temporal bones were evaluated by ultra-high-resolution computed tomography (µ-CT) to illustrate the position of implanted electrode carriers and the drug carrier system. The µ-CT measurements revealed the feasibility of implanting the PLGA implants into the scala tympani of the human inner ear and co-administration of the biodegradable PLGA implant with a CI array.
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Affiliation(s)
- Eric Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Matthias Menzel
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany
| | - Daniel Gündel
- Department of Nuclear Medicine, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Jessica Klehm
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany
| | - Heike Kielstein
- Institute of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Arne Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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17
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Kicková E, Sadeghi A, Puranen J, Tavakoli S, Sen M, Ranta VP, Arango-Gonzalez B, Bolz S, Ueffing M, Salmaso S, Caliceti P, Toropainen E, Ruponen M, Urtti A. Pharmacokinetics of Pullulan-Dexamethasone Conjugates in Retinal Drug Delivery. Pharmaceutics 2021; 14:pharmaceutics14010012. [PMID: 35056906 PMCID: PMC8779473 DOI: 10.3390/pharmaceutics14010012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/11/2021] [Accepted: 12/17/2021] [Indexed: 12/11/2022] Open
Abstract
The treatment of retinal diseases by intravitreal injections requires frequent administration unless drug delivery systems with long retention and controlled release are used. In this work, we focused on pullulan (≈67 kDa) conjugates of dexamethasone as therapeutic systems for intravitreal administration. The pullulan-dexamethasone conjugates self-assemble into negatively charged nanoparticles (average size 326 ± 29 nm). Intravitreal injections of pullulan and pullulan-dexamethasone were safe in mouse, rat and rabbit eyes. Fluorescently labeled pullulan particles showed prolonged retention in the vitreous and they were almost completely eliminated via aqueous humor outflow. Pullulan conjugates also distributed to the retina via Müller glial cells when tested in ex vivo retina explants and in vivo. Pharmacokinetic simulations showed that pullulan-dexamethasone conjugates may release free and active dexamethasone in the vitreous humor for over 16 days, even though a large fraction of dexamethasone may be eliminated from the eye as bound pullulan-dexamethasone. We conclude that pullulan based drug conjugates are promising intravitreal drug delivery systems as they may reduce injection frequency and deliver drugs into the retinal cells.
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Affiliation(s)
- Eva Kicková
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, 35131 Padova, Italy; (E.K.); (S.S.); (P.C.)
| | - Amir Sadeghi
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
| | - Jooseppi Puranen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
| | - Shirin Tavakoli
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, 00710 Helsinki, Finland;
| | - Merve Sen
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Str. 7, D-72076 Tübingen, Germany; (M.S.); (B.A.-G.); (S.B.); (M.U.)
| | - Veli-Pekka Ranta
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
| | - Blanca Arango-Gonzalez
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Str. 7, D-72076 Tübingen, Germany; (M.S.); (B.A.-G.); (S.B.); (M.U.)
| | - Sylvia Bolz
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Str. 7, D-72076 Tübingen, Germany; (M.S.); (B.A.-G.); (S.B.); (M.U.)
| | - Marius Ueffing
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Elfriede-Aulhorn-Str. 7, D-72076 Tübingen, Germany; (M.S.); (B.A.-G.); (S.B.); (M.U.)
| | - Stefano Salmaso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, 35131 Padova, Italy; (E.K.); (S.S.); (P.C.)
| | - Paolo Caliceti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, 35131 Padova, Italy; (E.K.); (S.S.); (P.C.)
| | - Elisa Toropainen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
| | - Marika Ruponen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1C, 70211 Kuopio, Finland; (A.S.); (J.P.); (V.-P.R.); (E.T.); (M.R.)
- Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, 00710 Helsinki, Finland;
- Institute of Chemistry, St. Petersburg State University, Petergof, Universitetskii pr. 26, 198504 St. Petersburg, Russia
- Correspondence:
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18
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Battiston K, Parrag I, Statham M, Louka D, Fischer H, Mackey G, Daley A, Gu F, Baldwin E, Yang B, Muirhead B, Hicks EA, Sheardown H, Kalachev L, Crean C, Edelman J, Santerre JP, Naimark W. Polymer-free corticosteroid dimer implants for controlled and sustained drug delivery. Nat Commun 2021; 12:2875. [PMID: 34001908 PMCID: PMC8129133 DOI: 10.1038/s41467-021-23232-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/08/2021] [Indexed: 12/30/2022] Open
Abstract
Polymeric drug carriers are widely used for providing temporal and/or spatial control of drug delivery, with corticosteroids being one class of drugs that have benefitted from their use for the treatment of inflammatory-mediated conditions. However, these polymer-based systems often have limited drug-loading capacity, suboptimal release kinetics, and/or promote adverse inflammatory responses. This manuscript investigates and describes a strategy for achieving controlled delivery of corticosteroids, based on a discovery that low molecular weight corticosteroid dimers can be processed into drug delivery implant materials using a broad range of established fabrication methods, without the use of polymers or excipients. These implants undergo surface erosion, achieving tightly controlled and reproducible drug release kinetics in vitro. As an example, when used as ocular implants in rats, a dexamethasone dimer implant is shown to effectively inhibit inflammation induced by lipopolysaccharide. In a rabbit model, dexamethasone dimer intravitreal implants demonstrate predictable pharmacokinetics and significantly extend drug release duration and efficacy (>6 months) compared to a leading commercial polymeric dexamethasone-releasing implant.
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Affiliation(s)
| | - Ian Parrag
- Ripple Therapeutics, Toronto, ON, Canada
| | | | | | | | | | - Adam Daley
- Ripple Therapeutics, Toronto, ON, Canada
| | - Fan Gu
- Ripple Therapeutics, Toronto, ON, Canada
| | | | | | - Ben Muirhead
- School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
| | - Emily Anne Hicks
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada
| | - Heather Sheardown
- School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
- Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada
| | - Leonid Kalachev
- Department of Mathematical Sciences, University of Montana, Missoula, MT, USA
| | | | | | - J Paul Santerre
- Ripple Therapeutics, Toronto, ON, Canada
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada
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19
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Sadasivam R, Packirisamy G, Shakya S, Goswami M. Non-invasive multimodal imaging of Diabetic Retinopathy: A survey on treatment methods and Nanotheranostics. Nanotheranostics 2021; 5:166-181. [PMID: 33564616 PMCID: PMC7868006 DOI: 10.7150/ntno.56015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/22/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetes Retinopathy (DR) is one of the most prominent microvascular complications of diabetes. It is one of the pre-eminent causes for vision impairment followed by blindness among the working-age population worldwide. The de facto cause for DR remains challenging, despite several efforts made to unveil the mechanism underlying the pathology of DR. There is quite less availability of the low cost pre-emptive theranostic imaging tools in terms of in-depth resolution, due to the multiple factors involved in the etiology of DR. This review work comprehensively explores the various reports and research works on all perspectives of diabetic retinopathy (DR), and its mechanism. It also discusses various advanced non-destructive imaging modalities, current, and future treatment approaches. Further, the application of various nanoparticle-based drug delivery strategies used for the treatment of DR are also discussed. In a nutshell, the present review work bolsters the pursuit of the development of an advanced non-invasive optical imaging modal with a nano-theranostic approach for the future diagnosis and treatment of DR and its associated ocular complications.
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Affiliation(s)
- Rajkumar Sadasivam
- Divyadrishti Imaging Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand-247667, India
| | - Gopinath Packirisamy
- Nanobiotechnology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand-247667, India
| | - Snehlata Shakya
- Department of clinical physiology, Lund University, Skåne University Hospital, Skåne, Sweden
| | - Mayank Goswami
- Divyadrishti Imaging Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand-247667, India
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20
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Rahić O, Tucak A, Omerović N, Sirbubalo M, Hindija L, Hadžiabdić J, Vranić E. Novel Drug Delivery Systems Fighting Glaucoma: Formulation Obstacles and Solutions. Pharmaceutics 2020; 13:E28. [PMID: 33375224 PMCID: PMC7824381 DOI: 10.3390/pharmaceutics13010028] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is considered to be one of the biggest health problems in the world. It is the main cause of preventable blindness due to its asymptomatic nature in the early stages on the one hand and patients' non-adherence on the other. There are several approaches in glaucoma treatment, whereby this has to be individually designed for each patient. The first-line treatment is medication therapy. However, taking into account numerous disadvantages of conventional ophthalmic dosage forms, intensive work has been carried out on the development of novel drug delivery systems for glaucoma. This review aims to provide an overview of formulation solutions and strategies in the development of in situ gel systems, nanosystems, ocular inserts, contact lenses, collagen corneal shields, ocular implants, microneedles, and iontophoretic devices. The results of studies confirming the effectiveness of the aforementioned drug delivery systems were also briefly presented.
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Affiliation(s)
- Ognjenka Rahić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Amina Tucak
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Naida Omerović
- Department of Clinical Pharmacy, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Merima Sirbubalo
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Lamija Hindija
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Jasmina Hadžiabdić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
| | - Edina Vranić
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71000 Sarajevo, Bosnia and Herzegovina; (A.T.); (M.S.); (L.H.); (J.H.)
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21
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Lehner E, Liebau A, Syrowatka F, Knolle W, Plontke SK, Mäder K. Novel biodegradable Round Window Disks for inner ear delivery of dexamethasone. Int J Pharm 2020; 594:120180. [PMID: 33338566 DOI: 10.1016/j.ijpharm.2020.120180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022]
Abstract
Drug delivery to the inner ear is an important and very challenging field. The cochlea is protected by several barriers that need to be overcome in the drug delivery process. Local drug delivery can avoid undesirable side effects arising from systemic drug delivery. We developed a biodegradable dexamethasone-loaded Round Window (RW) Disk based on poly(D,L-lactic-co-glycolic acid) (PLGA) for local drug therapy to the inner ear by RW membrane administration by a film-casting method. The optimal drying time was characterized by thermogravimetric analysis and differential scanning calorimetry. In addition, the mass and polymer degradation over time of drug release was measured in vitro showing a total mass loss of 70% after 3 weeks. Dexamethasone release was determined by a RW model setup using a polyethylene terephthalate membrane. We achieved a controlled release over 52 days. Ex vivo implantation of a RW Disk onto a guinea pig RW membrane indicated well-fitting properties of the drug delivery device leading to a close surface contact with the membrane and the successful proof of concept. The developed RW Disks could be new and promising drug delivery device to achieve effective local drug delivery to the inner ear for an extended time.
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Affiliation(s)
- E Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - A Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - F Syrowatka
- Interdisciplinary Center of Materials Science, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - W Knolle
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - S K Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - K Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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22
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Bhattacharya M, Sadeghi A, Sarkhel S, Hagström M, Bahrpeyma S, Toropainen E, Auriola S, Urtti A. Release of functional dexamethasone by intracellular enzymes: A modular peptide-based strategy for ocular drug delivery. J Control Release 2020; 327:584-594. [DOI: 10.1016/j.jconrel.2020.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/27/2020] [Accepted: 09/03/2020] [Indexed: 12/19/2022]
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Celik N, Khoramnia R, Auffarth GU, Sel S, Mayer CS. Complications of dexamethasone implants: risk factors, prevention, and clinical management. Int J Ophthalmol 2020; 13:1612-1620. [PMID: 33078113 DOI: 10.18240/ijo.2020.10.16] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/02/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate major complications after intravitreal injection of dexamethasone implants (Ozurdex) and their clinical management. METHODS In a retrospective observational study between 2014 and 2016 at two university hospitals, we reviewed the clinical records of 1241 consecutive macular edema patients treated with the dexamethasone implant, and separated severe adverse events in the injection procedure from those that were post-injection complications. We evaluated the cause and the outcomes in each case. RESULTS In twenty-one procedures (1.69%) we noticed significant complications during and after intravitreal injection of the dexamethasone implant. Complications related to the injection procedure were in one case, that a second implant was injected by mistake in the same eye on the same day. In another case, the implant lodged in the sclera during retraction of the injector needle. Leaking scleral tunnel at the injection site led to hypotony in another case. There were 10 cases of post-injection displacement of the implant into the anterior chamber and one case with a migrated and trapped device between the intraocular lens and an artificial iris. Displacement typically occurred in patients with preexisting risk factors: eyes with complicated intraocular lens implantation, iris reconstruction or iris defects or pseudophakic eyes after vitrectomy were prone to develop this complication. Displacement led to secondary corneal decompensation with pseudohypopyon. One case developed an endophthalmitis, and we observed four cases of retinal detachment. Two eyes presented with long-lasting hypotony due to ciliary insufficiency. CONCLUSION Treatment with the dexamethasone implant may cause various expected or unexpected complications that may have serious consequences for the patient and require further surgery. To reduce complications, clinicians should evaluate certain risk factors before scheduling patients for dexamethasone implant treatment and use proper injection techniques.
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Affiliation(s)
- Nil Celik
- Department of Ophthalmology, University Hospital of Heidelberg, Heidelberg 69120, Germany
| | - Ramin Khoramnia
- Department of Ophthalmology, University Hospital of Heidelberg, Heidelberg 69120, Germany
| | - Gerd U Auffarth
- Department of Ophthalmology, University Hospital of Heidelberg, Heidelberg 69120, Germany
| | - Saadettin Sel
- Department of Ophthalmology, University Hospital of Heidelberg, Heidelberg 69120, Germany
| | - Christian S Mayer
- Department of Ophthalmology, University Hospital of Heidelberg, Heidelberg 69120, Germany
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Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives. Drug Deliv Transl Res 2020; 11:866-893. [PMID: 32901367 DOI: 10.1007/s13346-020-00843-z] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.
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25
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Toto L, D'Aloisio R, Chiarelli AM, Di Antonio L, Evangelista F, D'Onofrio G, Merla A, Parravano M, Di Marzio G, Mastropasqua R. A Custom-Made Semiautomatic Analysis of Retinal Nonperfusion Areas After Dexamethasone for Diabetic Macular Edema. Transl Vis Sci Technol 2020; 9:13. [PMID: 32832220 PMCID: PMC7414703 DOI: 10.1167/tvst.9.7.13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/29/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the changes of retinal capillary nonperfusion areas and retinal capillary vessel density of the superficial capillary plexus (SCP) and deep capillary plexus in patients with diabetes with diabetic macular edema treated with an intravitreal dexamethasone implant (IDI). Methods We enrolled 28 patients with diabetic retinopathy and diabetic macular edema candidates to IDI. All patients underwent widefield optical coherence tomography angiography with PLEX Elite 9000 device with 15 × 9 mm scans centered on the foveal center at baseline, 1 month, 2 months, and 4 months after IDI. In all the patients, the variation of the retinal capillary nonperfusion areas and of the retinal vessel density of the SCP and deep capillary plexus were calculated using an automatic software written in Matlab (MathWorks, Natick, MA). Results During follow-up, SCP showed a statistically significant reduction of ischemic areas at 1 month after IDI (P = 0.04) and slightly increased not significantly thereafter (P = 0.15). The percentage of nonperfusion areas changed from 11.4% at baseline, to 6.3% at 1 month, 8.1%, at 2 months, and 10.2% at 4 months. The whole vessel density of SCP slightly increased (not significantly) from 35.30% at baseline to 38.00% at 1 month, and then decreased to 37.85% at 2 months and 36.04% at 4 months (P = 0.29). Retinal capillary nonperfusion areas and retinal vessel density at the deep capillary plexus did not change significantly (P = 0.31 and P = 0.73, respectively). Conclusions Widefield optical coherence tomography angiography showed a decrease in retinal capillary nonperfusion areas after dexamethasone implant suggesting a possible drug-related reperfusion of retinal capillaries particularly evident in the early period. Translational Relevance A custom-made automatic analysis of retinal nonperfusion areas may allow a better and precise evaluation of ischemic changes after intravitreal therapy.
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Affiliation(s)
- Lisa Toto
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Rossella D'Aloisio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Antonio Maria Chiarelli
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Luca Di Antonio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Federica Evangelista
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Giada D'Onofrio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Arcangelo Merla
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | | | - Guido Di Marzio
- Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, via dei Vestini 31, 66100, Italy
| | - Rodolfo Mastropasqua
- Institute of Ophthalmology, University of Modena and Reggio Emilia, Modena, Via del Pozzo 71, 41125, Italy
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Cicinelli MV, Cavalleri M, Lattanzio R, Bandello F. The current role of steroids in diabetic macular edema. EXPERT REVIEW OF OPHTHALMOLOGY 2020. [DOI: 10.1080/17469899.2020.1729743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Maria Vittoria Cicinelli
- Department of Ophthalmology, Scientific Institute San Raffaele, Vita-Salute University, Milan, Italy
| | - Michele Cavalleri
- Department of Ophthalmology, Scientific Institute San Raffaele, Vita-Salute University, Milan, Italy
| | - Rosangela Lattanzio
- Department of Ophthalmology, Scientific Institute San Raffaele, Vita-Salute University, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, Scientific Institute San Raffaele, Vita-Salute University, Milan, Italy
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27
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Lehner E, Gündel D, Liebau A, Plontke S, Mäder K. Intracochlear PLGA based implants for dexamethasone release: Challenges and solutions. Int J Pharm X 2019; 1:100015. [PMID: 31517280 PMCID: PMC6733303 DOI: 10.1016/j.ijpx.2019.100015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 11/19/2022] Open
Abstract
The effective treatment of diseases of the inner ear is currently an unmet medical need. Local controlled drug delivery to the cochlea is challenging due to the hidden location, small volume and high sensitivity of this organ. A local intracochlear delivery of drugs would avoid the problems of intratympanic (extracochlear) drug application, but is more invasive. The requirements for such a delivery system include a small size and appropriate flexibility. The delivery device must be rigid enough for surgical handling but also flexible to avoid traumatizing cochlear structures. We developed biodegradable dexamethasone loaded PLGA extrudates for the controlled intracochlear release. In order to achieve the desired flexibility, Polyethylene glycol (PEG) was used as a plasticizer. In addition to the drug release, the extrudates were characterized in vitro by differential scanning calorimetry (DSC) and texture analysis. Simulation of the pharmacokinetics of the inner ear support the expectation that a constant perilymph drug level is obtained after few hours and retained over several weeks. Ex vivo implantation of the extrudates into a guinea pig cochlea indicate that PEG containing extrudates have the desired balance between mechanical strength and flexibility for direct implantation into the cochlea. The location of the implant was visualized by computer tomography. In summary, we postulate that intracochlear administration of drug releasing biodegradable implants is a new and promising approach to achieve local drug delivery to the cochlea for an extended time.
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Affiliation(s)
- E. Lehner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - D. Gündel
- Department of Nuclear Medicine, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - A. Liebau
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - S. Plontke
- Department of Otorhinolaryngology-Head and Neck Surgery, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - K. Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany
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28
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Subrizi A, del Amo EM, Korzhikov-Vlakh V, Tennikova T, Ruponen M, Urtti A. Design principles of ocular drug delivery systems: importance of drug payload, release rate, and material properties. Drug Discov Today 2019; 24:1446-1457. [DOI: 10.1016/j.drudis.2019.02.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/10/2019] [Accepted: 02/01/2019] [Indexed: 12/26/2022]
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29
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García-Quintanilla L, Luaces-Rodríguez A, Gil-Martínez M, Mondelo-García C, Maroñas O, Mangas-Sanjuan V, González-Barcia M, Zarra-Ferro I, Aguiar P, Otero-Espinar FJ, Fernández-Ferreiro A. Pharmacokinetics of Intravitreal Anti-VEGF Drugs in Age-Related Macular Degeneration. Pharmaceutics 2019; 11:pharmaceutics11080365. [PMID: 31370346 PMCID: PMC6723750 DOI: 10.3390/pharmaceutics11080365] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 12/27/2022] Open
Abstract
Intravitreal administration of anti-vascular endothelial growth factor (VEGF) antibodies has become the standard treatment for Age-Related Macular Degeneration; however, the knowledge of their pharmacokinetics is limited. A comprehensive review of the preclinical and clinical pharmacokinetic data that were obtained in different studies with intravitreal bevacizumab, ranibizumab, and aflibercept has been conducted. Moreover, the factors that can influence the vitreous pharmacokinetics of these drugs, as well as the methods that were used in the studies for analytical determination, have been exposed. These anti-VEGF drugs present different charge and molecular weights, which play an important role in vitreous distribution and elimination. The pharmacokinetic parameters that were collected differ depending on the species that were involved in the studies and on physiological and pathological conditions, such as vitrectomy and lensectomy. Knowledge of the intravitreal pharmacokinetics of the anti-VEGF drugs that were used in clinical practice is of vital importance.
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Affiliation(s)
- Laura García-Quintanilla
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Andrea Luaces-Rodríguez
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain
| | - María Gil-Martínez
- Ophthalmology Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
| | - Cristina Mondelo-García
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Olalla Maroñas
- Genomic Medicine Group, Galician Public Foundation of Genomic Medicine, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Víctor Mangas-Sanjuan
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, 46100 Valencia, Spain
- Interuniversity Research Institute for Molecular Recognition and Technological Development, Polytechnic University of Valencia, 46100 Valencia, Spain
| | - Miguel González-Barcia
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Irene Zarra-Ferro
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Pablo Aguiar
- Nuclear Medicine Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain
- Molecular Imaging Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain.
| | - Anxo Fernández-Ferreiro
- Pharmacy Department, University Clinical Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute of Santiago de Compostela (FIDIS), 15706 Santiago de Compostela, Spain.
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain.
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30
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Castro-Balado A, Mondelo-García C, González-Barcia M, Zarra-Ferro I, Otero-Espinar FJ, Ruibal-Morell Á, Aguiar-Fernández P, Fernández-Ferreiro A. Ocular Biodistribution Studies using Molecular Imaging. Pharmaceutics 2019; 11:pharmaceutics11050237. [PMID: 31100961 PMCID: PMC6572242 DOI: 10.3390/pharmaceutics11050237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 05/05/2019] [Accepted: 05/07/2019] [Indexed: 02/07/2023] Open
Abstract
Classical methodologies used in ocular pharmacokinetics studies have difficulties to obtain information about topical and intraocular distribution and clearance of drugs and formulations. This is associated with multiple factors related to ophthalmic physiology, as well as the complexity and invasiveness intrinsic to the sampling. Molecular imaging is a new diagnostic discipline for in vivo imaging, which is emerging and spreading rapidly. Recent developments in molecular imaging techniques, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), allow obtaining reliable pharmacokinetic data, which can be translated into improving the permanence of the ophthalmic drugs in its action site, leading to dosage optimisation. They can be used to study either topical or intraocular administration. With these techniques it is possible to obtain real-time visualisation, localisation, characterisation and quantification of the compounds after their administration, all in a reliable, safe and non-invasive way. None of these novel techniques presents simultaneously high sensitivity and specificity, but it is possible to study biological procedures with the information provided when the techniques are combined. With the results obtained, it is possible to assume that molecular imaging techniques are postulated as a resource with great potential for the research and development of new drugs and ophthalmic delivery systems.
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Affiliation(s)
- Ana Castro-Balado
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Cristina Mondelo-García
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Miguel González-Barcia
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Irene Zarra-Ferro
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain.
| | - Álvaro Ruibal-Morell
- Nuclear Medicine Department, University Hospital of Santiago de Compostela (SERGAS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- Molecular Imaging Group. Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Pablo Aguiar-Fernández
- Nuclear Medicine Department, University Hospital of Santiago de Compostela (SERGAS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- Molecular Imaging Group. Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Anxo Fernández-Ferreiro
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain.
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Shah TJ, Conway MD, Peyman GA. Intracameral dexamethasone injection in the treatment of cataract surgery induced inflammation: design, development, and place in therapy. Clin Ophthalmol 2018; 12:2223-2235. [PMID: 30464383 PMCID: PMC6219274 DOI: 10.2147/opth.s165722] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cataract surgery is one of the most commonly performed surgeries worldwide, with nearly 20 million cases annually. Appropriate prophylaxis after cataract surgery can contribute to a safe and quick visual recovery with high patient satisfaction. Despite being the current standard of care, the use of multiple postoperative eye drops can create a significant burden on these patients, contributing to documented and significant non-adherence to the postoperative regimen. Over the past 25 years, there have been a few studies analyzing the use of intracameral dexamethasone (DXM) in controlling inflammation following cataract surgery. This review explores various drug delivery approaches for managing intraocular inflammation after cataract surgery, documenting the strengths and weaknesses of these options and examining the role of intracameral DXM (among these other strategies) in controlling postoperative intraocular inflammation. Intracameral DXM has a particular advantage over topical steroids in possibly decreasing postoperative inflammatory symptoms and objective anterior cell and flare scores. Compared to topical steroids, there may be a slightly less theoretical risk of significant intraocular pressure spikes and systemic absorption. In addition, surveys indicate patients prefer an intraoperative intracameral injection over a self-administered postoperative eye drop regimen. However, there are several adverse effects associated with intracameral DXM delivery that are not seen with the noninvasive topical approach. Although it is unlikely that intracameral DXM will replace topical medications as the standard management for postoperative inflammation, it is seemingly another safe and effective strategy for controlling postoperative inflammation after routine cataract surgery.
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Affiliation(s)
- Tirth J Shah
- Department of Ophthalmology, University of Arizona College of Medicine, Phoenix, Arizona, USA,
| | - Mandi D Conway
- Department of Ophthalmology, University of Arizona College of Medicine, Phoenix, Arizona, USA,
- Department of Ophthalmology, Tulane University College of Medicine, New Orleans, Louisiana, USA,
| | - Gholam A Peyman
- Department of Ophthalmology, University of Arizona College of Medicine, Phoenix, Arizona, USA,
- Department of Ophthalmology, Tulane University College of Medicine, New Orleans, Louisiana, USA,
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32
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Gu B, Papadimitrakopoulos F, Burgess DJ. PLGA microsphere/PVA hydrogel coatings suppress the foreign body reaction for 6 months. J Control Release 2018; 289:35-43. [PMID: 30261203 DOI: 10.1016/j.jconrel.2018.09.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 09/17/2018] [Accepted: 09/22/2018] [Indexed: 01/18/2023]
Abstract
The application of dexamethasone releasing poly (lactic-co-glycolic acid) (PLGA) microspheres embedded in a poly vinyl alcohol (PVA) hydrogel coatings have been successfully used in the suppression of the foreign body response (FBR) to implantable glucose sensors. In the current study, dexamethasone-loaded PLGA microspheres were prepared by blending two types of PLGA polymers (RG503H and DLG7E with MW of ca. 25 kDa and 113 kDa, respectively) to achieve long-term (6 months) inhibition of the FBR. The microsphere composition was optimized according to the in vitro drug release profiles. Microspheres with DLG7E/RG503H/dexamethasone = 70/13.3/16.7 wt% composition, when embedded in a PVA hydrogel, provided a continuous drug release for 6 months. By combining the aforementioned microspheres with microspheres composed solely of the DLG7E polymer within a similar PVA hydrogel realized an even longer (>7 months) in vitro drug release. A heat map was constructed to depict the daily in vitro drug released and elucidate possible lag phases that could affect the pharmacodynamic response. These drug-loaded implant coatings were investigated in vivo (rat model) and showed inhibition of the foreign body response for 6 months. These results suggest that the minimum effective daily dose to counter chronic inflammation is ca. 0.1 μg per mg of coating surrounding a 0.5 × 0.5 × 5 mm silicon implant (dummy sensor). Accordingly, these drug-eluting composite coatings can ensure long-term inflammation control for miniaturized implantable devices.
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Affiliation(s)
- Bing Gu
- University of Connecticut, School of Pharmacy, Storrs, CT 06269, USA
| | | | - Diane J Burgess
- University of Connecticut, School of Pharmacy, Storrs, CT 06269, USA.
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Whitcup SM, Cidlowski JA, Csaky KG, Ambati J. Pharmacology of Corticosteroids for Diabetic Macular Edema. Invest Ophthalmol Vis Sci 2018; 59:1-12. [PMID: 29297055 PMCID: PMC5961100 DOI: 10.1167/iovs.17-22259] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose Corticosteroids remain the mainstay of treatment for inflammatory diseases almost 80 years after their first clinical use. Topical ophthalmic formulations of corticosteroids have been available to treat disease of the anterior segment of the eye, but the approval of corticosteroids to treat vitreoretinal diseases, including vein occlusion, diabetic macular edema, and uveitis, has occurred only recently. Although most diseases respond to corticosteroid therapy, some patients are resistant to this therapy and side effects, including cataract and elevated intraocular pressure, can limit their use. The purpose of this review is to detail the basic science of corticosteroids focusing on differences in potency, drug delivery, pharmacokinetics, and gene activation, and how these differences affect safety and efficacy in the treatment of diabetic macular edema. Methods A review was conducted of basic science and pharmacology of the corticosteroids used to treat diabetic macular edema. Results Clinically available corticosteroids not only have differing potency and pharmacokinetics, but also activate different genes in different target tissues. These differences are associated with distinct efficacy, pharmacokinetic, and safety profiles. It is important to understand these differences in selecting corticosteroids to treat diabetic macular edema. Conclusions Recent advances in our understanding of the basic science of corticosteroids can explain clinical differences in these agents regarding efficacy and safety. Importantly, this understanding should allow the future discovery of additional novel corticosteroids to treat diabetic macular edema.
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Affiliation(s)
- Scott M Whitcup
- Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - John A Cidlowski
- Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangular Park, North Carolina, United States
| | - Karl G Csaky
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Jayakrishna Ambati
- Center for Advanced Vision Science, Department of Ophthalmology, Department of Pathology, Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States
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Influence of the test method on in vitro drug release from intravitreal model implants containing dexamethasone or fluorescein sodium in poly (d,l-lactide-co-glycolide) or polycaprolactone. Eur J Pharm Biopharm 2018; 127:270-278. [PMID: 29490233 DOI: 10.1016/j.ejpb.2018.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/20/2018] [Accepted: 02/23/2018] [Indexed: 11/20/2022]
Abstract
Sustained intravitreal dexamethasone (DX) administration with the FDA and EMA approved Ozurdex® implant is indicated for the treatment of macular edema and non-infectious uveitis. Since drug release after intravitreal application cannot be determined in vivo in human eyes, the characterization of drug release in vitro in addition to animal models is of great importance. The aim of this study was to provide information about the influence of the test method on the in vitro drug release from intravitreal model implants. The following test methods were used: a shaking incubator experiment in reagent tubes, the small volume USP apparatus 7, the Vitreous Model (VM) and a system simulating the impact of movement on the VM (Eye Movement System, EyeMoS). Cylindrical model implants composed of DX and PLGA (poly (d,l-lactide-co-glycolide)) and additional polycaprolactone (PCL) implants containing fluorescein sodium (FS) as a model substance were produced by hot melt extrusion and were cut to a length of approximately 6 mm. Drug release was studied in ringer buffer pH 7.4 and in a modified polyacrylamide gel (PAAG) as vitreous substitute. In combination with the VM, the shape, the gel structure and a partial liquefaction (50%) were simulated in vitro. Swelling, disintegration, fragmentation, surface enlargement and changes in shape of the PLGA model implants were observed during the drug release study. We experienced that not each of the test methods and media were suitable for drug release studies of the PLGA implants. Marked differences in the release profiles were observed depending on the employed test method. These results emphasize the necessity to understand the underlying in vivo processes and to transfer the knowledge about the release determining factors into reliable in vitro test systems.
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In vivo and in vitro sustained release of ranibizumab from a nanoporous thin-film device. Drug Deliv Transl Res 2017; 6:771-780. [PMID: 27178165 DOI: 10.1007/s13346-016-0298-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Current administration of ranibizumab and other therapeutic macromolecules to the vitreous and retina carries ocular risks, a high patient treatment burden, and compliance barriers that can lead to suboptimal treatment. Here we introduce a device that produces sustained release of ranibizumab in the vitreous cavity over the course of several months. Composed of twin nanoporous polymer thin films surrounding a ranibizumab reservoir, these devices provide release of ranibizumab over 16 weeks in vitro and 12 weeks in vivo, without exhausting the initial drug payload. Following implantation in vivo, devices were well-tolerated and showed no sign of immune response. This platform presents a potential solution to the challenge of delivering protein therapeutics to the vitreous and retina for sustained periods of time.
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Liu YC, Ng AHC, Ng XW, Yan P, Venkatraman SS, Mehta JS, Wong TT. Evaluation of a Sustained-Release Prednisolone Acetate Biodegradable Subconjunctival Implant in a Non-Human Primate Model. Transl Vis Sci Technol 2017; 6:9. [PMID: 29046829 PMCID: PMC5629924 DOI: 10.1167/tvst.6.5.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/22/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We evaluate the toxicity and plasma toxicokinetic (TK) profile of a biodegradable subconjunctival microrod for sustained prednisolone acetate (PA) release over 12 weeks in a non-human primate model. METHODS The biodegradable copolymer poly(l-lactide-co-ε-caprolactone) (PLC) and 40-wt% PA microrods were used and fashioned into 8 and 16 mm lengths. Twelve monkeys were divided into two treatment groups of PA-loaded and blank microrods, with six monkeys each receiving either 8- or 16-mm microrods subconjunctively implanted into both eyes. TK and hematology parameters were analyzed. Ophthalmic clinical evaluation, including slit-lamp and ophthalmoscopy examinations, was performed. RESULTS Over the study period of 12 weeks, the mean area under the plasma concentration-time curve was 45.7% higher, and the maximum plasma concentration was 17.2% lower for the animals treated with 40-wt% PA 16-mm microrods compared to 8-mm microrods (251.44 versus 172.54 hours × nanograms per milliliter and 8.53 versus 10.30 ng/mL, respectively). The PA release was significantly below the levels of assumed toxicity. There was no significant difference in the time to reach maximum concentration between the 8- and 16-mm microrod groups (7.33 and 8 hours; P = 0.421). Findings from clinical evaluation, hematology, and histopathology showed no ocular side effects and no significant adverse systemic effects. CONCLUSION The PA biodegradable microrods demonstrated safe toxicokinetics even with the larger size implant containing a higher amount of drug. The PA implant may be considered as a safe alternative to the application of topical PA eyedrops. TRANSLATIONAL RELEVANCE The results provide the evidence of the safety of implanting a steroid delivery system subconjunctively, offering an alternative to topical PA eyedrops.
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Affiliation(s)
- Yu-Chi Liu
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore.,Department of Corneal and External Eye Disease, Singapore National Eye Centre, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore
| | - Anthony Herr Cheun Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Xu Wen Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Peng Yan
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Subbu S Venkatraman
- School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore.,Department of Corneal and External Eye Disease, Singapore National Eye Centre, Singapore.,Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Tina T Wong
- Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore.,Ocular Therapeutics and Drug Delivery Group, Singapore Eye Research Institute, Singapore.,Department of Glaucoma, Singapore National Eye Centre, Singapore
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Acute bacterial endophthalmitis following intravitreal dexamethasone implant: A case report and review of literature. Saudi J Ophthalmol 2017; 31:51-54. [PMID: 28337065 PMCID: PMC5352935 DOI: 10.1016/j.sjopt.2016.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 11/02/2016] [Accepted: 12/06/2016] [Indexed: 11/24/2022] Open
Abstract
Endophthalmitis following intravitreal dexamethasone (DEX) implant has been rarely reported. This report describes the case of a 70-year-old male who underwent intravitreal DEX implant injection under aseptic conditions, for diabetic macular edema. He developed a clinical picture suggestive of endophthalmitis within 2 weeks of the injection, and vitreous culture grew coagulase negative Staphylococcus. He was treated with intravitreal antibiotics followed by pars plana vitrectomy and removal of the implant. This was followed by resolution of the infection with a favorable final visual outcome. The challenges faced during surgical management of this case are discussed.
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Jiang K, Weaver JD, Li Y, Chen X, Liang J, Stabler CL. Local release of dexamethasone from macroporous scaffolds accelerates islet transplant engraftment by promotion of anti-inflammatory M2 macrophages. Biomaterials 2017; 114:71-81. [DOI: 10.1016/j.biomaterials.2016.11.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/03/2016] [Accepted: 11/04/2016] [Indexed: 02/05/2023]
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Rodríguez Villanueva J, Rodríguez Villanueva L, Guzmán Navarro M. Pharmaceutical technology can turn a traditional drug, dexamethasone into a first-line ocular medicine. A global perspective and future trends. Int J Pharm 2016; 516:342-351. [PMID: 27889587 DOI: 10.1016/j.ijpharm.2016.11.053] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/20/2016] [Accepted: 11/22/2016] [Indexed: 01/04/2023]
Abstract
Dexamethasone is one of the most prescribed glucocorticoids. It is effective and safe in the treatment of a wide variety of ocular conditions, including anterior and posterior segment inflammation. However, its half-life in the vitreous humor is very short, which means that it typically requires frequent administrations, thus reducing patient adherence and causing therapeutic failure. Innovative dexamethasone delivery systems have been designed in an attempt to achieve sustained release and targeting. The FDA has approved dexamethasone implants for the treatment of macular edema secondary to retinal vein occlusion and posterior segment noninfectious uveitis. Lenses, micro- and nanoparticles, liposomes, micelles and dendrimers are also proving to be adequate systems for maintaining optimal dexamethasone levels in the site of action. Pharmaceutical technology is turning a classical drug, dexamethasone, into a fashionable medicine.
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Affiliation(s)
- Javier Rodríguez Villanueva
- Biomedical Sciences Department, Pharmacy and Pharmaceutical Technology Unit, Faculty of Pharmacy, University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; Faculty of Pharmacy, University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600 28805 Alcalá de Henares, Madrid, Spain.
| | - Laura Rodríguez Villanueva
- Faculty of Pharmacy, University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600 28805 Alcalá de Henares, Madrid, Spain
| | - Manuel Guzmán Navarro
- Biomedical Sciences Department, Pharmacy and Pharmaceutical Technology Unit, Faculty of Pharmacy, University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; Faculty of Pharmacy, University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600 28805 Alcalá de Henares, Madrid, Spain
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Pacella F, Romano MR, Turchetti P, Tarquini G, Carnovale A, Mollicone A, Mastromatteo A, Pacella E. An eighteen-month follow-up study on the effects of Intravitreal Dexamethasone Implant in diabetic macular edema refractory to anti-VEGF therapy. Int J Ophthalmol 2016; 9:1427-1432. [PMID: 27803859 DOI: 10.18240/ijo.2016.10.10] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 04/14/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the long-term efficacy and safety of dexamethasone implants in subjects affected by diabetic macular edema (DME) resistant to anti-vascular endothelial growth factor (VEGF) therapy. METHODS Thirty-two DME patients were enrolled. A 700 microgram slow release Intravitreal Dexamethasone Implant (Ozurdex®) was placed in the vitreous cavity. All patients were followed for 18mo. Best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) and central macular thickness (CMT) exams were carried out at baseline (T0) and after 1 (T1), 3 (T3), 4 (T4), 6 (T6), 9 (T9), 12 (T12), 15 (T15), and 18mo (T18) post injection. RESULTS Repeated measures ANOVA showed an effect of treatment on ETDRS (P<0.0001). Post hoc analyses revealed that ETDRS values were significantly increased at T1, T3, T4, T9, and T15 (P<0.001) as compared to baseline value (T0). At T6, T12, and T18, ETDRS values were still statistically higher than baseline (P<0.001 vs T0). However, at these time points, we observed a trend to return to baseline conditions. ANOVA also showed an effect of treatment (P<0.0001). CMT decreased significantly at T1, T3, T4, T9, and T15 (P<0.001). At T6 (P<0.01), T12 and T18 (P<0.001) CMT was also significantly lower than T0 although a trend to return to the baseline conditions was also observed. CONCLUSION Our findings demonstrate that Intravitreal Dexamethasone Implant is a good option to improve BCVA and CMT in DME patients resistant to anti-VEGF therapy. Our data also show that the use of drugs administered directly into the vitreous allows achieving appropriate and long-lasting concentration at the site of disease without systemic side effects.
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Affiliation(s)
- Fernanda Pacella
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome 00161, Italy
| | | | - Paolo Turchetti
- National Institute for Health, Migration and Poverty (INMP/NIHMP), Rome 00153, Italy
| | - Giovanna Tarquini
- Department of Internal Medicine and Clinical Specialities, Sapienza University of Rome, Rome 00161, Italy
| | - Anna Carnovale
- Department of Internal Medicine and Clinical Specialities, Sapienza University of Rome, Rome 00161, Italy
| | - Antonella Mollicone
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome 00161, Italy
| | - Alessandra Mastromatteo
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome 00161, Italy
| | - Elena Pacella
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome 00161, Italy
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Amsden BG, Marecak D. Long-Term Sustained Release from a Biodegradable Photo-Cross-Linked Network for Intraocular Corticosteroid Delivery. Mol Pharm 2016; 13:3004-12. [DOI: 10.1021/acs.molpharmaceut.6b00358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Brian G. Amsden
- Department
of Chemical Engineering, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - Dale Marecak
- Department
of Chemical Engineering, Queen’s University, Kingston, Ontario, Canada K7L 3N6
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42
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Im JC, Shin JP, Kim IT, Park DH. Does Intravitreal Dexamethasone Implant Fragmentation Affect Clinical Outcomes in Macular Edema from Branch Retinal Vein Occlusion. Ophthalmologica 2016; 236:74-80. [DOI: 10.1159/000446880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/17/2016] [Indexed: 11/19/2022]
Abstract
Purpose: The aim of this study was to evaluate the effect of intravitreal dexamethasone implant fragmentation on clinical outcomes in branch retinal vein occlusion (BRVO)-induced macular edema (ME). Methods: All consecutive patients receiving an intravitreal dexamethasone implant for BRVO-induced ME were divided into two groups depending on whether the implant was intact or had fragmented into two or more pieces on postoperative day 1. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), and central subfield thickness (CST) on spectral-domain optical coherence tomography were measured for 6 months. Results: Among 68 patients, the implant was fragmented in 6 (8.8%) and intact in 62 (91.2%) eyes. The two groups did not differ in BCVA and CST at any time point (all p > 0.05). There was no difference in the ME recurrence rate, frequency of IOP elevation, and cataract progression between the two groups (all p > 0.05). Conclusion: Fragmentation seemed not to influence clinical outcomes of intravitreal dexamethasone implantation during 6 months or to alter the frequency of adverse events.
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Tsang AC, Virgili G, Abtahi M, Gottlieb CC. Intravitreal Dexamethasone Implant for the Treatment of Macular Edema in Chronic Non-infectious Uveitis. Ocul Immunol Inflamm 2016; 25:685-692. [PMID: 27191685 DOI: 10.3109/09273948.2016.1160130] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To report observations on the single and repeat use of the dexamethasone (DEX) intravitreal implant (Ozurdex; Allergan, Inc, Irvine, CA) for the treatment of macular edema in patients with non-infectious posterior segment uveitis. METHODS A chart review of 15 consecutive patients (25 eyes) was conducted. The primary outcome measure of the first and subsequent implants was central retinal thickness (CRT) on spectral-domain optical coherence tomography (sdOCT). Secondary outcomes were best-corrected visual acuity (BCVA), time to repeat implant, and adverse events. Multilevel mixed-effects linear regression was used to determine the effect of the DEX implant compared with baseline. The Kaplan-Meier estimator was used to examine survival from relapse. RESULTS A total of 35 implants on 25 eyes of 15 patients were included in the analysis. Of these, 91.4% (32 of 35 eyes) had a reduction in CRT and 80% (20 of 25 eyes) had improved BCVA. After the first DEX implant, CRT decreased from 590 µm (SE: 28 µm) at baseline to 370 µm (SE: 31 µm) at 3 months (p < 0.001). The logMAR VA was 0.614 (SE: 0.089) at baseline and improved to 0.35 (SE: 0.10, p = 0.002), reaching a statistically significant difference at 3 months. A repeat implant led to VA improvement of -0.184 logMAR (SE: 0.171 logMAR) and CRT reduction of -291 µm (SE: 74 µm). There was no significant difference in effect between the first repeat implant and the initial implant. Kaplan-Meier estimates of treatment success were 72% between 3 and 6 months. CONCLUSIONS The DEX implant is an effective adjunct treatment to systemic corticosteroid or immunomodulatory therapy. Additional research is required to determine the efficacy of DEX implant as monotherapy for controlling chronic uveitic macular edema.
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Affiliation(s)
- Adrian C Tsang
- a Ottawa Hospital Research Institute , Ottawa , Ontario , Canada.,b Faculty of Medicine , University of Ottawa , Ottawa , Ontario , Canada
| | - Gianni Virgili
- c Department of Ophthalmology , University of Florence , Florence , Italy
| | - Maryam Abtahi
- a Ottawa Hospital Research Institute , Ottawa , Ontario , Canada.,d University of Ottawa Eye Institute , Ottawa , Ontario , Canada
| | - Chloe C Gottlieb
- a Ottawa Hospital Research Institute , Ottawa , Ontario , Canada.,b Faculty of Medicine , University of Ottawa , Ottawa , Ontario , Canada.,d University of Ottawa Eye Institute , Ottawa , Ontario , Canada
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44
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Yang Y, Bailey C, Loewenstein A, Massin P. INTRAVITREAL CORTICOSTEROIDS IN DIABETIC MACULAR EDEMA: PHARMACOKINETIC CONSIDERATIONS. Retina 2015; 35:2440-9. [PMID: 26352555 PMCID: PMC4697357 DOI: 10.1097/iae.0000000000000726] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE To review the relationship between kinetics, efficacy, and safety of several corticosteroid formulations for the treatment of diabetic macular edema. METHODS Reports of corticosteroid use for the treatment of diabetic macular edema were identified by a literature search, which focused on the pharmacokinetics, efficacy, and safety of these agents in preclinical animal models and clinical trials. RESULTS Available corticosteroids for diabetic macular edema treatment include intravitreal triamcinolone acetonide, dexamethasone, and fluocinolone acetonide. Because of differences in solubility and bioavailability, various delivery mechanisms are used. Bioerodible delivery systems achieve higher maximum concentrations than nonbioerodible formulations. There is a relationship between visual gains and drug persistence in the intravitreal compartment. Safety effects were more complex; level of intravitreal triamcinolone acetonide exposure is related to development of elevated intraocular pressure and cataract; this does not seem to be the case for dexamethasone, where two different doses showed similar mean intraocular pressure and incidence of cataract surgery. With fluocinolone acetonide, rates of intraocular pressure elevations requiring surgery seem to be dose related; rates of cataract extraction were similar regardless of dose. CONCLUSION Available corticosteroids for diabetic macular edema exhibit different pharmacokinetic profiles that impact efficacy and adverse events and should be taken into account when developing individualized treatment plans.
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Affiliation(s)
- Yit Yang
- Royal Wolverhampton Hospitals NHS Trust, Wolverhampton, United Kingdom
| | - Clare Bailey
- University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Anat Loewenstein
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Pascale Massin
- Department of Ophthalmology, Lariboisière Hospital, Paris, France
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45
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Kuo HK, Chen YH, Wu PC, Kuo YH. The Effects of Ozurdex® (Dexamethasone Intravitreal Implant) on Experimental Proliferative Vitreoretinopathy. Ophthalmologica 2015; 233:198-203. [DOI: 10.1159/000371901] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/29/2014] [Indexed: 11/19/2022]
Abstract
Purpose: To investigate a new sustained-release formulation of dexamethasone (Ozurdex®) for inhibiting proliferative vitreoretinopathy (PVR) and its effect on the expression of retinal glial reaction and inflammation in experimental PVR eyes. Methods: We used 30 pigmented rabbits for this study. One week after gas compression, the eyes were injected with 5 × 104 retinal pigment epithelial cells into the vitreous cavity to induce PVR. Concurrently, one eye also received an intravitreal injection of Ozurdex; the other eye was used as a control. PVR was graded by indirect ophthalmoscopy on days 1, 3, 7, 14, 21, and 28. The expression of the retinal glial reaction and inflammation in experimental PVR eyes were evaluated by Western blot analysis. Results: PVR severity increased gradually and peaked after 14 days, and no differences in PVR severity between the study and control groups were observed at any time point. The expression of glial fibrillary acid protein (GFAP) increased on days 7 and 14 in both the PVR control and study groups. While the use of Ozurdex in the study group showed less GFAP expression, this difference was not significant. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 significantly increased on days 7 and 14 in PVR control eyes. There was a significant difference in TNF-α between PVR control eyes and Ozurdex-treated eyes on days 7 (p < 0.001) and 14 (p = 0.019). Ozurdex in the study group showed lower IL-6 expression; however, this difference was not significant on days 7 (p = 0.063) and 14 (p = 0.052). Conclusions: The intravitreal injection of Ozurdex suppressed the expression of inflammatory markers; however, it did not mitigate the severity of experimental PVR in this animal model.
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Cebeci Z, Kir N. Role of implants in the treatment of diabetic macular edema: focus on the dexamethasone intravitreal implant. Diabetes Metab Syndr Obes 2015; 8:555-66. [PMID: 26604809 PMCID: PMC4655951 DOI: 10.2147/dmso.s73540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Diabetic macular edema (DME) is the leading cause of sight-threatening complication in diabetic patients, and several treatment modalities have been developed and evaluated to treat this pathology. Intravitreal agents, such as anti-vascular endothelial growth factors (anti-VEGF) or corticosteroids, have become more popular in recent years and are widely used for treating DME. Sustained release drugs appear to be mentioned more often nowadays for extending the period of intravitreal activity, and corticosteroids play a key role in inhibiting the inflammatory process in DME. A potent corticosteroid, dexamethasone (Ozurdex(®)), in the form of an intravitreal implant, has been approved for various ocular etiologies among which DME is also one. This review evaluates the role of implants in the treatment of DME, mainly focusing on the dexamethasone intravitreal implant.
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Affiliation(s)
- Zafer Cebeci
- Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey
- Correspondence: Zafer Cebeci, Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa 34390, Istanbul, Turkey, Tel +90 212 414 2000, Fax +90 212 414 2026, Email
| | - Nur Kir
- Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey
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