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Díaz-Tomé V, García-Otero X, Varela-Fernández R, Martín-Pastor M, Conde-Penedo A, Aguiar P, González-Barcia M, Fernández-Ferreiro A, Otero-Espinar FJ. In situ forming and mucoadhesive ophthalmic voriconazole/HPβCD hydrogels for the treatment of fungal keratitis. Int J Pharm 2021; 597:120318. [PMID: 33540021 DOI: 10.1016/j.ijpharm.2021.120318] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 11/18/2022]
Abstract
Fungal keratitis is a severe infectious corneal disease. At present, no voriconazole ophthalmic formulations are approved by the FDA or EMA. This lack of therapeutic options leads to the reformulation of intravenous voriconazole preparations (VFEND®) by the hospital pharmacy departments to prepare the appropriate ophthalmic formulations (pharmacy compounding). However, the limited residence time of these formulations leads to an intensive treatment posology that may increase the occurrence of side effects. In the present study, two different hydrogels were developed and characterized in order to improve the voriconazole's ophthalmic solubility, permanence, and security. Voriconazole-cyclodextrin (HPβCD or HPɣCD) inclusion complexes in aqueous solutions were characterized by NMR and molecular modeling. Complexes were formed by encapsulation of voriconazole into the cyclodextrin's internal cavity which considerably increases its water solubility. Ocular safety was proven by ocular irritation studies. Permeability studies suggest both hydrogels have good corneal permeability. Furthermore, in vivo ocular permanence study by PET/CT showed a longer permanence time on the ocular surface (t1/2 = 58.91 ± 13.4 min and 96.28 ± 49.11 min for VZHAH and VZISH 0.65 respectively) compared to the voriconazole control formulation (VFEND® t1/2 = 32.27 ± 15.56 min). Results suggest these formulations are a good alternative for the treatment of fungal keratitis.
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Affiliation(s)
- Victoria Díaz-Tomé
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela. Spain; Clinical Pharmacology Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Xurxo García-Otero
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela. Spain; Molecular Imaging Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Rubén Varela-Fernández
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela. Spain; Clinical Neurosciences Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Manuel Martín-Pastor
- Nuclear Magnetic Resonance Unit, Research Infrastructures Area, Universidade de Santiago de Compostela, Campus Vida, Santiago de Compostela, Spain
| | - Andrea Conde-Penedo
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela. Spain
| | - Pablo Aguiar
- Molecular Imaging Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Miguel González-Barcia
- Pharmacy Department. University Clinical Hospital Santiago de Compostela (SERGAS), Santiago de Compostela, Spain; Clinical Pharmacology Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Anxo Fernández-Ferreiro
- Pharmacy Department. University Clinical Hospital Santiago de Compostela (SERGAS), Santiago de Compostela, Spain; Clinical Pharmacology Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), Santiago de Compostela. Spain; Paraquasil Group, University Clinical Hospital, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
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Arumugam SP, Balakrishnan SB, Ganesan V, Munisamy M, Kuppu SV, Narayanan V, Baskaralingam V, Jeyachandran S, Thambusamy S. In-vitro dissolution and microbial inhibition studies on anticancer drug etoposide with β-cyclodextrin. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 102:96-105. [DOI: 10.1016/j.msec.2019.04.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/04/2019] [Accepted: 04/12/2019] [Indexed: 01/28/2023]
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Mohamed-Ahmed AHA, Lockwood A, Li H, Bailly M, Khaw PT, Brocchini S. An Ilomastat-CD Eye Drop Formulation to Treat Ocular Scarring. Invest Ophthalmol Vis Sci 2017; 58:3425-3431. [PMID: 28692737 PMCID: PMC5713897 DOI: 10.1167/iovs.16-21377] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose The purpose of this study was to develop a topical matrix metalloproteinase inhibitor preparation for antiscarring therapy. Methods The broad spectrum matrix metalloproteinase inhibitor ilomastat was formulated using 2-hydroxypropyl-β-cyclodextrin in aqueous solution. In vitro activity of ilomastat-cyclodextrin (ilomastat-CD) was examined using fibroblasts seeded in collagen. Permeation of ilomastat-CD eye drop through pig eye conjunctiva was confirmed using Franz diffusion cells. Ilomastat-CD eye drop was applied to rabbit eyes in vivo, and the distribution of ilomastat in ocular tissues and fluids was determined by liquid chromatography-mass spectroscopy. Results The aqueous solubility of ilomastat-CD was ∼1000 μg/mL in water and 1400 μg/mL in PBS (pH 7.4), which is greater than ilomastat alone (140 and 160 μg/mL in water and PBS, respectively). The in vitro activity of ilomastat-CD to inhibit collagen contraction in the presence of human Tenon fibroblast cells was unchanged compared to uncomplexed ilomastat. Topically administered ilomastat-CD in vivo to rabbit eyes resulted in a therapeutic concentration of ilomastat being present in the sclera and conjunctiva and within the aqueous humor. Conclusions Ilomastat-CD has the potential to be formulated as an eye drop for use as an antifibrotic, which may have implications for the prevention of scarring in many settings, for example glaucoma filtration surgery.
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Affiliation(s)
- Abeer H A Mohamed-Ahmed
- UCL School of Pharmacy, London, United Kingdom 2UCL Institute of Ophthalmology, London, United Kingdom
| | - Alastair Lockwood
- UCL School of Pharmacy, London, United Kingdom 2UCL Institute of Ophthalmology, London, United Kingdom
| | - He Li
- UCL Institute of Ophthalmology, London, United Kingdom
| | - Maryse Bailly
- UCL Institute of Ophthalmology, London, United Kingdom
| | - Peng T Khaw
- UCL Institute of Ophthalmology, London, United Kingdom 3The National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Steve Brocchini
- UCL School of Pharmacy, London, United Kingdom 2UCL Institute of Ophthalmology, London, United Kingdom
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Loftsson T, Stefánsson E. Cyclodextrins and topical drug delivery to the anterior and posterior segments of the eye. Int J Pharm 2017; 531:413-423. [PMID: 28391041 DOI: 10.1016/j.ijpharm.2017.04.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 04/04/2017] [Accepted: 04/05/2017] [Indexed: 12/31/2022]
Abstract
It is generally believed that it is virtually impossible to obtain therapeutic drug concentrations in the posterior segment of the eye after topical application of aqueous, low viscosity eye drops. Thus, intravitreal drug injections and drug implants are currently used to treat diseases in the posterior segment such as macular edema. Here it is described how, through proper analysis of the drug permeation barriers and application of well-known pharmaceutical excipients, aqueous eye drops are designed that can deliver lipophilic drugs to the posterior segment as well as how such eye drops can maintain high drug concentrations in the anterior segment. Through stepwise optimization, eye drops containing solid drug/cyclodextrin complex microparticles with a mean diameter of 2-4μm, dissolved drug/cyclodextrin complex nanoparticles and dissolved drug molecules in an aqueous eye drop media of low viscosity were designed. After administration of the eye drops the microparticles slowly dissolved and maintained close to saturated drug concentrations in the aqueous tear fluid for several hours. Studies in rabbits and clinical evaluations in humans, using dorzolamide and dexamethasone as sample drugs, show that the eye drops deliver significant amounts of drugs to both the posterior segment and anterior segment of the eye. Clinical studies indicate that the eye drops can replace intravitreal injections and implants that are currently used to treat ophthalmic diseases and decrease frequency of drug administration, both of which can improve patient compliance.
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Affiliation(s)
- Thorsteinn Loftsson
- Faculty of Pharmaceutical Sciences, University of Iceland, Hofsvallagata 53, IS-107 Reykjavik, Iceland.
| | - Einar Stefánsson
- Department of Ophthalmology, Faculty of Medicine, National University Hospital, Eiríksgata 37, IS-101 Reykjavík, Iceland
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Barea SA, Mattos CB, Cruz ACC, Chaves VC, Pereira RN, Simões CMO, Kratz JM, Koester LS. Solid dispersions enhance solubility, dissolution, and permeability of thalidomide. Drug Dev Ind Pharm 2016; 43:511-518. [DOI: 10.1080/03639045.2016.1268152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Silvana A. Barea
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cristiane B. Mattos
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ariadne C. C. Cruz
- Programa de Pós-Graduação em Farmácia, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Vitor C. Chaves
- Programa de Pós-Graduação em Farmácia, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Rafael N. Pereira
- Programa de Pós-Graduação em Farmácia, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Claudia M. O. Simões
- Programa de Pós-Graduação em Farmácia, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Jadel M. Kratz
- Programa de Pós-Graduação em Farmácia, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Letícia S. Koester
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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You S, Luo J, Grossniklaus HE, Gou ML, Meng K, Zhang Q. Nanomedicine in the application of uveal melanoma. Int J Ophthalmol 2016; 9:1215-25. [PMID: 27588278 DOI: 10.18240/ijo.2016.08.20] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/16/2016] [Indexed: 12/28/2022] Open
Abstract
Rapid advances in nanomedicine have significantly changed many aspects of nanoparticle application to the eye including areas of diagnosis, imaging and more importantly drug delivery. The nanoparticle-based drug delivery systems has provided a solution to various drug solubility-related problems in ophthalmology treatment. Nanostructured compounds could be used to achieve local ocular delivery with minimal unwanted systematic side effects produced by taking advantage of the phagocyte system. In addition, the in vivo control release by nanomaterials encapsulated drugs provides prolong exposure of the compound in the body. Furthermore, certain nanoparticles can overcome important body barriers including the blood-retinal barrier as well as the corneal-retinal barrier of the eye for effective delivery of the drug. In summary, the nanotechnology based drug delivery system may serve as an important tool for uveal melanoma treatment.
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Affiliation(s)
- Shuo You
- Department of Endocrinology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China; Winship Cancer Institute, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
| | - Jing Luo
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
| | - Hans E Grossniklaus
- Winship Cancer Institute, School of Medicine, Emory University, Atlanta, Georgia 30322, USA; Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia 30322, USA; Department of Pathology, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
| | - Ma-Ling Gou
- State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ke Meng
- State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Qing Zhang
- Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China; Department of Ophthalmology, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
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Adelli GR, Balguri SP, Majumdar S. Effect of Cyclodextrins on Morphology and Barrier Characteristics of Isolated Rabbit Corneas. AAPS PharmSciTech 2015; 16:1220-6. [PMID: 25771740 DOI: 10.1208/s12249-015-0315-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 02/28/2015] [Indexed: 11/30/2022] Open
Abstract
The objective of the present study is to investigate the confounding effects, if any, of beta-cyclodextrins (βCDs) on corneal permeability coefficients obtained from in vitro transmembrane diffusion studies. Transcorneal permeability studies were carried out with 2-hydroxypropyl-beta-cyclodextrin (HPβCD) and randomly methylated-beta-cyclodextrin (RMβCD) at 5 and 2.5%w/v in isotonic phosphate-buffered solution (IPBS) (pH 7.4). Rabbit corneas received from Pel-Freez Biologicals® were used for these studies. Propranolol hydrochloride (PHCl) (1 mg/mL) was used as the paracellular permeability marker. A series of permeation studies were carried out with IPBS as the control, with CDs on the donor side only, CDs on the receiver side only, and CDs on both the donor and receiver sides. At the end of 1 or 3 h, corneas were collected and fixed using a solution containing 2%v/v glutaraldehyde + 2%w/v paraformaldehyde + IPBS and histological examinations were performed (Excalibur Pathology, Inc). The order of transcorneal permeability of PHCl was found to be CDs on the receiver side > control (no CDs) ≈ CDs on both the receiver and donor sides > CDs on the donor side. Histology studies revealed that the corneal epithelial and endothelial layers remained intact in the control sets. Damage to the cornea was observed in the order of CDs on the receiver side > CDs on the donor side > CDs on both sides > control. The use of CDs in solutions for in vitro permeation experiments with rabbit corneas needs to be carefully considered to avoid confounding effects in the data obtained.
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Gonzalez L, Loza RJ, Han KY, Sunoqrot S, Cunningham C, Purta P, Drake J, Jain S, Hong S, Chang JH. Nanotechnology in corneal neovascularization therapy--a review. J Ocul Pharmacol Ther 2013; 29:124-34. [PMID: 23425431 DOI: 10.1089/jop.2012.0158] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nanotechnology is an up-and-coming branch of science that studies and designs materials with at least one dimension sized from 1-100 nm. These nanomaterials have unique functions at the cellular, atomic, and molecular levels. The term "nanotechnology" was first coined in 1974. Since then, it has evolved dramatically and now consists of distinct and independent scientific fields. Nanotechnology is a highly studied topic of interest, as nanoparticles can be applied to various fields ranging from medicine and pharmacology, to chemistry and agriculture, to environmental science and consumer goods. The rapidly evolving field of nanomedicine incorporates nanotechnology with medical applications, seeking to give rise to new diagnostic means, treatments, and tools. Over the past two decades, numerous studies that underscore the successful fusion of nanotechnology with novel medical applications have emerged. This has given rise to promising new therapies for a variety of diseases, especially cancer. It is becoming abundantly clear that nanotechnology has found a place in the medical field by providing new and more efficient ways to deliver treatment. Ophthalmology can also stand to benefit significantly from the advances in nanotechnology research. As it relates to the eye, research in the nanomedicine field has been particularly focused on developing various treatments to prevent and/or reduce corneal neovascularization among other ophthalmologic disorders. This review article aims to provide an overview of corneal neovascularization, currently available treatments, and where nanotechnology comes into play.
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Affiliation(s)
- Lilian Gonzalez
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL 60612, USA
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Kratz JM, Teixeira MR, Ferronato K, Teixeira HF, Koester LS, Simões CMO. Preparation, characterization, and in vitro intestinal permeability evaluation of thalidomide-hydroxypropyl-β-cyclodextrin complexes. AAPS PharmSciTech 2012; 13:118-24. [PMID: 22160886 DOI: 10.1208/s12249-011-9739-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 11/29/2011] [Indexed: 01/15/2023] Open
Abstract
Thalidomide is emerging as a therapeutic agent with renewed clinical importance, presenting anti-inflammatory, immunomodulatory, and antineoplasic properties. In this work, we studied the complexation of thalidomide with cyclodextrins as a strategy to circumvent the poor aqueous solubility of the drug. Thalidomide-hydroxypropyl-β-cyclodextrin complexes were obtained by kneading method and were characterized by differential scanning calorimetry, powder X-ray diffractometry, and scanning electronic microscopy. The aqueous solubility and in vitro dissolution of thalidomide were significantly improved through the complexation. Physicochemical analysis of the complexes in solid state revealed a decreased crystallinity of the complexed drug in comparison with free thalidomide. Thalidomide was able to dissociate from the complexes and permeates across intestinal epithelial Caco-2 cells with a favorable high permeability profile equivalent to that of the free drug. In summary, the present results suggest that thalidomide-hydroxypropyl-β-cyclodextrin complexes could be regarded as a promising strategy for improving the gastrointestinal absorption of thalidomide.
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Bucolo C, Melilli B, Piazza C, Zurria M, Drago F. Ocular Pharmacokinetics Profile of Different Indomethacin Topical Formulations. J Ocul Pharmacol Ther 2011; 27:571-6. [DOI: 10.1089/jop.2011.0120] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Claudio Bucolo
- Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, Catania, Italy
| | | | | | - Monia Zurria
- Research and Development, AlfaIntes, Casoria, Italy
| | - Filippo Drago
- Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, Catania, Italy
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Loftsson T, Brewster ME. Pharmaceutical applications of cyclodextrins: effects on drug permeation through biological membranes. J Pharm Pharmacol 2011; 63:1119-35. [DOI: 10.1111/j.2042-7158.2011.01279.x] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Abstract
Objectives
Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories.
Key findings
Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are most useful when they interact with lipophiles in systems where such an UWL is present and contributes significantly to the barrier properties of the membrane. Furthermore, these principles are used to direct the optimal formulation of drugs in cyclodextrins. A second related critical success factor in the formulation of cyclodextrin-based drug product is an understanding of the kinetics and thermodynamics of complexation and the need to optimize the cyclodextrin amount and drug-to-cyclodextrin ratios. Drug formulations, especially those targeting compartments associated with limited dissolution (i.e. the eye, subcutaneous space, etc.), should be carefully designed such that the thermodynamic activity of the drug in the formulation is optimal meaning that there is sufficient cyclodextrin to solubilize the drug but not more than that. Increasing the cyclodextrin concentration decreases the formulation ‘push’ and may reduce the bioavailability of the system.
Conclusions
A mechanism-based understanding of cyclodextrin complexation is essential for the appropriate formulation of contemporary drug candidates.
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Affiliation(s)
- Thorsteinn Loftsson
- Faculty of Pharmaceutical Sciences, University of Iceland, Hofsvallagata, Reykjavik, Iceland
| | - Marcus E Brewster
- Pharmaceutical Development and Manufacturing Sciences, Janssen Research and Development, Johnson & Johnson, Scheperstraat, Beerse, Belgium
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Zhang L, Zhang J, Wang L, Xia H. Ocular pharmacokinetics and availability of topically applied baicalein in rabbits. Curr Eye Res 2009; 34:257-63. [PMID: 19373573 DOI: 10.1080/02713680902725962] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To evaluate the ocular pharmacokinetics and availability of baicalein following topical application. METHODS Hydroxypropyl beta-cyclodextrin (HP-beta -CD) was used to formulate an aqueous eye drop to improve aqueous solubility of baicalein. A single dose of either baicalein suspension (1%) (Bai-SP) or baicalein (1%)/HP-beta-CD (10%) solution (Bai-CD) was topically applied to rabbits. Aqueous humor and cornea were collected after 5, 10, 20, 30, 45, 60, 90, and 120 min. Baicalein concentrations were determined by high-performance liquid chromatography (HPLC) after extraction. RESULTS After topically applying Bai-CD, the baicalein concentrations in aqueous humor were significantly increased at 20-120 min except at 90 min compared with those of Bai-SP (p < 0.05). The highest levels of baicalein in aqueous humor (Cmax, 4.11 +/- 0.75 microg/ml) were obtained after 30 min application of Bai-CD, 3.6 times greater than that corresponding to the Bai-SP at 20 min. The Bai-CD produced an over 2.1-fold bioavailability (AUC(0-120), area under the concentration time curve between 0 and 120 min) increase in aqueous humor compared to the Bai-SP. Peak baicalein concentration in cornea (56.53 +/- 17.02 microg/g) was achieved within 5 min after topical application of Bai-CD and 4.5 times higher than that of Bai-SP at the same timepoint. The baicalein levels in corneas obtained after application of Bai-CD were all much higher than those obtained by Bai-SP (p < 0.01), whereas the drug levels became undetectable 30 min after topical application of Bai-SP. CONCLUSION Bai-CD formulation is superior to Bai-SP for increasing ocular bioavailability.
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Affiliation(s)
- Li Zhang
- Henan Eye Institute, No. 7 Weiwu Road, Zhengzhou, Henan Province 450003, China.
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Zhang J, Wang L, Gao C, Zhang L, Xia H. Ocular Pharmacokinetics of Topically-Applied Ketoconazole Solution Containing Hydroxypropyl Beta-Cyclodextrin to Rabbits. J Ocul Pharmacol Ther 2008; 24:501-6. [DOI: 10.1089/jop.2008.0015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Junjie Zhang
- Pharmaceutic and Pharmacology Department, Henan Eye Institute, Henan Key Laboratory of Keratopathy, Zhengzhou, China
| | - Liya Wang
- Pharmaceutic and Pharmacology Department, Henan Eye Institute, Henan Key Laboratory of Keratopathy, Zhengzhou, China
| | - Changfeng Gao
- Pharmaceutic and Pharmacology Department, Henan Eye Institute, Henan Key Laboratory of Keratopathy, Zhengzhou, China
| | - Li Zhang
- Pharmaceutic and Pharmacology Department, Henan Eye Institute, Henan Key Laboratory of Keratopathy, Zhengzhou, China
| | - Huiyun Xia
- Pharmaceutic and Pharmacology Department, Henan Eye Institute, Henan Key Laboratory of Keratopathy, Zhengzhou, China
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Rodrigues GB, Passos GF, Di Giunta G, Figueiredo CP, Rodrigues EB, Grumman A, Medeiros R, Calixto JB. Preventive and therapeutic anti-inflammatory effects of systemic and topical thalidomide on endotoxin-induced uveitis in rats. Exp Eye Res 2007; 84:553-60. [PMID: 17223105 DOI: 10.1016/j.exer.2006.11.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 11/03/2006] [Accepted: 11/14/2006] [Indexed: 10/23/2022]
Abstract
The present study examined the outcomes of systemic or topical treatment with thalidomide, a compound that possesses anti-inflammatory, immunomodulatory and anti-angiogenic properties, in rats subjected to endotoxin-induced uveitis (EIU). The effects of thalidomide were evaluated on endotoxin-induced leucocyte and protein infiltration and also on the production of interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha in rat aqueous humour (AqH). Moreover, the actions of thalidomide were assessed on the cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein expression in retinal tissue. EIU was produced by a hindpaw injection of lipopolysaccharide (LPS), in male Wistar rats. Thalidomide (5, 25 and 50 mg/kg) was administered orally 1 h before LPS injection. In another set of experiments, to evaluate the therapeutic efficacy, 5% thalidomide was applied topically to both eyes at 6, 12 and 18 h after LPS administration. The oral pre-treatment with thalidomide decreased, in a dose-dependent manner, the number of inflammatory cells, the protein concentration, and the levels of IL-1beta and TNF-alpha in the AqH. Similar results were found in the AqH of rats that received a topical application of thalidomide. Furthermore, oral (50 mg/kg) and local (5%) thalidomide treatment also reduced expression of the pro-inflammatory proteins COX-2 and iNOS in the posterior segment of the eye. Thalidomide exhibited marked preventive and curative ocular effects in EIU in rats, a property that might be associated with its ability to inhibit the production of inflammatory cytokines and the expression of COX-2 and iNOS. This assembly of data provides additional molecular and functional insights into beneficial effects of thalidomide as an agent for the management of ocular inflammation.
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Affiliation(s)
- Gustavo Büchele Rodrigues
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP 88049-900, Florianópolis, SC, Brazil
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Loftsson T, Stefánsson E. Cyclodextrins in ocular drug delivery: theoretical basis with dexamethasone as a sample drug. J Drug Deliv Sci Technol 2007. [DOI: 10.1016/s1773-2247(07)50001-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bertelmann E, Pleyer U. Immunomodulatory Therapy in Ophthalmology – Is There a Place for Topical Application? Ophthalmologica 2004; 218:359-67. [PMID: 15564752 DOI: 10.1159/000080937] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Accepted: 01/23/2004] [Indexed: 11/19/2022]
Abstract
Topical corticosteroids, although effective in the treatment of ocular immune-mediated diseases, are well known for their ocular side-effects. Not surprisingly, a variety of alternative immunomodulatory agents have been tested for topical use including cyclosporin A (CsA), mycophenolate mofetil (MMF), tacrolimus (FK506), rapamycin (sirolimus) and leflunomide. Local application bears the possibility to avoid the severe side-effects of systemic therapy. The effect of topical therapy is naturally restricted to local immune response mechanisms, such as antigen presentation by Langerhans and dendritic cells. Moreover, many immunomodulatory agents (e.g. CsA) are lipophilic and thus have low water solubility and penetrate insufficiently intra-ocularly, often being stored in the lipophilic corneal epithelial barrier. Therefore, the therapeutical success is limited for intra-ocular immune-mediated diseases like anterior uveitis. However, a multitude of strategies have been introduced to circumvent these problems including complexing substances such as cyclodextrins (CDs) and liposomes. In the prevention and treatment of transplant rejection after keratoplasty, many attempts to introduce topical immunomodulatory therapy have failed; on the other hand, further therapeutic options not primarily expected are being evaluated today such as treatment of severe keratoconjunctivitis sicca. In our own studies, we investigated the pharmacokinetics of topical treatment with different agents including MMF and evaluated the efficacy of topical treatment in animal models for uveitis and keratoplasty. Taken together, topical immunomodulatory therapy will not replace systemic therapy but further treatment options can be expected.
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Affiliation(s)
- Eckart Bertelmann
- Augenklinik Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Deutschland.
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Knapp S, Bertelmann E, Hartmann C, Keipert S, Pleyer U. Intraocular availability of topically applied mycophenolate mofetil in rabbits. J Ocul Pharmacol Ther 2003; 19:181-92. [PMID: 12804063 DOI: 10.1089/108076803321637717] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The efficacy of mycophenolate mofetil (MMF), a prodrug of mycophenolic acid (MPA), in high risk keratoplasties and ocular immune-mediated diseases has been shown in recent years. As peroral administration of MMF can cause various side effects, topical application should be considered. This study investigates the intraocular availability of MMF and MPA in the rabbit eye. An eye drop solution (MMF-CD; 1% MMF/10% hydroxypropyl-beta-cyclodextrin (HP-beta-CD)) or a 1% aqueous suspension (MMF-SP) was instilled into the lower cul-de-sac of the right eye of each rabbit. Rabbits (each group: n = 4) were put down after 30, 60 and 240 min. Aqueous humor, vitreous, cornea, sclera, conjunctiva, iris-ciliary-body, and plasma were isolated. Several extraction procedures were performed in order to quantify the drug by HPLC. The aqueous humor concentration of the active metabolite MPA was 24 microg/mL after 30 min for both preparations. The ratio of the MPA concentrations after 30, 60, and 240 min was 1 : 2 : 0.07 for MMF-CD and 1 : 0.6 : 0.04 for MMF-SP, respectively. MPA levels in the cornea were 90.78 / 56.90 / 4.08 x 10(-6) microg/microg for MMF-CD, whereas MMF-SP resulted in MPA levels of 102.65 / 31.18 / 2.59 x 10(-6) microg/microg at the three time points. As a high concentration of the active drug MPA in cornea and aqueous humor is desired, e.g. following corneal transplantation, the MMF/HP-beta-CD formulation could be an useful topical treatment. Furthermore, the present study shows that MMF-CD is superior to MMF-SP by increasing intraocular availability.
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Affiliation(s)
- Sigrid Knapp
- Institut für Pharmazie, Humboldt Universität zu Berlin, Goethestr. 54, 13086 Berlin, Germany.
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Abstract
The leading cause of irreversible blindness is glaucoma, a disease normally characterized by the development of ocular hypertension and consequent damage to the optic nerve at its point of retinal attachment. This results in a narrowing of the visual field, and eventually results in blindness. A number of drugs are available to lower intraocular pressure (IOP), but, occasionally, they are ineffective or have intolerable side-effects for some patients and can lose efficacy with chronic administration. The smoking of marijuana has decreased IOP in glaucoma patients. Cannabinoid drugs, therefore, are thought to have significant potential for pharmaceutical development. However, as the mechanism surrounding their effect on IOP initially was thought to involve the CNS, issues of psychoactivity hindered progress. The discovery of ocular cannabinoid receptors implied an explanation for the induction of hypotension by topical cannabinoid applications, and has stimulated a new phase of ophthalmic cannabinoid research. Featured within these investigations is the possibility that at least some cannabinoids may ameliorate optic neuronal damage through suppression of N-methyl-D-aspartate receptor hyperexcitability, stimulation of neural microcirculation, and the suppression of both apoptosis and damaging free radical reactions, among other mechanisms. Separation of therapeutic actions from side-effects now seems possible through a diverse array of novel chemical, pharmacological, and formulation strategies.
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Affiliation(s)
- Tomi Järvinen
- Department of Pharmaceutical Chemistry, University of Kuopio, Finland.
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Loftsson T, Stefánsson E. Cyclodextrins in eye drop formulations: enhanced topical delivery of corticosteroids to the eye. ACTA OPHTHALMOLOGICA SCANDINAVICA 2002; 80:144-50. [PMID: 11952479 DOI: 10.1034/j.1600-0420.2002.800205.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cyclodextrins are cylindrical oligosaccharides with a lipophilic central cavity and hydrophilic outer surface. They can form water-soluble complexes with lipophilic drugs, which 'hide' in the cavity. Cyclodextrins can be used to form aqueous eye drop solutions with lipophilic drugs, such as steroids and some carbonic anhydrase inhibitors. The cyclodextrins increase the water solubility of the drug, enhance drug absorption into the eye, improve aqueous stability and reduce local irritation. Cyclodextrins are useful excipients in eye drop formulations of various drugs, including steroids of any kind, carbonic anhydrase inhibitors, pilocarpine, cyclosporins, etc. Their use in ophthalmology has already begun and is likely to expand the selection of drugs available as eye drops. In this paper we review the properties of cyclodextrins and their application in eye drop formulations, of which their use in the formulation of dexamethasone eye drops is an example. Cyclodextrins have been used to formulate eye drops containing corticosteroids, such as dexamethasone, with levels of concentration and ocular absorption which, according to human and animal studies, are many times those seen with presently available formulations. Cyclodextrin-based dexamethasone eye drops are well tolerated in the eye and seem to provide a higher degree of bioavailability and clinical efficiency than the steroid eye drop formulations presently available. Such formulations offer the possibility of once per day application of corticosteroid eye drops after eye surgery, and more intensive topical steroid treatment in severe inflammation. While cyclodextrins have been known for more than a century, their use in ophthalmology is just starting. Cyclodextrins are useful excipients in eye drop formulations for a variety of lipophilic drugs. They will facilitate eye drop formulations for drugs that otherwise might not be available for topical use, while improving absorption and stability and decreasing local irritation.
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Affiliation(s)
- Thorsteinn Loftsson
- Faculties of Pharmacy and Medicine, University of Iceland, Reykjavik, Iceland
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Abstract
Cyclodextrins are cyclic oligosaccharides with a hydrophilic outer surface and a somewhat lipophilic central cavity. Cyclodextrins are able to form water-soluble inclusion complexes with many lipophilic water-insoluble drugs. In aqueous solutions drug molecules located in the central cavity are in a dynamic equilibrium with free drug molecules. Furthermore, lipophilic molecules in the aqueous complexation media will compete with each other for a space in the cavity. Due to their size and hydrophilicity only insignificant amounts of cyclodextrins and drug/cyclodextrin complexes are able to penetrate into lipophilic biological barriers, such as intact skin. In general, cyclodextrins enhance topical drug delivery by increasing the drug availability at the barrier surface. At the surface the drug molecules partition from the cyclodextrin cavity into the lipophilic barrier. Thus, drug delivery from aqueous cyclodextrin solutions is both diffusion controlled and membrane controlled. It appears that cyclodextrins can only enhance topical drug delivery in the presence of water.
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Affiliation(s)
- T Loftsson
- Faculty of Pharmacy, University of Iceland, Hofsvallagata 53, PO Box 7210, IS-107, Reykjavik, Iceland.
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Pose-Vilarnovo B, Perdomo-López I, Echezarreta-López M, Schroth-Pardo P, Estrada E, Torres-Labandeira JJ. Improvement of water solubility of sulfamethizole through its complexation with beta- and hydroxypropyl-beta-cyclodextrin. Characterization of the interaction in solution and in solid state. Eur J Pharm Sci 2001; 13:325-31. [PMID: 11384856 DOI: 10.1016/s0928-0987(01)00131-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of this study was to increase the solubility of sulfamethizole in water by complexing it with beta-cyclodextrin (BCD) and hydroxypropyl-beta-cyclodextrin (HPBCD). The interaction of sulfamethizole with the cyclodextrins was evaluated by the solubility, 1H NMR spectrometry and molecular modelling. The stability constants calculated from the phase solubility method increase in order HPBCD<BCD. From the NMR studies could be concluded that the sulfamethizole:cyclodextrin mole ratio was 1:1 (mol/mol) in the BCD complex and 2:3 (mol/mol) in the HPBCD complex. In both cases the sulfamethizole moiety included in the cyclodextrin was the thiadiazole group. MM2 calculations, either in vacuum or in the presence of a solvent, support this structure. Solid inclusion complexes of sulfamethizole with BCD and HPBCD were obtained by freeze drying 1:1 (mol/mol) solutions in aqueous ammonium hydroxide. Host-guest interactions were studied in the solid state by powder X-ray diffractometry and differential scanning calorimetry. The dissolution rates of sulfamethizole increased by the complexation with BCD or HPBCD.
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Affiliation(s)
- B Pose-Vilarnovo
- Departamento de Farmacia e Tecnoloxía Farmacéutica, Fac. de Farmacia, Univ. de Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela, Spain
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