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Guerra MCA, Neto JT, Gomes MG, Dourado LFN, Oréfice RL, Heneine LGD, Silva-Cunha A, Fialho SL. Nanofiber-coated implants: Development and safety after intravitreal application in rabbits. Int J Pharm 2023; 636:122809. [PMID: 36894043 DOI: 10.1016/j.ijpharm.2023.122809] [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: 10/12/2022] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 03/09/2023]
Abstract
Intravitreal injections are the preferred choice for drug administration to the posterior segment of the eye. However, the required frequent injections may cause complications to the patient and low adherence to the treatment. Intravitreal implants are able to maintain therapeutic levels for a long period. Biodegradable nanofibers can modulate drug release and allow the incorporation of fragile bioactive drugs. Age-related macular degeneration is one of the world major causes of blindness and irreversible vision loss. It involves the interaction between VEGF and inflammatory cells. In this work we developed nanofiber-coated intravitreal implants containing dexamethasone and bevacizumab for simultaneously delivery of these drugs. The implant was successfully prepared and the efficiency of the coating process was confirmed by scanning electron microscopy. Around 68% of dexamethasone was released in 35 days and 88% of bevacizumab in 48hs. The formulation presented activity in the reduction of vessels and was safe to the retina. It was not observed any clinical or histopathological change, neither alteration in retina function or thickness by electroretinogram and optical coherence tomography during 28 days. The nanofiber-coated implants of dexamethasone and bevacizumab may be considered as a new delivery system that can be effective for the treatment of AMD.
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Affiliation(s)
- Maria Carolina Andrade Guerra
- Federal University of Goias, Rua 240 w/n, CEP 74605-220, Goias, Goiania, Brazil; Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro 80, Gameleira, CEP 30510-010, Belo Horizonte, Minas Gerais, Brazil.
| | - Julia Teixeira Neto
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro 80, Gameleira, CEP 30510-010, Belo Horizonte, Minas Gerais, Brazil; Faculty of Pharmacy, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
| | - Michele Gouvea Gomes
- Faculty of Pharmacy, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
| | - Lays Fernanda Nunes Dourado
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro 80, Gameleira, CEP 30510-010, Belo Horizonte, Minas Gerais, Brazil.
| | - Rodrigo Lambert Oréfice
- School of Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
| | - Luiz Guilherme Dias Heneine
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro 80, Gameleira, CEP 30510-010, Belo Horizonte, Minas Gerais, Brazil.
| | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
| | - Silvia Ligorio Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Rua Conde Pereira Carneiro 80, Gameleira, CEP 30510-010, Belo Horizonte, Minas Gerais, Brazil.
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Aggarwal D, Kumar V, Sharma S. Drug-loaded biomaterials for orthopedic applications: A review. J Control Release 2022; 344:113-133. [DOI: 10.1016/j.jconrel.2022.02.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 12/14/2022]
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Castro BFM, Vieira LC, Vasconcelos-Santos DV, Cenachi SPDF, Cotta OAL, Guerra MCA, Paiva MRB, Silva LM, Silva-Cunha A, Fialho SL. Intravitreal thalidomide ameliorates inflammation in a model of experimental uveitis induced by BCG. Int Immunopharmacol 2020; 81:106129. [PMID: 32018067 DOI: 10.1016/j.intimp.2019.106129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/06/2019] [Accepted: 12/16/2019] [Indexed: 02/08/2023]
Abstract
Uveitis encompasses a heterogeneous and complex group of conditions characterized by intraocular inflammation, frequently affecting young individuals and representing an important cause of irreversible blindness worldwide. Animal models have been critical to understand etiology and pathogenesis of uveitis, being also employed to assess new therapeutic strategies, preceding human studies. However, there is still a need of developing and studying different models, due to the difficulties in recapitulating all forms of human uveitis effectively. Although corticosteroids are usually the first-line therapy for non-infectious uveitis, their long-term use is limited by potentially serious side effects in all possible delivery routes. Thus, thalidomide, a drug with anti-inflammatory and antiangiogenic properties, was investigated in a novel experimental model of uveitis, induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG), in rabbits. The experimental protocol consisted of two subcutaneous injections of BCG, followed by two intravitreal injections of the same antigen, inducing panuveitis. Animals were treated with a single intravitreal injection of thalidomide suspension or PBS. Clinical manifestations of uveitis improved after intravitreal thalidomide, involving both anterior and posterior segments. Protein content, N-acetyl-b-glucosaminidase (NAG) and myeloperoxidase (MPO) activities were elevated in ocular tissues after disease induction, further decreasing post-treatment with intravitreal thalidomide. This therapeutic response was also confirmed on ocular electrophysiology, as well as histopathology. This experimental model induced panuveitis in rabbits using a low-cost mycobacterial antigen, with intraocular inflammation subsequently improving after treatment. Intravitreal thalidomide may be a potential alternative to treat intraocular inflammation in corticosteroid-sparing therapies.
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Affiliation(s)
- Brenda Fernanda Moreira Castro
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil, 6627 Presidente Antônio Carlos Avenue, Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Lorena Carla Vieira
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil, 6627 Presidente Antônio Carlos Avenue, Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Daniel Vitor Vasconcelos-Santos
- Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, 190 Professor Alfredo Balena Avenue, Santa Efigênia, Belo Horizonte, Minas Gerais 30130-100, Brazil
| | - Sarah Pereira de Freitas Cenachi
- Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, 190 Professor Alfredo Balena Avenue, Santa Efigênia, Belo Horizonte, Minas Gerais 30130-100, Brazil
| | - Oliver Araújo Lacerda Cotta
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil, 80 Conde Pereira Carneiro Street, Gameleira, Belo Horizonte, Minas Gerais 30510-010, Brazil
| | - Maria Carolina Andrade Guerra
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil, 80 Conde Pereira Carneiro Street, Gameleira, Belo Horizonte, Minas Gerais 30510-010, Brazil.
| | - Mayara Rodrigues Brandão Paiva
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil, 6627 Presidente Antônio Carlos Avenue, Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Luciana Maria Silva
- Cell Biology Laboratory, Ezequiel Dias Foundation, Belo Horizonte, Brazil, 80 Conde Pereira Carneiro Street, Gameleira, Belo Horizonte, Minas Gerais 30510-010, Brazil.
| | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil, 6627 Presidente Antônio Carlos Avenue, Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil.
| | - Sílvia Ligório Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil, 80 Conde Pereira Carneiro Street, Gameleira, Belo Horizonte, Minas Gerais 30510-010, Brazil.
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Toxicity and in vivo release profile of sirolimus from implants into the vitreous of rabbits' eyes. Doc Ophthalmol 2018; 138:3-19. [PMID: 30456454 DOI: 10.1007/s10633-018-9664-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/06/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To assess the in vivo release profile and the retinal toxicity of a poly (lactic-co-glycolic acid) (PLGA) sustained-release sirolimus (SRL) intravitreal implant in normal rabbit eyes. METHODS PLGA intravitreal implants containing or not SRL were prepared, and the viability of ARPE-19 and hES-RPE human retinal cell lines was examined after 24 and 72 h of exposure to implants. New Zealand rabbits were randomly divided into two groups that received intravitreal implants containing or not SRL. At each time point (1-8 weeks), four animals from the SRL group were euthanized, the vitreous was collected, and drug concentration was calculated. Clinical evaluation of the eyes was performed weekly for 8 weeks after administration. Electroretinography (ERG) was recorded in other eight animals, four for each group, at baseline and at 24 h, 1, 4, 6, and 8 weeks after the injection. ERG was carried out using scotopic and photopic protocols. The safety of the implants was assessed using statistical analysis of the ERG parameters (a and b waves, a and b implicit time, B/A ratio, oscillatory potential, and Naka-Rushton analysis) comparing the functional integrity of the retina between the PLGA and SRL-PLGA groups. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology was realized. RESULTS After 24 and 72 h of incubation with PLGA or SRL-PLGA implants, ARPE-19 and hES-RPE cells showed viability over 70%. The maximum concentration of SRL (199.8 ng/mL) released from the device occurred within 4 weeks. No toxic effects of the implants or increase in the intraocular pressure was observed through clinical evaluation of the eye. ERG responses showed no significant difference between the eyes that received PLGA or SRL-PLGA implants at baseline and throughout the 8 weeks of follow-up. No remarkable difference in retinal histopathology was detected in rabbit eyes treated with PLGA or SRL-PLGA implants. CONCLUSIONS Intravitreal PLGA or SRL-PLGA implants caused no significant reduction in cell viability and showed no evident toxic effect on the function or structure of the retina of the animals. SRL was released from PLGA implant after application in the vitreous of rabbits during 8 weeks.
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Cunha RB, Siqueira RC, Messias A, Scott IU, Fialho SL, Cunha-Junior ADS, Jorge R. SAFETY AND FEASIBILITY OF A NOVEL 25-GAUGE BIODEGRADABLE IMPLANT OF DEXAMETHASONE FOR TREATMENT OF MACULAR EDEMA ASSOCIATED WITH RETINAL VEIN OCCLUSION: A PHASE I CLINICAL TRIAL. Retin Cases Brief Rep 2018; 12:50-58. [PMID: 27632583 DOI: 10.1097/icb.0000000000000413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the safety and feasibility of a 25-gauge biodegradable implant containing 350 μg of dexamethasone (DDS-25) for the treatment of decreased vision due to macular edema associated with central or branch retinal vein occlusion. METHODS Prospective, nonrandomized, open-label, Phase I clinical trial, including 10 patients with decreased vision (best-corrected early treatment diabetic retinopathy study visual acuity of 20/40 or worse) due to macular edema associated with central retinal vein occlusion (n = 4) or branch retinal vein occlusion (n = 6) for more than 4 months. Comprehensive ophthalmic evaluation, including best-corrected visual acuity, spectral domain optical coherence tomography (Spectralis Heidelberg Engineering) for determination of central subfield thickness, full-field electroretinography (ISCEV standard ERG), and fluorescein angiography, was performed at baseline, and 1, 4, 12, and 24 weeks after intravitreal DDS-25 insertion. RESULTS Mean best-corrected visual acuity was 0.72 ± 0.1 logMAR (20/100) at baseline and improved by 7 early treatment diabetic retinopathy study letters to 0.58 ± 0.08 logMAR (20/80 + 1) at 24 weeks (P = 0.049), with 3 central retinal vein occlusion and 3 branch retinal vein occlusion patients improving between 1 and 4 early treatment diabetic retinopathy study lines. Significant central subfield thickness reduction was observed at 24 weeks compared with baseline (P = 0.011); mean ± standard error (range) central subfield thickness (μm) was 461.2 ± 41.3 (288-701) at baseline, and 439.6 ± 40.4 (259-631), 442.5 ± 44.6 (255-632), 354.6 ± 31.2 (228-537), and 316.5 ± 26.4 (226-441) at 1, 4, 12, and 24 weeks, respectively. No significant changes in electroretinography responses or area of retinal nonperfusion were observed during 24 weeks of follow-up. There was no significant change in mean intraocular pressure at any of the study visits compared with baseline. One patient had mild anterior chamber inflammation (1-5 cells) at one week after DDS-25 insertion. CONCLUSION In this Phase I study demonstrating the feasibility of intravitreal DDS-25 insertion for the treatment of decreased vision due to macular edema associated with retinal vein occlusion, no safety concerns were observed. A larger prospective randomized study with longer follow-up is warranted to confirm these findings.
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Affiliation(s)
- Renato B Cunha
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto Medical School, University of São Paulo, Brazil
| | - Rubens C Siqueira
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto Medical School, University of São Paulo, Brazil
| | - André Messias
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto Medical School, University of São Paulo, Brazil
| | - Ingrid U Scott
- Departments of Ophthalmology and Public Health Sciences, Penn State College of Medicine, Hershey, Pennsylvania
| | | | | | - Rodrigo Jorge
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto Medical School, University of São Paulo, Brazil
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Chen MY, Tang YJ, Wang YC, Wang CZ, Yuan CS, Chen Y, Tan ZR, Huang WH, Zhou HH. Quantitative determination of betamethasone sodium phosphate and betamethasone dipropionate in human plasma by UPLC-MS/MS and a bioequivalence study. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2016; 8:3550-3563. [PMID: 27695531 PMCID: PMC5042352 DOI: 10.1039/c6ay00202a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The compound medicine of betamethasone sodium phosphate (BSP) and betamethasone dipropionate (BDP) is widely used for diverse glucocorticoid-sensitive acute and chronic diseases such as asthma, rheumatoid arthritis and systemic lupus erythematosus. It will be useful and beneficial to validate sensitive method for the determination of BSP, BDP and their metabolites for their pharmacokinetic study. Hereby, an ultra-high pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been validated for the determination of BSP, BDP and their metabolites betamethasone (BOH), betamethasone 17-monodipropionate (B17P) and betamethasone 21-monodipropionate (B21P) in human plasma. Liquid-liquid extraction with ether and n-hexane (v/v, 4:1) was used for sample preparation of BDP, BOH, B17P and B21P with beclomethasone dipropionate as internal standard (IS), while solid phase extraction was adopted for sample preparation of BSP using prednisolone as IS. The chromatographic separation was performed on a Hypurity C18 column (150 mm×2.1 mm, 5 μm) for BOH, BDP, B21P and B17P, and a Luna C18 (2) column (150 mm×2.0 mm, 5 μm) for BSP. Electrospray ionization interfaced with positive multiple reaction monitoring (MRM) scan mode was used for mass spectrometric detection. The standard calibration curves were linear within the range of 2.525 × 10-9-403.9 × 10-9 mol·dm-3 for BSP, 0.125 × 10-9-55.81 × 10-9 mol·dm-3 for BDP, 0.278 × 10-9-74.95 × 10-9 mol·dm-3 for BOH, 0.098 × 10-9-4.688 × 10-9 mol·dm-3 for B17P and 0.226 × 10-9-5.411 × 10-9 mol·dm-3 for B21P, respectively. The validated method was successfully applied to a bioequivalence study in 23 healthy subjects after they were injected with this compound medicine BSP and BDP.
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Affiliation(s)
- Man-Yun Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
| | - Yong-Jun Tang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
| | - Yi-Cheng Wang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
| | - Chong-Zhi Wang
- Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, University of Chicago; 5841 South Maryland Avenue, MC 4028, Chicago, IL 60637, USA
| | - Chun-Su Yuan
- Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, University of Chicago; 5841 South Maryland Avenue, MC 4028, Chicago, IL 60637, USA
| | - Yao Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
| | - Zhi-Rong Tan
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
| | - Wei-Hua Huang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
- Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, University of Chicago; 5841 South Maryland Avenue, MC 4028, Chicago, IL 60637, USA
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, China
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Perez AC, Cunha Junior ADS, Fialho SL, Silva LM, Dorgam JV, Murashima ADAB, Silva AR, Rossato M, Anselmo-Lima WT. Assessing the maxillary sinus mucosa of rabbits in the presence of biodegradable implants. Braz J Otorhinolaryngol 2013; 78:40-6. [PMID: 23306566 PMCID: PMC9446343 DOI: 10.5935/1808-8694.20120031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 08/23/2012] [Indexed: 11/25/2022] Open
Abstract
In an attempt to improve the quality of life of patients with vitreous humor disease, ophthalmologists began offering steroid-eluting biodegradable implants to their patients. These implants can be used as an alternative treatment for CRS and this is why this experimental study was carried out on rabbit maxillary sinuses. Objective This study aims to assess the histology of the mucosa of the maxillary sinuses of rabbits after the placement of a prednisolone-eluting biodegradable implant. Method Eighteen rabbits were randomly divided into two groups: group 1 - subjects had drug-eluting implants placed on their left maxillary sinuses; group 2 - subjects had non-drug-eluting implants placed on their left maxillary sinuses. The right maxillary sinuses served as the controls. After seven, 14, and 28 days three rabbits in each group were randomly picked to have their tissue inflammatory response assessed. Results Levels of mucosal inflammation were not significantly different between the groups with and without drug-eluting implants and the control group, or when the groups with drug-eluting implants and non-drug-eluting implants were compared. Conclusion Signs of toxicity or mucosal inflammation were not observed in the maxillary sinuses of rabbits given prednisolone-eluting implants or non-drug-eluting implants.
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Affiliation(s)
- André Coura Perez
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes no. 3900, Ribeirão Preto - SP, Brazil.
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Yamazaki Y, Matsunaga T, Syohji K, Arakawa T, Sato T. Effect of anionic/siloxy groups on the release of ofloxacin from soft contact lenses. J Appl Polym Sci 2012. [DOI: 10.1002/app.38114] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Silva GRD, Fialho SL, Siqueira RC, Jorge R, Cunha Júnior ADS. Implants as drug delivery devices for the treatment of eye diseases. BRAZ J PHARM SCI 2010. [DOI: 10.1590/s1984-82502010000300024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The treatment of diseases affecting the posterior segment of the eye is limited by the difficulty in transporting effective doses of drugs to the vitreous, retina, and choroid. Topically applied drugs are poorly absorbed due to the low permeability of the external ocular tissues and tearing. The blood-retina barrier limits drug diffusion from the systemic blood to the posterior segment, thus high doses of drug are needed to maintain therapeutic levels. In addition, systemic side effects are common. Intraocular injections could be an alternative, but the fast flowing blood supply in this region, associated with rapid clearance rates, causes drug concentration to quickly fall below therapeutic levels. To obtain therapeutic levels over longer time periods, polymeric sustained-drug release systems implanted within the vitreous are being studied for the treatment of vitreoretinal disorders. These systems are prepared using different kinds of biodegradable or non-biodegradable polymers. This review aims to demonstrate the main characteristics of these drug delivery implants and their potential for clinical application.
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