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Hansen ME, Ibrahim Y, Desai TA, Koval M. Nanostructure-Mediated Transport of Therapeutics through Epithelial Barriers. Int J Mol Sci 2024; 25:7098. [PMID: 39000205 PMCID: PMC11241453 DOI: 10.3390/ijms25137098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/24/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
The ability to precisely treat human disease is facilitated by the sophisticated design of pharmacologic agents. Nanotechnology has emerged as a valuable approach to creating vehicles that can specifically target organ systems, effectively traverse epithelial barriers, and protect agents from premature degradation. In this review, we discuss the molecular basis for epithelial barrier function, focusing on tight junctions, and describe different pathways that drugs can use to cross barrier-forming tissue, including the paracellular route and transcytosis. Unique features of drug delivery applied to different organ systems are addressed: transdermal, ocular, pulmonary, and oral delivery. We also discuss how design elements of different nanoscale systems, such as composition and nanostructured architecture, can be used to specifically enhance transepithelial delivery. The ability to tailor nanoscale drug delivery vehicles to leverage epithelial barrier biology is an emerging theme in the pursuit of facilitating the efficacious delivery of pharmacologic agents.
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Affiliation(s)
- M. Eva Hansen
- University of California Berkeley-University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA;
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | - Yasmin Ibrahim
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Graduate Program in Biochemistry, Cell and Developmental Biology, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30322, USA
| | - Tejal A. Desai
- University of California Berkeley-University of California San Francisco Graduate Program in Bioengineering, San Francisco, CA 94143, USA;
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94143, USA
- School of Engineering, Brown University, Providence, RI 02912, USA
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Rupenthal ID, Agarwal P. Progress in Ocular Drug Delivery: Challenges and Constraints. Handb Exp Pharmacol 2024; 284:267-288. [PMID: 37620616 DOI: 10.1007/164_2023_693] [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: 08/26/2023]
Abstract
The eye has several dynamic and static barriers in place to limit the entry of foreign substances including therapeutics. As such, efficient drug delivery, especially to posterior segment tissues, has been challenging. This chapter describes the anatomical and physiological challenges associated with ocular drug delivery before discussing constraints with regard to formulation parameters. Finally, it gives an overview of advanced drug delivery technologies with a specific focus on recently marketed and late-stage clinical trial products.
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Affiliation(s)
- Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
| | - Priyanka Agarwal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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3
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Allison C, Jiménez A, Ramajayam K, Haemmerich D, Zderic V. Therapeutic Ultrasound for Enhanced Corneal Permeability to Macromolecules. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024; 43:127-136. [PMID: 37842972 DOI: 10.1002/jum.16346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/30/2023] [Accepted: 09/17/2023] [Indexed: 10/17/2023]
Abstract
OBJECTIVES Topically applied macromolecules have the potential to provide vision-saving treatments for many of the leading causes of blindness in the United States. The aim of this study was to determine if ultrasound can be applied to increase transcorneal drug delivery of macromolecules without dangerously overheating surrounding ocular tissues. METHODS Dissected corneas of adult rabbits were placed in a diffusion cell between a donor compartment filled with a solution of macromolecules (40, 70 kDa, or 150 kDa) and a receiver compartment. Each cornea was exposed to the drug solution for 60 minutes, with the experimental group receiving 5 minutes of continuous ultrasound or 10 minutes of pulsed ultrasound at a 50% duty cycle (pulse repetition frequency of 500 ms on, 500 ms off) at the beginning of treatment. Unfocused circular ultrasound transducers were operated at 0.5 to 1 W/cm2 intensity and at 600 kHz frequency. RESULTS The greatest increase in transcorneal drug delivery seen was 1.2 times (P < .05) with the application of pulsed ultrasound at 0.5 W/cm2 and 600 kHz for 10 minutes with 40 kDa macromolecules. Histological analysis revealed structural damage mostly in the corneal epithelium, with most damage occurring at the epithelial surface. CONCLUSIONS This study suggests that ultrasound may be used for enhancing transcorneal delivery of macromolecules of lower molecular weights. Further research is needed on the long-term effects of ultrasound parameters used in this study on human ocular tissues.
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Affiliation(s)
- Claire Allison
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Annette Jiménez
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Krishna Ramajayam
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
| | - Dieter Haemmerich
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
| | - Vesna Zderic
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
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Ansari M, Kulkarni YA, Singh K. Advanced Technologies of Drug Delivery to the Posterior Eye Segment Targeting Angiogenesis and Ocular Cancer. Crit Rev Ther Drug Carrier Syst 2024; 41:85-124. [PMID: 37824419 DOI: 10.1615/critrevtherdrugcarriersyst.2023045298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Retinoblastoma (RB), a childhood retinal cancer is caused due to RB1 gene mutation which affects the child below 5 years of age. Angiogenesis has been proven its role in RB metastasis due to the presence of vascular endothelial growth factor (VEGF) in RB cells. Therefore, exploring angiogenic pathway by inhibiting VEGF in treating RB would pave the way for future treatment. In preclinical studies, anti-VEGF molecule have shown their efficacy in treating RB. However, treatment requires recurrent intra-vitreal injections causing various side effects along with patient nonadherence. As a result, delivery of anti-VEGF agent to retina requires an ocular delivery system that can transport it in a non-invasive manner to achieve patient compliance. Moreover, development of these type of systems are challenging due to the complicated physiological barriers of eye. Adopting a non-invasive or minimally invasive approach for delivery of anti-VEGF agents would not only address the bioavailability issues but also improve patient adherence to therapy overcoming the side effects associated with invasive approach. The present review focuses on the eye cancer, angiogenesis and various novel ocular drug delivery systems that can facilitate inhibition of VEGF in the posterior eye segment by overcoming the eye barriers.
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Affiliation(s)
- Mudassir Ansari
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS, Mumbai 400056, India
| | - Yogesh A Kulkarni
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS, Mumbai 400056, India
| | - Kavita Singh
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS, Mumbai 400056, India
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Binkhathlan Z, Ali R, Alomrani AH, Abul Kalam M, Alshamsan A, Lavasanifar A. Role of Polymeric Micelles in Ocular Drug Delivery: An Overview of Decades of Research. Mol Pharm 2023; 20:5359-5382. [PMID: 37769017 DOI: 10.1021/acs.molpharmaceut.3c00598] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Local drug delivery to the eye through conventional means has faced many challenges due to three essential barriers: (a) the complex structure of the cornea limiting drug absorption, (b) the capacity of ocular absorptive cells in drug metabolism, and (c) the washing effect of eye tears. Polymeric micelles (PMs) have been the focus of much interest for ocular drug delivery due to several advantages they provide for this application, including the capacity for the solubilization of hydrophobic drugs, nonirritability, nanoscopic diameter, and the clarity of their aqueous solution not interfering with vision. The potential to increase the release and residence time of incorporated medication at the site of absorption is also a bonus advantage for these delivery systems. This Review covers research conducted on single or mixed micelles prepared from small amphiphilic molecules, copolymers (diblock, triblock, and graft), and gel systems containing micelles. The purpose of this review is to provide an update on the status of micellar ocular delivery systems for different indications, with a focus on preclinical and clinical drug development. In this context, we are discussing the anatomy of the eye, various ocular barriers, different micellar formulations, and their benefits in ocular drug delivery, as well as the role of PMs in the management of ocular diseases both in preclinical models and in clinic. The encouraging preclinical effectiveness findings from experiments conducted in both laboratory settings and live animals have paved the way for the advancement of micellar systems in clinical trials for ocular administration and the first nanomicallar formulation approved for clinical use by the United States Food and Drug Administration (marketed as Cequa by Sun Pharmaceuticals).
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Affiliation(s)
- Ziyad Binkhathlan
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Nanobiotechnology Research Unit, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Raisuddin Ali
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Nanobiotechnology Research Unit, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Abdullah H Alomrani
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Nanobiotechnology Research Unit, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Mohd Abul Kalam
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Nanobiotechnology Research Unit, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Aws Alshamsan
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
- Nanobiotechnology Research Unit, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
- Department of Chemical and Material Engineering, University of Alberta, Edmonton, Alberta T6G 2 V4, Canada
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Iselin KC, Bachmann LM, Thiel MA, Sanak F, Baenninger PB, Kaufmann C. A fluorophotometric comparison of anterior chamber riboflavin delivery via corneal application and fornix instillation. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2023; 98:627-632. [PMID: 37748681 DOI: 10.1016/j.oftale.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 08/09/2023] [Indexed: 09/27/2023]
Abstract
INTRODUCTION AND OBJECTIVES We investigated whether riboflavin self-administration by patients could be a feasible option for corneal cross-linking, given the considerable resources required to impregnate the cornea with riboflavin. We analysed whether administering riboflavin in the inferior fornix (the site of self-administration) results in non-inferior riboflavin concentrations as when applied directly on the cornea (the site of administration by medical personnel). PATIENTS AND METHODS We conducted a prospective study to evaluate riboflavin concentrations at six time-points (baseline, 5, 15, 30, 45 and 60min) in 18 healthy volunteers for each of two application sites: cornea and fornix. Anterior chamber riboflavin (Peschke® TE 0.25%) concentrations were measured by fluorophotometry (Fluorotron™ Master FM-2). RESULTS For the two application sites cornea and fornix, participants did not differ in terms of age and sex. At baseline, the autofluorescence in the anterior chamber was 16.7ng/mL (SD 5.5) and 14.6ng/mL (SD 4.6) (P=.221). After 30min, anterior chamber fluorescein concentrations had risen to 55.1ng/mL (SD 25.5) and 46.1ng/mL (SD 25.1) (P=.293) without a further relevant increase by 60min. CONCLUSIONS This study found that applying riboflavin drops in the inferior fornix was non-inferior to applying it directly to the cornea, based on fluorophotometric measurements of anterior chamber riboflavin concentrations. This suggests that self-application of riboflavin is feasible in terms of corneal riboflavin impregnation.
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Affiliation(s)
- K C Iselin
- Departamento de Oftalmología, Hospital Cantonal de Lucerna, Lucerna, Switzerland
| | | | - M A Thiel
- Departamento de Oftalmología, Hospital Cantonal de Lucerna, Lucerna, Switzerland
| | - F Sanak
- Departamento de Oftalmología, Hospital Cantonal de Lucerna, Lucerna, Switzerland
| | - P B Baenninger
- Departamento de Oftalmología, Hospital Cantonal de Lucerna, Lucerna, Switzerland
| | - C Kaufmann
- Departamento de Oftalmología, Hospital Cantonal de Lucerna, Lucerna, Switzerland.
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Zdraveva E, Dolenec T, Tominac Trcin M, Govorčin Bajsić E, Holjevac Grgurić T, Tomljenović A, Dekaris I, Jelić J, Mijovic B. The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair. Polymers (Basel) 2023; 15:2663. [PMID: 37376309 DOI: 10.3390/polym15122663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient's vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair.
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Affiliation(s)
- Emilija Zdraveva
- Faculty of Textile Technology, University of Zagreb, 10000 Zagreb, Croatia
| | - Tamara Dolenec
- Department of Transfusion and Regenerative Medicine, Sestre Milosrdnice University Hospital Center, 10000 Zagreb, Croatia
| | | | - Emi Govorčin Bajsić
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia
| | | | | | - Iva Dekaris
- Faculty of Medicine, University of Rijeka, Bilić Vision Polyclinic, 10000 Zagreb, Croatia
| | - Josip Jelić
- Faculty of Textile Technology, University of Zagreb, 10000 Zagreb, Croatia
| | - Budimir Mijovic
- Faculty of Textile Technology, University of Zagreb, 10000 Zagreb, Croatia
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Gedik G, Oztabag CK, Sarp O, Nazli H, Tiranbesli G, Kurt AH, Dinc E, Ayaz L. Development of Anti-VEGF Prolonged Release Drug Delivery System Containing PLL Dendrimer and Hyaluronic Acid. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022. [DOI: 10.1134/s1068162022060115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Karami TK, Hailu S, Feng S, Graham R, Gukasyan HJ. Eyes on Lipinski's Rule of Five: A New "Rule of Thumb" for Physicochemical Design Space of Ophthalmic Drugs. J Ocul Pharmacol Ther 2021; 38:43-55. [PMID: 34905402 PMCID: PMC8817695 DOI: 10.1089/jop.2021.0069] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The study objective was to investigate molecular thermodynamic properties of approved ophthalmic drugs and derive a framework outlining physicochemical design space for product development. Unlike the methodology used to obtain molecular descriptors for assessment of drug-like properties by Lipinski's Rule of 5 (Ro5), this work presents a retrospective approach based on in silico analysis of molecular thermodynamic properties beyond Ro5 parameters (ie, free energy of distribution/partitioning in octanol/water, dynamic polar surface area, distribution coefficient, and solubility at physiological pH) by using 145 marketed ophthalmic drugs. The study's focus was to delineate inherent molecular parameters explicitly important for ocular permeability and absorption from topical eye drops. A comprehensive parameter distribution analysis on ophthalmic drugs’ molecular properties was performed. Frequencies in distribution analyses provided groundwork for physicochemical parameter limits of molecular thermodynamic properties having impact on corneal permeability and topical ophthalmic drug delivery. These parameters included free energy of partitioning (ΔGo/w) calculated based on thermodynamic free energy equation, distribution coefficient at physiological pH (clog DpH7.4), topological polar surface area (TPSA), and aqueous solubility (Sint, SpH7.4) with boundaries of clog DpH7.4 ≤4.0, TPSA ≤250 Å2, ΔGo/w ≤20 kJ/mol (4.8 kcal/mol), and solubility (Sint and SpH7.4) ≥1 μM, respectively. The theoretical free energy of partitioning model streamlined calculation of changes in the free energy of partitioning, Δ(ΔGo/w), as a measure of incremental improvements in corneal permeability for congeneric series. The above parameter limits are proposed as “rules of thumb” for topical ophthalmic drugs to assess risks in developability.
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Affiliation(s)
- Thomas K Karami
- Pharmaceutical Sciences, Allergan plc, an AbbVie Company, Irvine, California, USA
| | - Shumet Hailu
- Pharmaceutical Sciences, Allergan plc, an AbbVie Company, Irvine, California, USA
| | - Shaoxin Feng
- Pharmaceutical Sciences, Allergan plc, an AbbVie Company, Irvine, California, USA
| | - Richard Graham
- Pharmaceutical Sciences, Allergan plc, an AbbVie Company, Irvine, California, USA
| | - Hovhannes J Gukasyan
- Pharmaceutical Sciences, Allergan plc, an AbbVie Company, Irvine, California, USA
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Mofidfar M, Abdi B, Ahadian S, Mostafavi E, Desai TA, Abbasi F, Sun Y, Manche EE, Ta CN, Flowers CW. Drug delivery to the anterior segment of the eye: A review of current and future treatment strategies. Int J Pharm 2021; 607:120924. [PMID: 34324989 PMCID: PMC8579814 DOI: 10.1016/j.ijpharm.2021.120924] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 01/03/2023]
Abstract
Research in the development of ophthalmic drug formulations and innovative technologies over the past few decades has been directed at improving the penetration of medications delivered to the eye. Currently, approximately 90% of all ophthalmic drug formulations (e.g. liposomes, micelles) are applied as eye drops. The major challenge of topical eye drops is low bioavailability, need for frequent instillation due to the short half-life, poor drug solubility, and potential side effects. Recent research has been focused on improving topical drug delivery devices by increasing ocular residence time, overcoming physiological and anatomical barriers, and developing medical devices and drug formulations to increase the duration of action of the active drugs. Researchers have developed innovative technologies and formulations ranging from sub-micron to macroscopic size such as prodrugs, enhancers, mucus-penetrating particles (MPPs), therapeutic contact lenses, and collagen corneal shields. Another approach towards the development of effective topical drug delivery is embedding therapeutic formulations in microdevices designed for sustained release of the active drugs. The goal is to optimize the delivery of ophthalmic medications by achieving high drug concentration with prolonged duration of action that is convenient for patients to administer.
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Affiliation(s)
| | - Behnam Abdi
- Institute of Polymeric Materials (IPM), Sahand University of Technology, New Town of Sahand, Tabriz, Iran; Faculty of Polymer Engineering, Sahand University of Technology, New Town of Sahand, Tabriz, Iran
| | - Samad Ahadian
- Terasaki Institute for Biomedical Innovation, Los Angeles, CA, USA
| | - Ebrahim Mostafavi
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cardiovascular Institute, Stanford University, CA, USA
| | - Tejal A Desai
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA
| | - Farhang Abbasi
- Institute of Polymeric Materials (IPM), Sahand University of Technology, New Town of Sahand, Tabriz, Iran; Faculty of Polymer Engineering, Sahand University of Technology, New Town of Sahand, Tabriz, Iran
| | - Yang Sun
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA.
| | - Edward E Manche
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA.
| | - Christopher N Ta
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA.
| | - Charles W Flowers
- USC Roski Eye Institute, University of Southern California, Los Angeles, CA, USA.
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Matthiesen I, Voulgaris D, Nikolakopoulou P, Winkler TE, Herland A. Continuous Monitoring Reveals Protective Effects of N-Acetylcysteine Amide on an Isogenic Microphysiological Model of the Neurovascular Unit. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2101785. [PMID: 34174140 DOI: 10.1002/smll.202101785] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/21/2021] [Indexed: 05/20/2023]
Abstract
Microphysiological systems mimic the in vivo cellular ensemble and microenvironment with the goal of providing more human-like models for biopharmaceutical research. In this study, the first such model of the blood-brain barrier (BBB-on-chip) featuring both isogenic human induced pluripotent stem cell (hiPSC)-derived cells and continuous barrier integrity monitoring with <2 min temporal resolution is reported. Its capabilities are showcased in the first microphysiological study of nitrosative stress and antioxidant prophylaxis. Relying on off-stoichiometry thiol-ene-epoxy (OSTE+) for fabrication greatly facilitates assembly and sensor integration compared to the prevalent polydimethylsiloxane devices. The integrated cell-substrate endothelial resistance monitoring allows for capturing the formation and breakdown of the BBB model, which consists of cocultured hiPSC-derived endothelial-like and astrocyte-like cells. Clear cellular disruption is observed when exposing the BBB-on-chip to the nitrosative stressor linsidomine, and the barrier permeability and barrier-protective effects of the antioxidant N-acetylcysteine amide are reported. Using metabolomic network analysis reveals further drug-induced changes consistent with prior literature regarding, e.g., cysteine and glutathione involvement. A model like this opens new possibilities for drug screening studies and personalized medicine, relying solely on isogenic human-derived cells and providing high-resolution temporal readouts that can help in pharmacodynamic studies.
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Affiliation(s)
- Isabelle Matthiesen
- Division of Micro- and Nanosystems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, 100 44, Sweden
| | - Dimitrios Voulgaris
- Division of Micro- and Nanosystems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, 100 44, Sweden
- AIMES, Center for Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Solnavägen 9/B8, Solna, 171 65, Sweden
| | - Polyxeni Nikolakopoulou
- AIMES, Center for Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Solnavägen 9/B8, Solna, 171 65, Sweden
| | - Thomas E Winkler
- Division of Micro- and Nanosystems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, 100 44, Sweden
| | - Anna Herland
- Division of Micro- and Nanosystems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, 100 44, Sweden
- AIMES, Center for Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Solnavägen 9/B8, Solna, 171 65, Sweden
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12
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Liu Z, Kompella UB, Chauhan A. Gold nanoparticle synthesis in contact lenses for drug-less ocular cystinosis treatment. Eur J Pharm Biopharm 2021; 165:271-278. [PMID: 34044109 DOI: 10.1016/j.ejpb.2021.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/21/2021] [Accepted: 05/19/2021] [Indexed: 11/19/2022]
Abstract
PURPOSE To develop gold nanoparticles-loaded contact lens ("GoldinLens") to bind a significant mass of cystine on the surface of the gold nanoparticles (GNPs) for cystinosis treatment due to the reaction between cystine and gold. METHODS The GoldinLens was manufactured by synthesizing GNPs inside the preformed contact lens matrix by first loading the lenses (Moist and TrueEye) with gold precursor followed by reduction (with sodium borohydride or trisodium citrate) to gold atoms, which nucleated to GNPs inside the polymeric matrix. The lenses were characterized by SEM, XRD, UV-Vis spectroscopy and mass of GNPs loaded in the lens was determined by direct measurement of mass. Manufactured lenses were soaked in cystine solution for cystine uptake in vitro. RESULTS Results show that gold loading in the contact lens increases linearly with gold precursor concentration and number of repetitions of the manufacturing process. The stronger reducing agent sodium borohydride resulted in higher gold loading, with the loading being higher in the Moist lenses due to higher diffusivity of the reducing agent into the lens. However, GNPs were smaller in size and relatively monodispersed in TruEye GoldinLens, resulting in higher cystine uptake of 47 μg/lens over 24 h (vs. 33 μg/lens for Moist GoldinLens). However, the rate of this uptake was higher for Moist GoldiLens (8.25 vs. 2.35 μg/h), with the maximum uptake occurring in one hour (vs. five hours). CONCLUSION A method for manufacturing GoldinLens, wherein small gold nanoparticles are trapped in contact lenses, has been developed for drugless cystinosis treatment. The lenses withdraw cystine molecules from the surrounding milieu, with the TrueEye GoldinLens being superior for the extent of, while Moist GoldinLens is superior for rate of cystine removal. GoldinLenses of this study can be used for drugless cystine removal cystinosis treatment with one- or five-hour wear at a time.
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Affiliation(s)
- Zhen Liu
- Department of Chemical and Biological Engineering, Colorado School of Mines, CO 80401, USA.
| | - Uday B Kompella
- Department of Pharmaceutical Science, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Anuj Chauhan
- Department of Chemical and Biological Engineering, Colorado School of Mines, CO 80401, USA.
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13
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López-Cano JJ, González-Cela-Casamayor MA, Andrés-Guerrero V, Herrero-Vanrell R, Molina-Martínez IT. Liposomes as vehicles for topical ophthalmic drug delivery and ocular surface protection. Expert Opin Drug Deliv 2021; 18:819-847. [PMID: 33412914 DOI: 10.1080/17425247.2021.1872542] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: The development of ophthalmic formulations able to deliver hydrophilic and hydrophobic drugs to the inner structures of the eye and restore the preocular tear film has been a leading topic of discussion over the last few years. In this sense, liposomes represent a suitable strategy to achieve these objectives in ocular drug delivery.Areas covered: Knowledge of the different physiological and anatomical eye structures, and specially the ocular surface are critical to better understanding and comprehending the characteristics required for the development of topical ophthalmic liposomal formulations. In this review, several features of liposomes are discussed such as the main materials used for their fabrication, basic structure and preparation methods, from already established to novel techniques, allowing the control and design of special characteristics. Besides, physicochemical properties, purification processes and strategies to overcome delivery or encapsulation challenges are also presented. Expert opinion: Regarding ocular drug delivery of liposomes, there are some features that can be redesigned. Specific biocompatible and biodegradable materials presenting therapeutic properties, such as lipidic compounds or polymers significantly change the way of tackling ophthalmic diseases. Besides, liposomes entail an effective, safe and versatile strategy for the treatment of diseases in the clinical practice.
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Affiliation(s)
- José Javier López-Cano
- Department of Pharmaceutics and Food Technology, Complutense University, Madrid, Spain.,Ocular Pathology National Net (OFTARED) of the Institute of Health Carlos III, Health Research Institute of the San Carlos Clinical Hospital (Idissc), Madrid Spain
| | - Miriam Ana González-Cela-Casamayor
- Department of Pharmaceutics and Food Technology, Complutense University, Madrid, Spain.,Ocular Pathology National Net (OFTARED) of the Institute of Health Carlos III, Health Research Institute of the San Carlos Clinical Hospital (Idissc), Madrid Spain
| | - Vanessa Andrés-Guerrero
- Department of Pharmaceutics and Food Technology, Complutense University, Madrid, Spain.,Ocular Pathology National Net (OFTARED) of the Institute of Health Carlos III, Health Research Institute of the San Carlos Clinical Hospital (Idissc), Madrid Spain
| | - Rocío Herrero-Vanrell
- Department of Pharmaceutics and Food Technology, Complutense University, Madrid, Spain.,Ocular Pathology National Net (OFTARED) of the Institute of Health Carlos III, Health Research Institute of the San Carlos Clinical Hospital (Idissc), Madrid Spain
| | - Irene Teresa Molina-Martínez
- Department of Pharmaceutics and Food Technology, Complutense University, Madrid, Spain.,Ocular Pathology National Net (OFTARED) of the Institute of Health Carlos III, Health Research Institute of the San Carlos Clinical Hospital (Idissc), Madrid Spain
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14
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Rodrigues FSC, Campos A, Martins J, Ambrósio AF, Campos EJ. Emerging Trends in Nanomedicine for Improving Ocular Drug Delivery: Light-Responsive Nanoparticles, Mesoporous Silica Nanoparticles, and Contact Lenses. ACS Biomater Sci Eng 2020; 6:6587-6597. [PMID: 33320633 DOI: 10.1021/acsbiomaterials.0c01347] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Vision is the most dominant of our senses, and it is crucial in every stage of our lives. Ocular diseases, regardless of whether they cause vision impairment or not, lead to personal and financial hardships. The anatomy and physiology of the eye strongly limit the efficacy of current ocular drug delivery strategies. Nanotechnology has been the ground for the development of powerful strategies in several fields, namely in medicine. This review highlights emerging nanotechnology-based solutions for improving ocular drug delivery and thus the bioavailability and efficacy of drugs. We focus our review on ambitious but promising approaches currently emerging to leverage the efficacy of nanoparticle-based systems in ocular therapy: (i) light-responsive nanoparticles, which enable spatiotemporal control of drug release; (ii) mesoporous silica nanoparticles, which offer high surface area-to-volume ratio, simple surface modification, good biocompatibility, and improved bioavailability; and (iii) contact lenses, which serve as a compliant method of nanoparticles use and as drug delivery systems for the treatment of ocular diseases.
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Affiliation(s)
- Flávia S C Rodrigues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal
| | - António Campos
- Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal.,Department of Ophthalmology, Centro Hospitalar Leiria E.P.E., 2410-197 Leiria, Portugal.,ciTechCare, Center for Innovative Care and Health Technology, Polytechnic Institute of Leiria, 2410-541 Leiria, Portugal
| | - João Martins
- Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal.,Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal.,Institute of Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - António Francisco Ambrósio
- Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - Elisa J Campos
- Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, 3000-548 Coimbra, Portugal.,Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal.,Clinical Academic Center of Coimbra (CACC), 3004-561 Coimbra, Portugal.,Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
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15
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Kesavan K, Mohan P, Gautam N, Sheffield VC. Topical Ocular Delivery of Nanocarriers: A Feasible Choice for Glaucoma Management. Curr Pharm Des 2020; 26:5518-5532. [PMID: 32938345 DOI: 10.2174/1381612826666200916145609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/17/2020] [Indexed: 11/22/2022]
Abstract
Topical ocular delivery is an acceptable and familiar approach for the treatment of common ocular diseases. Novel strategies for the treatment of inherited eye diseases include new pharmacologic agents, gene therapy and genome editing, which lead to the expansion of new management options for eye disorders. The topical ocular delivery of nanocarriers is a technique, which has the potential to facilitate novel treatments. Nanocarrier- based strategies have proven effective for site-targeted delivery. This review summarizes recent development in the area of topical delivery of different nanocarriers (Polymer, Vesicular and dispersed systems) for the management of glaucoma, a group of ocular disorders characterized by progressive and accelerated degeneration of the axons of retinal ganglion cells, which make up the optic nerve. Unique cellular targets for glaucoma treatment, primarily the trabecular meshwork of the anterior segment of the eye, make glaucoma facilitated by the use of nanocarriers an ideal disorder for novel molecular therapies.
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Affiliation(s)
- Karthikeyan Kesavan
- Department of Pharmaceutics, SLT Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, C.G. 495009, India
| | - Parasuraman Mohan
- Department of Pharmaceutics, SLT Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, C.G. 495009, India
| | - Nivedita Gautam
- Department of Pharmaceutics, SLT Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, C.G. 495009, India
| | - Val C Sheffield
- Department of Pediatrics, Division of Medical Genetics and Genomics, Carver College of Medicine, University of Iowa, IA, 52242, United States
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16
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Use of biomaterials for sustained delivery of anti-VEGF to treat retinal diseases. Eye (Lond) 2020; 34:1341-1356. [PMID: 32001821 PMCID: PMC7376230 DOI: 10.1038/s41433-020-0770-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/27/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022] Open
Abstract
Anti-vascular endothelial growth factors (anti-VEGF) have become the most common treatment modality for many retinal diseases. These include neovascular age-related macular degeneration (n-AMD), proliferative diabetic retinopathy (PDR) and retinal vein occlusions (RVO). However, these drugs are administered via intravitreal injections that are associated with sight-threatening complications. The most feared of these complications is endophthalmitis, a severe infection of the eye with extremely poor visual outcomes. Patients with retinal diseases typically have to undergo multiple injections before achieving the desired therapeutic effect. Each injection incurs the risk of the sight-threatening complications. As such, there has been great interest in developing sustained delivery platforms for anti-VEGF agents to the posterior segment of the eye. In recent years, there have been various strategies that have been conceptualised. These include non-biodegradable implants, nano-formulations and hydrogels. In this review, the barriers of drug delivery to the posterior segment of the eye will be explained. The characteristics of an ideal sustained delivery platform will then be discussed. Finally, the current available strategies will be analysed with the above-mentioned characteristics in mind to determine the advantages and disadvantages of each sustained drug delivery modality. Through the above, this review attempts to provide an overview of the sustained delivery platforms in their various phases of development.
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17
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Erimban S, Daschakraborty S. Translocation of a hydroxyl functionalized carbon dot across a lipid bilayer: an all-atom molecular dynamics simulation study. Phys Chem Chem Phys 2020; 22:6335-6350. [DOI: 10.1039/c9cp05999g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Passive permeation of CD across lipid bilayer is almost impossible. Forced permeation results membrane rupture.
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Affiliation(s)
- Shakkira Erimban
- Department of Chemistry
- Indian Institute of Technology Patna
- Bihar 801106
- India
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18
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Cegielska O, Sajkiewicz P. Targeted Drug Delivery Systems for the Treatment of Glaucoma: Most Advanced Systems Review. Polymers (Basel) 2019; 11:E1742. [PMID: 31652975 PMCID: PMC6918324 DOI: 10.3390/polym11111742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 11/17/2022] Open
Abstract
Each year, new glaucoma drug delivery systems are developed. Due to the chronic nature of the disease, it requires the inconvenient daily administration of medications. As a result of their elution from the eye surface and penetration to the bloodstream through undesired permeation routes, the bioavailability of active compounds is low, and systemic side effects occur. Despite numerous publications on glaucoma drug carriers of controlled drug release kinetics, only part of them consider drug permeation routes and, thus, carriers' location, as an important factor affecting drug delivery. In this paper, we try to demonstrate the importance of the delivery proximal to glaucoma drug targets. The targeted delivery can significantly improve drug bioavailability, reduce side effects, and increase patients' compliance compared to both commercial and scientifically developed formulations that can spread over the eye surface or stay in contact with conjunctival sac. We present a selection of glaucoma drug carriers intended to be placed on cornea or injected into the aqueous humor and that have been made by advanced materials using hi-tech forming methods, allowing for effective and convenient sustained antiglaucoma drug delivery.
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Affiliation(s)
- Olga Cegielska
- Laboratory of Polymers and Biomaterials, Institute of Fundamental Technological Research Polish Academy of Sciences, Pawińskiego 5b, 02-106 Warsaw, Poland.
| | - Paweł Sajkiewicz
- Laboratory of Polymers and Biomaterials, Institute of Fundamental Technological Research Polish Academy of Sciences, Pawińskiego 5b, 02-106 Warsaw, Poland.
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19
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Moiseev RV, Morrison PWJ, Steele F, Khutoryanskiy VV. Penetration Enhancers in Ocular Drug Delivery. Pharmaceutics 2019; 11:E321. [PMID: 31324063 PMCID: PMC6681039 DOI: 10.3390/pharmaceutics11070321] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/01/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022] Open
Abstract
There are more than 100 recognized disorders of the eye. This makes the development of advanced ocular formulations an important topic in pharmaceutical science. One of the ways to improve drug delivery to the eye is the use of penetration enhancers. These are defined as compounds capable of enhancing drug permeability across ocular membranes. This review paper provides an overview of anatomical and physiological features of the eye and discusses some common ophthalmological conditions and permeability of ocular membranes. The review also presents the analysis of literature on the use of penetration-enhancing compounds (cyclodextrins, chelating agents, crown ethers, bile acids and bile salts, cell-penetrating peptides, and other amphiphilic compounds) in ocular drug delivery, describing their properties and modes of action.
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Affiliation(s)
- Roman V Moiseev
- Reading School of Pharmacy, University of Reading, Whiteknights, P.O. Box 224, Reading RG66AD, UK
| | - Peter W J Morrison
- Reading School of Pharmacy, University of Reading, Whiteknights, P.O. Box 224, Reading RG66AD, UK
| | - Fraser Steele
- MC2 Therapeutics, James House, Emlyn Lane, Leatherhead KT22 7EP, UK
| | - Vitaliy V Khutoryanskiy
- Reading School of Pharmacy, University of Reading, Whiteknights, P.O. Box 224, Reading RG66AD, UK.
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20
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Sapino S, Chirio D, Peira E, Abellán Rubio E, Brunella V, Jadhav SA, Chindamo G, Gallarate M. Ocular Drug Delivery: A Special Focus on the Thermosensitive Approach. NANOMATERIALS 2019; 9:nano9060884. [PMID: 31207951 PMCID: PMC6630567 DOI: 10.3390/nano9060884] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/05/2019] [Accepted: 06/10/2019] [Indexed: 12/16/2022]
Abstract
The bioavailability of ophthalmic therapeutics is reduced because of the presence of physiological barriers whose primary function is to hinder the entry of exogenous agents, therefore also decreasing the bioavailability of locally administered drugs. Consequently, repeated ocular administrations are required. Hence, the development of drug delivery systems that ensure suitable drug concentration for prolonged times in different ocular tissues is certainly of great importance. This objective can be partially achieved using thermosensitive drug delivery systems that, owing to their ability of changing their state in response to temperature variations, from room to body temperature, may increase drug bioavailability. In the case of topical instillation, in situ forming gels increase pre-corneal drug residence time as a consequence of their enhanced adhesion to the corneal surface. Otherwise, in the case of intraocular and periocular, i.e., subconjunctival, retrobulbar, peribulbar administration, among others, they have the undoubted advantage of being easily injectable and, owing to their sudden thickening at body temperature, have the ability to form an in situ drug reservoir. As a result, the frequency of administration can be reduced, also favoring the patient’s adhesion to therapy. In the main section of this review, we discuss some of the most common treatment options for ocular diseases, with a special focus on posterior segment treatments, and summarize the most recent improvement deriving from thermosensitive drug delivery strategies. Aside from this, an additional section describes the most widespread in vitro models employed to evaluate the functionality of novel ophthalmic drug delivery systems.
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Affiliation(s)
- Simona Sapino
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy.
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
| | - Daniela Chirio
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy.
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
| | - Elena Peira
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy.
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
| | | | - Valentina Brunella
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
- Department of Chemistry, University of Turin, 10125 Turin, Italy.
| | - Sushilkumar A Jadhav
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
- School of Nanoscience and Technology, Shivaji University Kolhapur, Maharashtra 416004, India.
| | - Giulia Chindamo
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy.
| | - Marina Gallarate
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy.
- NIS Research Centre, University of Turin, 10125 Turin, Italy.
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21
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Ocular biopharmaceutics: impact of modeling and simulation on topical ophthalmic formulation development. Drug Discov Today 2019; 24:1587-1597. [PMID: 30959112 DOI: 10.1016/j.drudis.2019.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/07/2019] [Accepted: 04/02/2019] [Indexed: 12/12/2022]
Abstract
The estimation of ocular pharmacokinetics (PK) in various eye tissues is limited because of sampling challenges. Computational modeling and simulation (M&S) tools underpinning the elucidation of drug access routes and prediction of ocular exposure are essential for the mechanistic assessment of biopharmaceutics in the eye. Therefore, theoretical and experimental evaluation of ocular absorption and transit models is necessary. Biopharmaceutical parameter sensitivity analysis based on permeability and drug dose illustrates utility in ocular drug delivery assessment, which could have innovative and cost-saving impacts on ophthalmic product development and therapeutic bioequivalence (BE) evaluations.
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22
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Almekkawy M, Chen J, Ellis MD, Haemmerich D, Holmes DR, Linte CA, Panescu D, Pearce J, Prakash P, Zderic V. Therapeutic Systems and Technologies: State-of-the-Art Applications, Opportunities, and Challenges. IEEE Rev Biomed Eng 2019; 13:325-339. [PMID: 30951478 PMCID: PMC7341980 DOI: 10.1109/rbme.2019.2908940] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this review, we present current state-of-the-art developments and challenges in the areas of thermal therapy, ultrasound tomography, image-guided therapies, ocular drug delivery, and robotic devices in neurorehabilitation. Additionally, intellectual property and regulatory aspects pertaining to therapeutic systems and technologies are addressed.
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23
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Sharma M, Deohra A, Reddy KR, Sadhu V. Biocompatible in-situ gelling polymer hydrogels for treating ocular infection. J Microbiol Methods 2019. [DOI: 10.1016/bs.mim.2019.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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24
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Drug delivery to the eye anterior chamber by intraocular lenses: An in vivo concentration estimation model. Eur J Pharm Biopharm 2018; 133:63-69. [PMID: 30292794 DOI: 10.1016/j.ejpb.2018.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 11/22/2022]
Abstract
Drug loaded intraocular lenses have been proposed as an alternative to the conventional post-cataract removal prophylaxis through topical drug administration, since the drug or combination of drugs released from the lenses are delivered directly to the target site. In this work, a mathematical model to estimate the concentration of drug released from such lenses in the eye aqueous humor was developed. To attain these estimated concentration profiles, partition and effective diffusivity coefficients for the specific lens material were obtained from standard in vitro release experiments. The model was validated by comparing the predicted aqueous humor concentrations with those obtained in in vivo studies where hydrophilic acrylic intraocular lens loaded with an antibiotic (moxifloxacin) were implanted in rabbits. Subsequently, other partition and effective diffusivity values were determined for levofloxacin, diclofenac and ketorolac in the same hydrophilic acrylic and in a second material, a silicone hydrogel. Predicted drug concentrations in the aqueous humor allowed an initial screening and evaluation of the most promising system for post-cataract removal prophylaxis, with the hydrophilic acrylic material presenting promising results, especially for moxifloxacin and diclofenac controlled release.
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25
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Srinivas SP, Goyal A, Talele DP, Mahadik S, Sudhir RR, Murthy PP, Ranganath S, Kompella UB, Padmanabhan P. Corneal epithelial permeability to fluorescein in humans by a multi-drop method. PLoS One 2018; 13:e0198831. [PMID: 29920519 PMCID: PMC6007839 DOI: 10.1371/journal.pone.0198831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/26/2018] [Indexed: 01/21/2023] Open
Abstract
Purpose The permeability of the corneal epithelium to fluorescein Pdc is an indicator of the health of the ocular surface. It can be measured in a clinical setting by determining the accumulation of fluorescein in the stroma following administration of the dye on the ocular surface. Here we demonstrate a new multi-drop method for the measurement of Pdc by a spot fluorometer. Methods Twenty-nine healthy participants were recruited for this study. First, a probe-drop of fluorescein (0.35%, 2 μL) was instilled on the conjunctiva. The clearance of the dye from the tears was immediately measured using the fluorometer. Following this, two loading drops (2%; 6 μL each) were administered 10 min apart. Fifteen minutes later, the ocular surface was washed and fluorescence from the stroma Fs was measured. Permeability was calculated using Pdc = (Q x Fs)/ (2 x AUC), where Q is the stromal thickness and AUC is the area under the fluorescence vs. time curve for the loading drops. Results After the probe drop, the tear fluorescence followed an exponential decay (elimination rate constant; kd = 0.41 ± 0.28 per min; 49 eyes of 29 subjects), but the increase in Fs was negligible. However, after the loading drops, the measured Fs was ~ 20-fold higher than the autofluorescence and could be recorded at a high signal to noise ratio (SNR > 40). The intra-subject variability of kd was insignificant. Since fluorescein undergoes concentration quenching at > 0.5%, the value of AUC for the loading drops was estimated by scaling the AUC of the probe drop. The calculated Pdc was 0.54 ± 0.54 nm/sec (n = 49). A Monte Carlo simulation of the model for the multi-drop protocol confirmed the robustness of the estimated Pdc. Conclusions The new multi-drop method can be used in place of the single-drop approach. It can overcome a lack of sensitivity in fluorometers of high axial resolution. The Pdc estimated by the multi-drop method is ~ 11-fold higher than previously reported but closer to the value reported for other drugs with equivalent octanol/water partition coefficient.
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Affiliation(s)
- Sangly P. Srinivas
- School of Optometry, Indiana University, Bloomington, Indiana, United States of America
- * E-mail:
| | - Arushi Goyal
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | - Deepti P. Talele
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | - Sanjay Mahadik
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | | | - P. Pavani Murthy
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
| | - Sudhir Ranganath
- Department of Chemical Engineering, Siddaganga Institute of Technology, Tumkur, India
| | - Uday B. Kompella
- Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Prema Padmanabhan
- Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India
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26
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Controlled delivery of pirfenidone through vitamin E-loaded contact lens ameliorates corneal inflammation. Drug Deliv Transl Res 2018; 8:1114-1126. [DOI: 10.1007/s13346-018-0541-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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27
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Bertens CJ, Gijs M, van den Biggelaar FJ, Nuijts RM. Topical drug delivery devices: A review. Exp Eye Res 2018; 168:149-160. [DOI: 10.1016/j.exer.2018.01.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 12/08/2017] [Accepted: 01/11/2018] [Indexed: 12/22/2022]
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28
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Huang D, Chen YS, Rupenthal ID. Overcoming ocular drug delivery barriers through the use of physical forces. Adv Drug Deliv Rev 2018; 126:96-112. [PMID: 28916492 DOI: 10.1016/j.addr.2017.09.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/30/2017] [Accepted: 09/08/2017] [Indexed: 12/25/2022]
Abstract
Overcoming the physiological barriers in the eye remains a key obstacle in the field of ocular drug delivery. While ocular barriers naturally have a protective function, they also limit drug entry into the eye. Various pharmaceutical strategies, such as novel formulations and physical force-based techniques, have been investigated to weaken these barriers and transport therapeutic agents effectively to both the anterior and the posterior segments of the eye. This review summarizes and discusses the recent research progress in the field of ocular drug delivery with a focus on the application of physical methods, including electrical fields, sonophoresis, and microneedles, which can enhance penetration efficiency by transiently disrupting the ocular barriers in a minimally or non-invasive manner.
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29
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Suwannoi P, Chomnawang M, Sarisuta N, Reichl S, Müller-Goymann CC. Development of Acyclovir-Loaded Albumin Nanoparticles and Improvement of Acyclovir Permeation Across Human Corneal Epithelial T Cells. J Ocul Pharmacol Ther 2017; 33:743-752. [DOI: 10.1089/jop.2017.0057] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Panita Suwannoi
- Department of Manufacturing Pharmacy, Mahidol University, Bangkok, Thailand
| | - Mullika Chomnawang
- Department of Microbiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Narong Sarisuta
- Department of Manufacturing Pharmacy, Mahidol University, Bangkok, Thailand
- Division of Pharmaceutical Sciences, Faculty of Pharmacy, Thammasat University, Pathumthani, Thailand
| | - Stephan Reichl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany
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30
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Pak J, Chen ZJ, Sun K, Przekwas A, Walenga R, Fan J. Computational modeling of drug transport across the in vitro cornea. Comput Biol Med 2017; 92:139-146. [PMID: 29175100 DOI: 10.1016/j.compbiomed.2017.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/09/2017] [Accepted: 11/12/2017] [Indexed: 12/12/2022]
Abstract
A novel quasi-3D (Q3D) modeling approach was developed to model networks of one dimensional structures like tubes and vessels common in human anatomy such as vascular and lymphatic systems, neural networks, and respiratory airways. Instead of a branching network of the same tissue type, this approach was extended to model an interconnected stack of different corneal tissue layers with membrane junction conditions assigned between the tissues. The multi-laminate structure of the cornea presents a unique barrier design and opportunity for investigation using Q3D modeling. A Q3D model of an in vitro rabbit cornea was created to simulate the drug transport across the cornea, accounting for transcellular and paracellular pathways of passive and convective drug transport as well as physicochemistry of lipophilic partitioning and protein binding. Lipophilic Rhodamine B and hydrophilic fluorescein were used as drug analogs. The model predictions for both hydrophilic and lipophilic tracers were able to match the experimental measurements along with the sharp discontinuities at the epithelium-stroma and stroma-endothelium interfaces. This new modeling approach was successfully applied towards pharmacokinetic modeling for use in topical ophthalmic drug design.
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Affiliation(s)
- Joseph Pak
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Z J Chen
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Kay Sun
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA.
| | - Andrzej Przekwas
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Ross Walenga
- Office of Generic Drugs, Food and Drug Administration, Silver Spring, MD, USA
| | - Jianghong Fan
- Office of Generic Drugs, Food and Drug Administration, Silver Spring, MD, USA
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Jian HJ, Wu RS, Lin TY, Li YJ, Lin HJ, Harroun SG, Lai JY, Huang CC. Super-Cationic Carbon Quantum Dots Synthesized from Spermidine as an Eye Drop Formulation for Topical Treatment of Bacterial Keratitis. ACS NANO 2017; 11:6703-6716. [PMID: 28677399 DOI: 10.1021/acsnano.7b01023] [Citation(s) in RCA: 244] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We have developed a one-step method to synthesize carbon quantum dots (CQDPAs) from biogenic polyamines (PAs) as an antibacterial agent for topical treatment of bacterial keratitis (BK). CQDs synthesized by direct pyrolysis of spermidine (Spd) powder through a simple dry heating treatment exhibit a solubility and yield much higher than those from putrescine and spermine. We demonstrate that CQDs obtained from Spds (CQDSpds) possess effective antibacterial activities against non-multidrug-resistant Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica serovar Enteritidis bacteria and also against the multidrug-resistant bacteria, methicillin-resistant S. aureus. The minimal inhibitory concentration (MIC) of CQDSpds is ∼2500-fold lower than that of spermidine alone, demonstrating their strong antibacterial capabilities. Investigation of the possible mechanisms behind the antibacterial activities of the as-synthesized CQDSpds indicates that the super-cationic CQDSpds with small size (diameter ca. 6 nm) and highly positive charge (ζ-potential ca. +45 mV) cause severe disruption of the bacterial membrane. In vitro cytotoxicity, hemolysis, hemagglutination, genotoxicity, and oxidative stress and in vivo morphologic and physiologic cornea change evaluations show the good biocompatibility of CQDSpds. Furthermore, topical ocular administration of CQDSpds can induce the opening of the tight junction of corneal epithelial cells, thereby leading to great antibacterial treatment of S. aureus-induced BK in rabbits. Our results suggest that CQDSpds are a promising antibacterial candidate for clinical applications in treating eye-related bacterial infections and even persistent bacteria-induced infections.
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Affiliation(s)
- Hong-Jyuan Jian
- Institute of Biochemical and Biomedical Engineering, Chang Gung University , Taoyuan 33302, Taiwan
| | - Ren-Siang Wu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University , Keelung 20224, Taiwan
| | - Tzu-Yu Lin
- Institute of Biochemical and Biomedical Engineering, Chang Gung University , Taoyuan 33302, Taiwan
| | - Yu-Jia Li
- Institute of Biochemical and Biomedical Engineering, Chang Gung University , Taoyuan 33302, Taiwan
| | - Han-Jia Lin
- Department of Bioscience and Biotechnology, National Taiwan Ocean University , Keelung 20224, Taiwan
| | - Scott G Harroun
- Department of Chemistry, Université de Montréal , Montréal, Québec H3C 3J7, Canada
| | - Jui-Yang Lai
- Institute of Biochemical and Biomedical Engineering, Chang Gung University , Taoyuan 33302, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital , Taoyuan 33305, Taiwan
- Department of Materials Engineering, Ming Chi University of Technology , New Taipei City 24301, Taiwan
| | - Chih-Ching Huang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University , Keelung 20224, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University , Keelung 20224, Taiwan
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University , Kaohsiung 80708, Taiwan
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Chiang B, Wang K, Ethier CR, Prausnitz MR. Clearance Kinetics and Clearance Routes of Molecules From the Suprachoroidal Space After Microneedle Injection. Invest Ophthalmol Vis Sci 2017; 58:545-554. [PMID: 28125841 PMCID: PMC5283080 DOI: 10.1167/iovs.16-20679] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose To determine clearance kinetics and routes of clearance of molecules from the suprachoroidal space (SCS) of live New Zealand White rabbits. Methods Suprachoroidal space collapse rate and pressure changes after microneedle injection into SCS were determined. Fluorescent fundus images were acquired to determine clearance rates of molecules ranging in size from 332 Da to 2 MDa. Microneedle injections of fluorescein were performed, and samples were taken from various sites over time to determine amount of fluorescein exiting the eye. Clearance transport was modeled theoretically and compared with experimental data. Results After injection, pressures in SCS and vitreous humor spiked and returned to baseline within 20 minutes; there was no difference between these two pressures. Suprachoroidal space collapse occurred within 40 minutes. One hour after fluorescein injection, 46% of fluorescein was still present in the eye, 15% had transported across sclera, 6% had been cleared by choroidal vasculature, and 4% had exited via leakage pathways. Characteristic clearance time increased in proportion with molecular radius, but total clearance of 2 MDa FITC-dextran was significantly slower (21 days) than smaller molecules. These data generally agreed with predictions from a theoretical model of molecular transport. Conclusions Guided by experimental data in the context of model predictions, molecular clearance from SCS occurred in three regimes: (1) on a time scale of approximately 10 minutes, fluid and molecules exited SCS by diffusion into sclera and choroid, and by pressure-driven reflux via transscleral leakage sites; (2) in approximately 1 hour, molecules cleared from choroid by blood flow; and (3) in 1 to 10 hours, molecules cleared from sclera by diffusion and convection.
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Affiliation(s)
- Bryce Chiang
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Ke Wang
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Mark R Prausnitz
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, Georgia, United States 2School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
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Hariharan P, Nabili M, Guan A, Zderic V, Myers M. Model for Porosity Changes Occurring during Ultrasound-Enhanced Transcorneal Drug Delivery. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1223-1236. [PMID: 28335999 PMCID: PMC5768443 DOI: 10.1016/j.ultrasmedbio.2017.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 01/09/2017] [Accepted: 01/22/2017] [Indexed: 06/06/2023]
Abstract
Ultrasound-enhanced drug delivery through the cornea has considerable therapeutic potential. However, our understanding of how ultrasound enhances drug transport is poor, as is our ability to predict the increased level of transport for given ultrasound parameters. Described here is a computational model for quantifying changes in corneal porosity during ultrasound exposure. The model is calibrated through experiments involving sodium fluorescein transport through rabbit cornea. Validation was performed using nylon filters, for which the properties are known. It was found that exposure to 800-kHz ultrasound at an intensity 2 W/cm2 for 5 min increased the porosity of the epithelium by a factor of 5. The model can be useful for determining the extent to which ultrasound enhances the amount of drug transported through biological barriers, and the time at which a therapeutic dose is achieved at a given location, for different drugs and exposure strategies.
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Affiliation(s)
- Prasanna Hariharan
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Marjan Nabili
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Allan Guan
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Vesna Zderic
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Matthew Myers
- Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland, USA.
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Joseph M, Trinh HM, Cholkar K, Pal D, Mitra AK. Recent perspectives on the delivery of biologics to back of the eye. Expert Opin Drug Deliv 2017; 14:631-645. [PMID: 27573097 PMCID: PMC5570518 DOI: 10.1080/17425247.2016.1227783] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Biologics are generally macromolecules, large in size with poor stability in biological environments. Delivery of biologics to tissues at the back of the eye remains a challenge. To overcome these challenges and treat posterior ocular diseases, several novel approaches have been developed. Nanotechnology-based delivery systems, like drug encapsulation technology, macromolecule implants and gene delivery are under investigation. We provide an overview of emerging technologies for biologics delivery to back of the eye tissues. Moreover, new biologic drugs currently in clinical trials for ocular neovascular diseases have been discussed. Areas covered: Anatomy of the eye, posterior segment disease and diagnosis, barriers to biologic delivery, ocular pharmacokinetic, novel biologic delivery system Expert opinion: Anti-VEGF therapy represents a significant advance in developing biologics for the treatment of ocular neovascular diseases. Various strategies for biologic delivery to posterior ocular tissues are under development with some in early or late stages of clinical trials. Despite significant progress in the delivery of biologics, there is unmet need to develop sustained delivery of biologics with nearly zero-order release kinetics to the back of the eye tissues. In addition, elevated intraocular pressure associated with frequent intravitreal injections of macromolecules is another concern that needs to be addressed.
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Affiliation(s)
- Mary Joseph
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Hoang M. Trinh
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Kishore Cholkar
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
- RiconPharma LLC, 100 Ford Road, Suite 9, Denville, NJ, 07834 USA
| | - Dhananjay Pal
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
| | - Ashim K. Mitra
- Division of Pharmaceutical Sciences, School of Pharmacy, 5258 Health Science Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO, 64108 USA
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Simon L, Ospina J. The development of a peak-time criterion for designing controlled-release devices. Eur J Pharm Sci 2016; 91:64-73. [PMID: 27260085 DOI: 10.1016/j.ejps.2016.05.028] [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: 04/23/2016] [Revised: 05/20/2016] [Accepted: 05/29/2016] [Indexed: 11/25/2022]
Abstract
This work consists of estimating dynamic characteristics for topically-applied drugs when the magnitude of the flux increases to a maximum value, called peak flux, before declining to zero. This situation is typical of controlled-released systems with a finite donor or vehicle volume. Laplace transforms were applied to the governing equations and resulted in an expression for the flux in terms of the physical characteristics of the system. After approximating this function by a second-order model, three parameters of this reduced structure captured the essential features of the original process. Closed-form relationships were then developed for the peak flux and time-to-peak based on the empirical representation. Three case studies that involve mechanisms, such as diffusion, partitioning, dissolution and elimination, were selected to illustrate the procedure. The technique performed successfully as shown by the ability of the second-order flux to match the prediction of the original transport equations. A main advantage of the proposed method is that it does not require a solution of the original partial differential equations. Less accurate results were noted for longer lag times.
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Affiliation(s)
- Laurent Simon
- Otto H. York Department of Chemical, Biological and Pharmaceutical Engineering, New Jersey Institute of Technology, Newark, NJ 0702, USA
| | - Juan Ospina
- Logic and Computation Group, Physics Engineering Program, School of Sciences and Humanities, EAFIT University, Medellin, Colombia
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Cuvas Apan O, Ozer MA, Takir S, Apan A, Sengul D. Effect of topical administration of tramadol on corneal wound healing in rats. Int Ophthalmol 2016; 36:675-80. [PMID: 26820482 DOI: 10.1007/s10792-016-0184-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/19/2016] [Indexed: 12/17/2022]
Abstract
In this study, we aimed to investigate the effects of topical tramadol administration on corneal wound healing, and examine ophthalmic structures and intraocular pressure 7 days after tramadol administration. The experiments were conducted on eight male Wistar rats (250-300 g). After ophthalmic examination, epithelial cell layers in the central cornea were wounded. Rats received 30 μL of tramadol hydrochloride in one eye (Group Tramadol) and the same volume of vehicle in the other (Group Control) every 12 h for 7 days. Both eyes were stained with fluorescein dye, photographed, and wound area was calculated every 8 h until complete healing was observed. Eye blink frequency and corneal reflex tests were measured before and after drug administrations. After 7 days, slit lamp biomicroscopy, fundoscopy, Goldmann applanation tonometry, and histological evaluation were performed. There was no difference in the corneal wound healing rates between the tramadol and control groups. Reduction in wound area over time was also similar; group-time interaction was insignificant (F = 738.911; p = 0.225). Tramadol application resulted in blinking and blepharospasm for 30 s, but vehicle did not. Corneal reflex was intact and eye blink frequency test results were similar in all measurement times in both groups. Slit lamp biomicroscopy, fundoscopy, and intraocular pressures were within normal range. Corneal cells appeared unaffected by the repeated doses of tramadol for 7 days. Topical tramadol application on the cornea did not cause any side effect, except for initial temporary blinking and blepharospasm. Corneal wound healing was not affected, either.
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Affiliation(s)
- Ozgun Cuvas Apan
- Department of Anesthesiology and Intensive Care Medicine, Giresun University Medical Faculty, Nizamiye Yerleskesi, Orhan Yılmaz Caddesi, Mumcular Sokak No:1, Merkez, 28200, Giresun, Turkey.
| | - Murat Atabey Ozer
- Department of Ophthalmology, Giresun University Medical Faculty, Giresun, Turkey
| | - Selcuk Takir
- Department of Clinical Pharmacology, Giresun University Medical Faculty, Giresun, Turkey
| | - Alparslan Apan
- Department of Anesthesiology and Intensive Care Medicine, Giresun University Medical Faculty, Nizamiye Yerleskesi, Orhan Yılmaz Caddesi, Mumcular Sokak No:1, Merkez, 28200, Giresun, Turkey
| | - Demet Sengul
- Department of Pathology, Giresun University Medical Faculty, Giresun, Turkey
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Kim YC, Chiang B, Wu X, Prausnitz MR. Ocular delivery of macromolecules. J Control Release 2014; 190:172-81. [PMID: 24998941 PMCID: PMC4142116 DOI: 10.1016/j.jconrel.2014.06.043] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 06/23/2014] [Indexed: 12/22/2022]
Abstract
Biopharmaceuticals are making increasing impact on medicine, including treatment of indications in the eye. Macromolecular drugs are typically given by physician-administered invasive delivery methods, because non-invasive ocular delivery methods, such as eye drops, and systemic delivery, have low bioavailability and/or poor ocular targeting. There is a need to improve delivery of biopharmaceuticals to enable less-invasive delivery routes, less-frequent dosing through controlled-release drug delivery and improved drug targeting within the eye to increase efficacy and reduce side effects. This review discusses the barriers to drug delivery via various ophthalmic routes of administration in the context of macromolecule delivery and discusses efforts to develop controlled-release systems for delivery of biopharmaceuticals to the eye. The growing number of macromolecular therapies in the eye needs improved drug delivery methods that increase drug efficacy, safety and patient compliance.
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Affiliation(s)
- Yoo Chun Kim
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Bryce Chiang
- Wallace Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Xianggen Wu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, China
| | - Mark R Prausnitz
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Wallace Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Sriram S, Gibson DJ, Robinson P, Pi L, Tuli S, Lewin AS, Schultz G. Assessment of anti-scarring therapies in ex vivo organ cultured rabbit corneas. Exp Eye Res 2014; 125:173-82. [PMID: 24971495 PMCID: PMC4496961 DOI: 10.1016/j.exer.2014.06.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 06/06/2014] [Accepted: 06/10/2014] [Indexed: 01/09/2023]
Abstract
The effects of a triple combination of siRNAs targeting key scarring genes were assessed using an ex vivo organ culture model of excimer ablated rabbit corneas. The central 6 mm diameter region of fresh rabbit globes was ablated to a depth of 155 microns with an excimer laser. Corneas were excised, cultured at the air-liquid interface in defined culture medium supplemented with transforming growth factor beta 1 (TGFB1), and treated with either 1% prednisolone acetate or with 22.5 μM cationic nanoparticles complexed with a triple combination of siRNAs (NP-siRNA) targeting TGFB1, TGFB Receptor (TGFBR2) and connective tissue growth factor (CTGF). Scar formation was measured using image analysis of digital images and levels of smooth muscle actin (SMA) were assessed in ablated region of corneas using qRT-PCR and immunostaining. Ex vivo cultured corneas developed intense haze-like scar in the wounded areas and levels of mRNAs for pro-fibrotic genes were significantly elevated 3-8 fold in wounded tissue compared to unablated corneas. Treatment with NP-siRNA or steroid significantly reduced quantitative haze levels by 55% and 68%, respectively, and reduced SMA mRNA and immunohistostaining. This ex vivo corneal culture system reproduced key molecular patterns of corneal scarring and haze formation generated in rabbits. Treatment with NP-siRNAs targeting key scarring genes or an anti-inflammatory steroid reduced corneal haze and SMA mRNA and protein.
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Affiliation(s)
- Sriniwas Sriram
- Schepens Eye Research Institute, Harvard Medical School, University of Florida, USA.
| | - Daniel J Gibson
- Institute for Wound Research, Department of Obstetrics and Gynecology, University of Florida, USA
| | | | - Liya Pi
- Department of Pediatrics, University of Florida, USA
| | - Sonal Tuli
- Department of Ophthalmology, University of Florida, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, USA
| | - Gregory Schultz
- Institute for Wound Research, Department of Obstetrics and Gynecology, University of Florida, USA
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Prediction of passive drug permeability across the blood-retinal barrier. Pharm Res 2014; 31:2297-311. [PMID: 24623477 DOI: 10.1007/s11095-014-1325-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/28/2014] [Indexed: 12/22/2022]
Abstract
PURPOSE The purpose of this study is to develop a computational model of the physical barrier function of the outer blood-retinal barrier (BRB), which is vital for normal retinal function. To our best knowledge no comprehensive models of BRB has been reported. METHODS The model construction is based on the three-layered structure of the BRB: retinal pigment epithelium (RPE), Bruch's membrane and choriocapillaris endothelium. Their permeabilities were calculated based on the physical theories and experimental material and permeability studies in the literature, which were used to describe diffusional hindrance in specific environments. RESULTS Our compartmental BRB model predicts permeabilities with magnitudes similar to the experimental values in the literature. However, due to the small number and varying experimental conditions there is a large variability in the available experimental data, rendering validation of the model difficult. The model suggests that the paracellular pathway of the RPE largely defines the total BRB permeability. CONCLUSIONS Our model is the first BRB model of its level and combines the present knowledge of the BRB barrier function. Furthermore, the model forms a platform for the future model development to be used for the design of new drugs and drug administration systems.
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Mohanty B, Mishra SK, Majumdar DK. Effect of formulation factors on in vitro transcorneal permeation of voriconazole from aqueous drops. J Adv Pharm Technol Res 2013; 4:210-6. [PMID: 24350052 PMCID: PMC3853698 DOI: 10.4103/2231-4040.121416] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The purpose of this research was to evaluate the effect the formulation factors on in vitro permeation of voriconazole through freshly isolated goat and sheep corneas. An increase in the pH of the drops from 4.0 to 8.0 resulted in significant (P < 0.05) increase drug permeation. Raising concentration of the drops from 0.05% to 0.2% (w/v) significantly, (P < 0.05) increased drug permeation, but decreased the percent permeation. Corneal transport of voriconazole is both pH and concentration dependent. Eye drops containing disodium edetate (ethylenediaminetetraacetic acid) alone or combination with benzalkonium chloride showed significantly (P < 0.05) higher permeation as compared with control formulation. Addition of beta-cyclodextrin to the formulation enhanced corneal permeation of voriconazole. Compared with control formulation, voriconazole 0.2% (w/v) drop containing viscosity modifier produced significant (P < 0.05) decrease in permeation. Most of the formulations showed higher zone of inhibition against Candida albicans.
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Affiliation(s)
- Biswaranjan Mohanty
- Department of Pharmaceutics, Seemanta Institute of Pharmaceutical Sciences, Jharpokharia, Mayurbhanj, Orissa, India
| | - Sagar Kumar Mishra
- Department of Pharmaceutical Sciences, Utkal University, Bhubaneswar, Orissa, India
| | - Dipak K Majumdar
- Department of Pharmaceutics, Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, New Delhi, India
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Moosa RM, Choonara YE, du Toit LC, Kumar P, Carmichael T, Tomar LK, Tyagi C, Pillay V. A review of topically administered mini-tablets for drug delivery to the anterior segment of the eye. ACTA ACUST UNITED AC 2013; 66:490-506. [PMID: 24635554 DOI: 10.1111/jphp.12131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 07/23/2013] [Indexed: 01/09/2023]
Abstract
OBJECTIVES The human eye is a unique and intricate structure which has made drug delivery to the eye a formidable undertaking. Anterior-segment eye diseases are ubiquitous, especially among elderly patients, and conventional eye drops, although a first-choice dosage form, are not always an efficient treatment option. The development of novel drug delivery systems for improved treatment is therefore imperative. KEY FINDINGS In an attempt to circumvent the obstacles presented by the structure of the eye, advanced systems such as ocular mini-tablets have been developed. In this review, a concerted effort has been made to provide a detailed overview of topically administered ocular mini-tablets and other solid devices for drug delivery to the anterior segment of the eye. These mini-tablets have been shown in vitro and in vivo to have significant advantages in comparison with liquid preparations. This is a step toward attaining better patient convenience and compliance, which are critical factors. SUMMARY Solid ophthalmic dosage forms have several advantages that can contribute to assisting with patient compliance and, ultimately, effective disease treatment. In addition to the challenges associated with topical ocular drug delivery, the shortcomings of conventional eye drops, advantages of mini-tablets, and improvements to date to these systems are discussed. The requirement for further advancements in the ocular field is also emphasized.
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Affiliation(s)
- Raeesa M Moosa
- Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Jung HJ, Chauhan A. Extended release of timolol from nanoparticle-loaded fornix insert for glaucoma therapy. J Ocul Pharmacol Ther 2012. [PMID: 23205896 DOI: 10.1089/jop.2012.0114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
We have developed a cylindrical insert that can be inserted in the fornix for extended release of glaucoma drug timolol. The insert is prepared by incorporating timolol-loaded nanoparticles into a poly hydroxyl ethyl methacrylate (p-HEMA) matrix. A 1-mm diameter, 7.5-mm long insert with 25% (w/w) particles can release timolol for about 10 days at an average rate of about 15 μg/day, which may be therapeutically effective. The increase in particle fraction increases drug loading, but also increases the release duration. The net effect of increasing the particle fraction is a significant increase in release duration, but a decrease in daily drug release rates, in the first few weeks. The release duration increases to about 1 and 3 months on increasing the particle fraction to 50% and 75%, respectively. The average daily release rates in the first 3 weeks are 15, 9, and 3 μg/day for the inserts with 50%, 75%, and 100% (w/w) particles, respectively. The mechanism of release is hydrolysis of the ester bond that links timolol to the propoxylated glyceryl triacrylate matrix, and thus the release profiles fit a first order reaction model. The water content of the inserts decreases from 31% to almost zero on increasing the particle loading from 25% to 100%. The rate constant for the hydrolysis decreases with an increase in particle loading in the insert most likely due to the reduction in the water content. The inserts can be packaged in wet conditions and stored in a refrigerator, but the inserts will exhibit a burst release caused by release of the drug from the particles into the p-HEMA matrix during the shelf life. Also, the magnitude of drug release after the initial burst is reduced due to the storage. The burst effect could potentially be avoided by packaging the inserts in a dry state, with hydration before insertion.
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Affiliation(s)
- Hyun Jung Jung
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
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Wilson* CG, Tan LE. Nanostructures Overcoming the Ocular Barrier: Physiological Considerations and Mechanistic Issues. NANOSTRUCTURED BIOMATERIALS FOR OVERCOMING BIOLOGICAL BARRIERS 2012. [DOI: 10.1039/9781849735292-00173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Quantitative and qualitative prediction of corneal permeability for drug-like compounds. Talanta 2011; 85:2686-94. [PMID: 21962703 DOI: 10.1016/j.talanta.2011.08.060] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/24/2011] [Accepted: 08/28/2011] [Indexed: 01/12/2023]
Abstract
A set of 69 drug-like compounds with corneal permeability was studied using quantitative and qualitative modeling techniques. Multiple linear regression (MLR) and multilayer perceptron neural network (MLP-NN) were used to develop quantitative relationships between the corneal permeability and seven molecular descriptors selected by stepwise MLR and sensitivity analysis methods. In order to evaluate the models, a leave many out cross-validation test was performed, which produced the statistic Q(2)=0.584 and SPRESS=0.378 for MLR and Q(2)=0.774 and SPRESS=0.087 for MLP-NN. The obtained results revealed the suitability of MLP-NN for the prediction of corneal permeability. The contribution of each descriptor to MLP-NN model was evaluated. It indicated the importance of the molecular volume and weight. The pattern recognition methods principal component analysis (PCA) and hierarchical clustering analysis (HCA) have been employed in order to investigate the possible qualitative relationships between the molecular descriptors and the corneal permeability. The PCA and HCA results showed that, the data set contains two groups. Then, the same descriptors used in quantitative modeling were considered as inputs of counter propagation neural network (CPNN) to classify the compounds into low permeable (LP) and very low permeable (VLP) categories in supervised manner. The overall classification non error rate was 95.7% and 95.4% for the training and prediction test sets, respectively. The results revealed the ability of CPNN to correctly recognize the compounds belonging to the categories. The proposed models can be successfully used to predict the corneal permeability values and to classify the compounds into LP and VLP ones.
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Prediction of the Corneal Permeability of Drug-Like Compounds. Pharm Res 2010; 27:1398-407. [DOI: 10.1007/s11095-010-0132-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 03/24/2010] [Indexed: 10/19/2022]
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Paolicelli P, de la Fuente M, Sánchez A, Seijo B, Alonso MJ. Chitosan nanoparticles for drug delivery to the eye. Expert Opin Drug Deliv 2009; 6:239-53. [PMID: 19290841 DOI: 10.1517/17425240902762818] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The purpose of this review is to provide the reader with an overview of the advances made in ocular delivery of bioactive molecules by means of chitosan-based nanosystems, and their potential relevance in clinical use. The studies described clearly emphasise that chitosan-based nanostructures are versatile systems that can be tailor-made according to required compositions, surface characteristics and particle size. Such parameters, which are known to influence their in vivo performance, can be modulated by adjusting the formulation conditions of the nanotechnologies responsible for their formation, by incorporating additional materials in the preparation steps, and/or by using synthetically modified chitosan. Moreover, this review illustrates how the advances achieved in the understanding of the interaction of nanosystems with the ocular structures should result in the coming years, logically, into challenging innovations in ocular nanomedicines with significant impact on clinical practice.
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Affiliation(s)
- Patrizia Paolicelli
- University of Santiago de Compostela, Department of Pharmacy and Pharmaceutical Technology, Campus Sur 15782, Santiago de Compostela, Spain
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Quantitative visualization of passive transport across bilayer lipid membranes. Proc Natl Acad Sci U S A 2008; 105:14277-82. [PMID: 18787114 DOI: 10.1073/pnas.0803720105] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The ability to predict and interpret membrane permeation coefficients is of critical importance, particularly because passive transport is crucial for the effective delivery of many pharmaceutical agents to intracellular targets. We present a method for the quantitative measurement of the permeation coefficients of protonophores by using laser confocal scanning microscopy coupled to microelectrochemistry, which is amenable to precise modeling with the finite element method. The technique delivers well defined and high mass transport rates and allows rapid visualization of the entire pH distribution on both the cis and trans side of model bilayer lipid membranes (BLMs). A homologous series of carboxylic acids was investigated as probe molecules for BLMs composed of soybean phosphatidylcholine. Significantly, the permeation coefficient decreased with acyl tail length contrary to previous work and to Overton's rule. The reasons for this difference are considered, and we suggest that the applicability of Overton's rule requires re-evaluation.
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Somasekharan S, Brandt R, Iwamoto T, Tomich JM, Schultz BD. Epithelial barrier modulation by a channel forming peptide. J Membr Biol 2008; 222:17-30. [PMID: 18418541 DOI: 10.1007/s00232-008-9099-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 02/21/2008] [Indexed: 01/07/2023]
Abstract
NC-1059 is a synthetic channel-forming peptide that provides for ion transport across, and transiently reduces the barrier integrity of, cultured epithelial monolayers derived from canine kidney (MDCK cells). Experiments were conducted to determine whether epithelial cells derived from other sources were similarly affected. Epithelial cells derived from human intestine (T-84), airway (Calu-3), porcine intestine (IPEC-J2) and reproductive duct (PVD9902) were grown on permeable supports. Basal short circuit current (Isc) was <3 microA cm(-2) for T-84, IPEC-J2 and PVD9902 cell monolayers and <8 microA cm(-2) for Calu-3 cells. Apical NC-1059 exposure caused, in all cell types, an increase in Isc to >15 microA cm(-2), indicative of net anion secretion or cation absorption, which was followed by an increase in transepithelial conductance (in mS cm(-2): T-84, 1.6 to 62; PVD9902, 0.2 to 51; IPEC-J2, 0.3 to 26; Calu-3, 2.3 to 13). These results are consistent with the peptide affecting transcellular ion movement, with a likely effect also on the paracellular route. NC-1059 exposure increased dextran permeation when compared to basal permeation, which documents an effect on the paracellular pathway. In order to evaluate membrane ion channels, experiments were conducted to study the dose dependence and stability of the NC-1059-induced membrane conductance in Xenopus laevis oocytes. NC-1059 induced a dose-dependent increase in oocyte membrane conductance that remained stable for greater than 2 h. The results demonstrate that NC-1059 increases transcellular conductance and paracellular permeation in a wide range of epithelia. These effects might be exploited to promote drug delivery across barrier epithelia.
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Affiliation(s)
- Suma Somasekharan
- Yale School of Medicine Cellular and Molecular Physiology, New Haven, CT, USA.
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Yasueda SI, Higashiyama M, Yamaguchi M, Isowaki A, Ohtori A. Corneal critical barrier against the penetration of dexamethasone and lomefloxacin hydrochloride: evaluation by the activation energy for drug partition and diffusion in cornea. Drug Dev Ind Pharm 2008; 33:805-11. [PMID: 17729097 DOI: 10.1080/03639040701377995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The cornea is a solid barrier against drug permeation. We searched the critical barrier of corneal drug permeation using a hydrophobic drug, dexamethasone (DM), and a hydrophilic drug, lomefloxacin hydrochloride (LFLX). The activation energies for permeability of DM and LFLX across the intact cornea were 88.0 and 42.1 kJ/mol, respectively. Their activation energies for permeability across the cornea without epithelium decreased to 33.1 and 16.6 kJ/mol, respectively. The results show that epithelium is the critical barrier on the cornea against the permeation of a hydrophobic drug of DM as well as a hydrophilic drug of LFLX. The activation energy of partition for DM (66.8 kJ/mol) was approximately 3-fold larger than that of diffusion (21.2 kJ/mol). The results indicate that the partition for the hydrophobic drug of DM to the corneal epithelium is the primary barrier. Thermodynamic evaluation of activation energy for the drug permeation parameters is a good approach to investigate the mechanism of drug permeability.
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