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Sadeghi A, Ruponen M, Puranen J, Cao S, Ridolfo R, Tavakoli S, Toropainen E, Lajunen T, Ranta VP, van Hest J, Urtti A. Imaging, quantitation and kinetic modelling of intravitreal nanomaterials. Int J Pharm 2022; 621:121800. [DOI: 10.1016/j.ijpharm.2022.121800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/15/2022] [Accepted: 04/30/2022] [Indexed: 12/01/2022]
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2
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Rotov AY, Romanov IS, Tarakanchikova YV, Astakhova LA. Application Prospects for Synthetic Nanoparticles in Optogenetic Retinal Prosthetics. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021060132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Retinal and Corneal Toxicity and Pharmacokinetic Analysis of Intraocular Injection of Ganciclovir in Rabbit Eyes. J Ophthalmol 2019; 2019:3054758. [PMID: 31205782 PMCID: PMC6530113 DOI: 10.1155/2019/3054758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/28/2019] [Accepted: 04/21/2019] [Indexed: 01/25/2023] Open
Abstract
Purpose To evaluate the safety and pharmacokinetic changes of ganciclovir (GCV) intraocular injection. Methods GCV (2 mg/0.1 mL) was injected into rabbit eyes. Aqueous GCV concentration was detected by high-performance liquid chromatography. Potential toxicity was assessed by slit-lamp examination, optical coherence tomography, fundus examination, confocal microscopy, and histology. Results Aqueous GCV concentrations were 24.83 ± 6.41 μg/mL, 0.65 ± 0.52 μg/mL, and undetected on the 1st, 3rd, and 7th day after intravitreal injection. GCV could not be detected on the first day after intracameral injection. No corneal abnormality was found after intravitreal injection, but retinal edema was observed on the first day which receded later. Corneal edema was obvious with endothelial cytoarchitecture damaged after intracameral injection; fluid retention also existed in retina. Conclusions GCV intravitreal injection offers effective, sustained drug concentration in the anterior chamber, and its damage to retina receded over time. Intracameral injection results in rapid drug elimination and severe damage to endothelium and thus is not recommended.
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Yang C, Gao L, Liu X, Yang T, Yin G, Chen J, Guo H, Yu B, Cong H. Injectable Schiff base polysaccharide hydrogels for intraocular drug loading and release. J Biomed Mater Res A 2019; 107:1909-1916. [DOI: 10.1002/jbm.a.36677] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/10/2019] [Accepted: 03/15/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Chao Yang
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
- Institute of Complexity Science, Automation CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Lilong Gao
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Xiyan Liu
- Marine Chemical Research Institute Qingdao Shandong, 266071 People's Republic of China
| | - Ting Yang
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Guangming Yin
- Material Science and Engineering CollegeBeijing University of Chemical Technology Beijing, 100029 People's Republic of China
| | - Jianyu Chen
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Haiyong Guo
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Bing Yu
- Chemistry and Chemical Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
| | - Hailin Cong
- Material Science and Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
- Chemistry and Chemical Engineering CollegeQingdao University Qingdao Shandong, 266071 People's Republic of China
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Joseph RR, Venkatraman SS. Drug delivery to the eye: what benefits do nanocarriers offer? Nanomedicine (Lond) 2017; 12:683-702. [PMID: 28186436 DOI: 10.2217/nnm-2016-0379] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ocular drug delivery has seen several advances in the past few decades, with respect to new drugs, improved formulations, targeted delivery, as well as exploration of new routes of drug administration. New materials have been explored for encasing existing drugs, which can enhance treatment by increasing bioavailability, decreasing toxicity, providing better tissue adherence, targeted delivery as well as increased duration of action. The challenges and requirements are different for the anterior and posterior ocular segments. This review summarizes the recent advances in sustained ocular therapy, both to the anterior and posterior segments, which have been made possible, thanks to nanotechnology. We also discuss the distribution and fate of these nanocarriers themselves, postadministration, as well as clearance from ocular tissues.
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Affiliation(s)
- Rini Rachel Joseph
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Subbu S Venkatraman
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore.,NTU-Northwestern Institute for Nanomedicine, School of Materials Science & Engineering (MSE), Nanyang Technological University, Singapore 639798, Singapore
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Käsdorf BT, Arends F, Lieleg O. Diffusion Regulation in the Vitreous Humor. Biophys J 2016; 109:2171-81. [PMID: 26588575 DOI: 10.1016/j.bpj.2015.10.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/28/2015] [Accepted: 10/01/2015] [Indexed: 02/02/2023] Open
Abstract
The efficient treatment of many ocular diseases depends on the rapid diffusive distribution of solutes such as drugs or drug delivery vehicles through the vitreous humor. However, this multicomponent hydrogel possesses selective permeability properties, which allow for the diffusion of certain molecules and particles, whereas others are immobilized. In this study, we perform an interspecies comparison showing that the selective permeability properties of the vitreous are conserved across several mammalian species. We identify the polyanionic glycosaminoglycans hyaluronic acid and heparan sulfate as two key macromolecules that establish this selective permeability. We show that electrostatic interactions between the polyanionic macromolecules and diffusing solutes can be weakened by charge screening or enzymatic glycosaminoglycan digestion. Furthermore, molecule penetration into the vitreous is also charge-dependent and only efficient as long as the net charge of the molecule does not exceed a certain threshold.
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Affiliation(s)
- Benjamin Tillmann Käsdorf
- Institute of Medical Engineering (IMETUM), Technische Universität München, Garching, Germany; Department of Mechanical Engineering, Technische Universität München, Garching, Germany
| | - Fabienna Arends
- Institute of Medical Engineering (IMETUM), Technische Universität München, Garching, Germany; Department of Mechanical Engineering, Technische Universität München, Garching, Germany
| | - Oliver Lieleg
- Institute of Medical Engineering (IMETUM), Technische Universität München, Garching, Germany; Department of Mechanical Engineering, Technische Universität München, Garching, Germany.
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Preparation and in vivo evaluation of nanoliposomes containing melphalan after intravitreal injection in albino rabbits. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2016. [DOI: 10.1007/s40005-016-0271-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Nanotherapy for posterior eye diseases. J Control Release 2014; 193:100-12. [PMID: 24862316 DOI: 10.1016/j.jconrel.2014.05.031] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/12/2014] [Accepted: 05/17/2014] [Indexed: 12/11/2022]
Abstract
It is assumed that more than 50% of the most enfeebling ocular diseases have their origin in the posterior segment. Furthermore, most of these diseases lead to partial or complete blindness, if left untreated. After cancer, blindness is the second most dreaded disease world over. However, treatment of posterior eye diseases is more challenging than the anterior segment ailments due to a series of anatomical barriers and physiological constraints confronted for delivery to this segment. In this regard, nanostructured drug delivery systems are proposed to defy ocular barriers, target retina, and act as permeation enhancers in addition to providing a controlled release. Since an important step towards developing effective treatment strategies is to understand the course or a route a drug molecule needs to follow to reach the target site, the first part of the present review discusses various pathways available for effective delivery to and clearance from the posterior eye. Promise held by nanocarrier systems, viz. liposomes, nanoparticles, and nanoemulsion, for effective delivery and selective targeting is also discussed with illustrative examples, tables, and flowcharts. However, the applicability of these nanocarrier systems as self-administration ocular drops is still an unrealized dream which is in itself a huge technological challenge.
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Honda M, Asai T, Oku N, Araki Y, Tanaka M, Ebihara N. Liposomes and nanotechnology in drug development: focus on ocular targets. Int J Nanomedicine 2013; 8:495-503. [PMID: 23439842 PMCID: PMC3576887 DOI: 10.2147/ijn.s30725] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Poor drug delivery to lesions in patients’ eyes is a major obstacle to the treatment of ocular diseases. The accessibility of these areas to drugs is highly restricted by the presence of barriers, including the corneal barrier, aqueous barrier, and the inner and outer blood–retinal barriers. In particular, the posterior segment is difficult to reach for drugs because of its structural peculiarities. This review discusses various barriers to drug delivery and provides comprehensive information for designing nanoparticle-mediated drug delivery systems for the treatment of ocular diseases. Nanoparticles can be designed to improve penetration, controlled release, and drug targeting. As highlighted in this review, the therapeutic efficacy of drugs in ocular diseases has been reported to be enhanced by the use of nanoparticles such as liposomes, micro/nanospheres, microemulsions, and dendrimers. Our recent data show that intravitreal injection of targeted liposomes encapsulating an angiogenesis inhibitor caused significantly greater suppression of choroidal neovascularization than did the injection of free drug. Recent progress in ocular drug delivery systems research has provided new insights into drug development, and the use of nanoparticles for drug delivery is thus a promising approach for advanced therapy of ocular diseases.
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Affiliation(s)
- Miki Honda
- Department of Ophthalmology, Juntendo University Urayasu Hospital, Chiba, Japan.
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Lim SB, Banerjee A, Önyüksel H. Improvement of drug safety by the use of lipid-based nanocarriers. J Control Release 2012; 163:34-45. [PMID: 22698939 DOI: 10.1016/j.jconrel.2012.06.002] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/21/2012] [Accepted: 06/01/2012] [Indexed: 01/01/2023]
Abstract
Drug toxicity is an important factor that contributes significantly to adverse drug events in current healthcare practice. Application of lipid-based nanocarriers in drug formulation is one approach to improve drug safety. Lipid-based delivery systems include micelles, liposomes, solid lipid nanoparticles, nanoemulsions and nanosuspensions. These carriers are generally composed of physiological lipids well tolerated by human body. Delivery of water-insoluble drugs in these formulations increases their solubility and stability in aqueous media and eliminates the need for toxic co-solvents or pH adjustment to solubilize hydrophobic drugs. Association or encapsulation of peptides/proteins within lipid-based carriers protects the labile biologics against enzymatic degradation, hence reducing the therapeutic dose required and risk of dose-dependent toxicity. Most importantly, lipid-based nanocarriers alter the pharmacokinetics and biodistribution of drugs through passive and active targeting, leading to increased drug accumulation at target sites while significantly decreasing non-specific distribution to other tissues. Furthermore, surface modification of these nanocarriers reduces immunogenicity of drug-carrier complexes, imparts stealth by preventing opsonization and removal by phagocytes and minimizes interaction with circulating blood components. In view of heightening attention on drug safety in patient treatment, lipid-based nanocarrier is therefore an important and promising option for formulation of pharmaceutical products to improve treatment safety and efficacy.
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Affiliation(s)
- Sok Bee Lim
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60612-7231, USA
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Liposomes for intravitreal drug delivery: a state of the art. J Control Release 2012; 161:628-34. [PMID: 22289436 DOI: 10.1016/j.jconrel.2012.01.019] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/14/2012] [Accepted: 01/16/2012] [Indexed: 12/16/2022]
Abstract
Intravitreal administration of drugs has raised a large interest during the last two decades improving the treatment of infectious diseases of the posterior segment of the eye or edematous maculopathies. This route of administration allows achieving high drug concentrations in the vitreous and avoiding adverse effects resulting from systemic administration. However, many drugs are rapidly cleared from the vitreous humor; therefore, to reach and to maintain effective therapy, repeated administrations are necessary. Unfortunately, frequent intravitreal injections increase the risk of endophthalmitis, damage to lens, retinal detachment. Moreover, some drugs provoke a local toxicity at their effective dose inducing side-effects and possible retinal lesions. This is the reason why new drug delivery systems, among which liposomes, have been developed to improve the intravitreal administration of drugs. Liposomes can reduce the toxicity and increase the residence time of several active molecules in the eye. In vivo, they can protect poorly-stable drugs such as peptides and nucleic acids from degradation. Successful reports have shown their potential for improving the treatment of retinitis induced by cytomegalovirus in human and more recently for the treatment of uveitis in rats. Moreover, recent preliminary studies about the trafficking of liposomes in ocular tissues and fluids following intravitreal injection attempted to elucidate their fate. All the data discussed in this review support the large interest raised by these colloidal carriers for intravitreal drug delivery.
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Abstract
BACKGROUND Intravitreal injection (IVI) with administration of various pharmacological agents is a mainstay of treatment in ophthalmology for endopthalmitis, viral retinitis, age-related macular degeneration, cystoid macular edema, diabetic retinopathy, uveitis, vascular occlusions, and retinal detachment. The indications and therapeutic agents are reviewed in this study. METHODS A search of the English, German, and Spanish language MEDLINE database was conducted. A total of 654 references spanning the period through early 2008 were individually evaluated. RESULTS The advantage of the IVI technique is the ability to maximize intraocular levels of medications and to avoid the toxicities associated with systemic treatment. Intravitreal injection has been used to deliver several types of pharmacological agents into the vitreous cavity: antiinfective and antiinflammatory medications, immunomodulators, anticancer agents, gas, antivascular endothelial growth factor, and several others. The goal of this review is to provide a detailed description of the properties of numerous therapeutic agents that can be delivered through IVI, potential complications of the technique, and recommendations to avoid side effects. CONCLUSION The IVI technique is a valuable tool that can be tailored to the disease process of interest based on the pharmacological agent selected. This review provides the reader with a comprehensive summary of the IVI technique and its multitude of uses.
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Affiliation(s)
- Gholam A Peyman
- Department of Ophthalmology and Vision Science, College of Medicine, University of Arizona, Tucson, Arizona 85351, USA.
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13
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Park SS, D'amico DJ. Advances in Antiviral Therapy for Cytomegalovirus Retinitis. Semin Ophthalmol 2009. [DOI: 10.3109/08820539309060207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Preparation, characterization, and in vivo evaluation of nanoliposomes-encapsulated bevacizumab (avastin) for intravitreal administration. Retina 2009; 29:699-703. [PMID: 19430280 DOI: 10.1097/iae.0b013e3181a2f42a] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Intravitreal injections can cause several ocular complications, including vitreous hemorrhage, endophthalmitis, retinal detachment, and cataract, and clearly repeated injections can multiply the risk of these complications. Bevacizumab is used for the treatment of different ocular diseases. For improvement of drug availability after intravitreal administration, in this study, liposomal bevacizumab as a novel drug delivery system was prepared and compared with conventional formulas in the market. METHODS Bevacizumab was encapsulated into liposomes via the dehydration-rehydration method. After reducing the size of liposome to the nanoscale, the final liposomal formulation was tested in an animal model. Left eyes of rabbits received liposomal bevacizumab and the right eyes were injected by soluble bevacizumab. The free drug concentration in aqueous humor and vitreous samples at Days 3, 7, 14, 28, and 42 after the injection was determined by enzyme-linked immunosorbent assay. RESULTS Mean concentration of free bevacizumab in the eyes that received liposomal bevacizumab compared with the eyes injected with soluble bevacizumab was 1 (48 versus 28 microg/mL) and 5 (16 versus 3.3 microg/mL) times higher at Days 28 and 42, respectively. Mean concentration of free bevacizumab in the aqueous humor of both injected eyes was almost the same at the different intervals. CONCLUSION The results of this study showed the beneficial effects of liposomes in prolonging the residency of bevacizumab in the vitreous.
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Patent Briefing. J Microencapsul 2008. [DOI: 10.3109/02652048809064171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Research into treatment modalities affecting vision is rapidly progressing due to the high incidence of diseases such as diabetic macular edema, proliferative vitreoretinopathy, wet and dry age-related macular degeneration and cytomegalovirus retinitis. The unique anatomy and physiology of eye offers many challenges to developing effective retinal drug delivery systems. Historically, drugs have been administered to the eye as liquid drops instilled in the cul-de-sac. However retinal drug delivery is a challenging area. The transport of molecules between the vitreous/retina and systemic circulation is restricted by the blood-retinal barrier, which is made up of retinal pigment epithelium and endothelial cells of the retinal blood vessels. An increase in the understanding of drug absorption mechanisms into the retina from local and systemic administration has led to the development of various drug delivery systems, such as biodegradable and non-biodegradable implants, microspheres, nanoparticles and liposomes, gels and transporter-targeted prodrugs. Such diversity in approaches is an indication that there is still a need for an optimized noninvasive or minimally invasive drug delivery system to the eye. A number of large molecular weight compounds (i.e., oligonucleotides, RNA aptamers, peptides and monoclonal antibodies) have been and continue to be introduced as new therapeutic entities. However, for high molecular weight polar compounds the mechanism of epithelial transport is primarily through the tight junctions in the retinal pigment epithelium, as these agents undergo limited transcellular diffusion. Delivery and administration of these new drugs in a safe and effective manner is still a major challenge facing pharmaceutical scientists. In this review article, the authors discuss various drug delivery strategies, devices and challenges associated with drug delivery to the retina.
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Affiliation(s)
- Kumar G Janoria
- University of Missouri-Kansas City, Department of Pharmaceutical Sciences, School of Pharmacy, 5005 Rockhill Road, Kansas City, MO 64110, USA
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Abstract
PURPOSE OF REVIEW New pharmacotherapies for posterior segment diseases of the eye have been recently introduced which use novel drug delivery methods. The various current and potential future methods will be discussed. RECENT FINDINGS Drug delivery systems have been developed which can provide controlled release of drug for potentially long periods of time. Ideal candidates for these devices are chronic conditions that require repeated local administration of drug, such as noninfectious intermediate or posterior uveitis, neovascular age-related macular degeneration, and persistent macular edema due to diabetic retinopathy or venous occlusive disease. Recently, Retisert (Bausch & Lomb, Rochester, New York, USA), a nonbiodegradable fluocinolone acetonide implant, was approved for use in noninfectious uveitis affecting the posterior segment and is currently in clinical trials for the treatment of macular edema. A biodegradable dexamethasone implant is currently in clinical trials for the treatment of uveitis and diabetic macular edema. SUMMARY With the development of therapeutic agents that require repeated administration comes a need for new strategies to improve safety and maximize efficacy. Novel drug delivery systems involving nonbiodegradable or biodegradable implants, microparticulates or nanoparticulates, liposomes, or transscleral iontophoresis may provide the solution.
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Affiliation(s)
- Jason Hsu
- Retina Service, Wills Eye Institute, Philadelphia, PA 19107, USA.
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Abstract
Developing an intraocular drug delivery system (DDS) is urgently needed because most vitreoretinal diseases are refractory to conventional pharmacological approaches; eye drops and systemically administered drugs cannot deliver therapeutic drug concentrations into vitreoretinal tissue. Intraocular DDSs address this problem. Intraocular sustained-drug release via implantable devices or injectable microparticles has been investigated to treat vitreoretinal diseases. A nonbiodegradable implant was first used in 1996 for cytomegalovirus retinitis secondary to the acquired immunodeficiency syndrome. Biodegradable implants, composed of hydrophilic or hydrophobic polymers, in the shape of rods, plugs, discs or sheets have been investigated. An injectable rod is presently being assessed in a Phase III trial to treat macular oedema secondary to diabetic retinopathy or branch-retinal vein occlusion. Intraocular DDSs using a biodegradable implant may soon be successfully used to treat serious intraocular disorders.
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Affiliation(s)
- Tsutomu Yasukawa
- Department of Ophthalmology, Nagoya City University Medical School, Aichi 467-8601, Japan.
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Abstract
This review outlines the applications of liposomal formulations in ophthalmology. In ophthalmology, liposomes have been used to treat disorders of both the anterior and posterior segments. These include dry eyes, keratitis, corneal transplant rejection, uveitis, endophthalmitis, and proliferative vitreoretinopathy. Liposomes also have shown promise as vectors for genetic transfection and monoclonal antibody-directed vehicles. Furthermore, heat-activated liposomes have spurred research in focal laser and heat-induced release of liposomal drugs and dyes for selective drug delivery. These techniques have been useful in selective tumor and neovascular vessel occlusion, angiography, and retinal and choroidal blood-flow studies. Although verteporfin is the only liposomal drug currently approved for use in the eye, the benefits of liposomes will likely be applied widely in all treatment, diagnostic, and research aspects of ophthalmology in the future.
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Affiliation(s)
- Shehab Ebrahim
- Department of Ophthalmology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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Yasukawa T, Ogura Y, Tabata Y, Kimura H, Wiedemann P, Honda Y. Drug delivery systems for vitreoretinal diseases. Prog Retin Eye Res 2004; 23:253-81. [PMID: 15177203 DOI: 10.1016/j.preteyeres.2004.02.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The eye has an environment that is specific unto itself in terms of pharmacokinetics: the inner and outer blood-retinal barriers separate the retina and the vitreous from the systemic circulation and vitreous body, which physiologically has no cellular components, occupies the vitreous cavity, an inner space of the eye, and reduces practical convection of molecules. Considering this, development of a drug delivery system (DDS) is becoming increasingly important in the treatment of vitreoretinal diseases not only to facilitate drug efficacy but also to attenuate adverse effects. The DDS has three major goals: enhances drug permeation (e.g., iontophoresis and transscleral DDS), controls release of drugs (e.g., microspheres, liposomes, and intraocular implants), and targets drugs (e.g., prodrugs with high molecular weight and immunoconjugates). Comprehensive knowledge of these should lead to development of innovative treatment modalities.
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Affiliation(s)
- Tsutomu Yasukawa
- Department of Ophthalmology, Nagoya City University Medical School, Aichi 467-8601, Japan.
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Abstract
Retinal drug delivery is a challenging area in the field of ophthalmic drug delivery. An ideal drug delivery system for the retina and vitreous humor has not yet been found, despite extensive research. Drug delivery to retinal tissue and vitreous via systemic administration is constrained due to the presence of a blood-retinal barrier (BRB) which regulates permeation of substances from blood to the retina. Although intravitreal administration overcomes this barrier, it is associated with several other problems. In recent years, transporter targeted drug delivery has become a clinically significant drug delivery approach for enhancing the bioavailabilities of drug molecules with poor membrane permeability characteristics. Various nutrient transporters, which include peptide, amino acid, folate, monocarboxylic acid transporters and so on, have been reported to be expressed on the retina and BRB. Prodrug derivatisation of drug molecules which target these transporters could result in enhanced ocular bioavailability. Highlighted in this review are various strategies currently employed for drug delivery to the posterior chamber, and novel opportunities that can be exploited to enhance ocular bioavailability of drugs.
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Affiliation(s)
- Sridhar Duvvuri
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 5005 Rockhill Road, Kansas City, MO 64110, USA
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Yasukawa T, Kimura H, Tabata Y, Ogura Y. Biodegradable scleral plugs for vitreoretinal drug delivery. Adv Drug Deliv Rev 2001; 52:25-36. [PMID: 11672873 DOI: 10.1016/s0169-409x(01)00192-2] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Intraocular controlled drug release is one way to facilitate drug efficacy and decrease side effects that occur with systemic administration. Vitreoretinal drug delivery with the biodegradable scleral plug has been investigated. The scleral plug, which is made of biodegradable polymers and drugs, can be implanted at the pars plana using a simple procedure, and it gradually releases effective doses of drugs with polymer biodegradation for several months. The release profiles of the drugs were dependent on the kind of polymers used, their molecular weights, and the amount of drug in the plug. The plugs are effective for treating vitreoretinal diseases such as proliferative vitreoretinopathy. The implantation site was replaced with connective tissue. Electroretinography and histologic studies revealed little retinal toxicity. This implantable scleral plug was supposed to be advantageous for diseases such as cytomegalovirus retinitis that respond to repeated intravitreal injections and for vitreoretinal disorders that require vitrectomy.
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Affiliation(s)
- T Yasukawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, 606-8507, Kyoto, Japan.
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Kunou N, Ogura Y, Honda Y, Hyon SH, Ikada Y. Biodegradable scleral implant for controlled intraocular delivery of betamethasone phosphate. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 51:635-41. [PMID: 10880111 DOI: 10.1002/1097-4636(20000915)51:4<635::aid-jbm11>3.0.co;2-o] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We evaluated nail-like, biodegradable scleral implants as a controlled intraocular delivery system of betamethasone phosphate (BP) for the treatment of chronic uveitis using pigmented rabbits. The scleral implants, which contained 10% and 25% of BP (weight 8.5 mg; length 5 mm), were made of poly (D,L-lactide-co-glycolide) (PLGA). In vivo release and retinal toxicity after implantation were also studied in pigmented rabbits. The in vitro release studies demonstrated the 10% and 25% BP-loaded scleral implants released BP in a biphasic release pattern for at least 1 month. The BP concentrations in the vitreous and the retina/choroid after application of scleral implants in pigmented rabbit eyes stayed within the concentration range capable of suppressing inflammatory responses for over 1 month. The BP concentration was greater in the retina/choroid than in the vitreous throughout the study. No substantial toxic reactions in the retina were observed by electroretinography. Our findings suggest that the BP-loaded scleral implant may be a promising device for treatment of chronic uveitis.
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Affiliation(s)
- N Kunou
- Department of Ophthalmology, Nagoya City University Medical School, Mizuho-ku, Nagoya 467-0001, Japan.
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Bochot A, Couvreur P, Fattal E. Intravitreal administration of antisense oligonucleotides: potential of liposomal delivery. Prog Retin Eye Res 2000; 19:131-47. [PMID: 10674705 DOI: 10.1016/s1350-9462(99)00014-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Antisense oligonucleotides are short synthetic fragments of genes that are able to inhibit gene expression after being internalized by cells. They can therefore be used as antiviral compounds particularly, for the treatment of ocular viral infections (i.e. Herpes simplex virus or Cytomegalovirus, CMV). Antisense oligonucleotides are however poorly stable in biological fluids and their intracellular penetration is limited. Although oligonucleotides are now currently used in therapeutics for the treatment of CMV by intravitreal injection (Vitravene) their main drawbacks impose to repeat the number of administrations which can be very harmful and damaging. A system that is able to permit a protection of oligonucleotides against degradation and their slow delivery into the vitreous would be more favorable for improving patient compliance. The use of liposomes for intravitreal administration can be very promising since these lipid vesicles are able to protect oligonucleotides against degradation by nucleases and they allow to increase the retention time of many drugs in the vitreous. In this review, the potentialities of liposomes for the intravitreal delivery of oligonucleotides will be discussed.
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Affiliation(s)
- A Bochot
- Université Paris XI, Centre d'études Pharmaceutiques, UMR CNRS 8612, Châtenay-Malabry, France
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Bourlais CL, Acar L, Zia H, Sado PA, Needham T, Leverge R. Ophthalmic drug delivery systems--recent advances. Prog Retin Eye Res 1998; 17:33-58. [PMID: 9537794 DOI: 10.1016/s1350-9462(97)00002-5] [Citation(s) in RCA: 423] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Eye-drops are the conventional dosage forms that account for 90% of currently accessible ophthalmic formulations. Despite the excellent acceptance by patients, one of the major problems encountered is rapid precorneal drug loss. To improve ocular drug bioavailability, there is a significant effort directed towards new drug delivery systems for ophthalmic administration. This chapter will focus on three representative areas of ophthalmic drug delivery systems: polymeric gels, colloidal systems, cyclodextrins and collagen shields. Hydrogels generally offer a moderate improvement of ocular drug bioavailability with the disadvantage of blurring of vision. In situ activated gel-forming systems are preferred as they can be delivered in drop form with sustained release properties. Colloidal systems including liposomes and nanoparticles have the convenience of a drop, which is able to maintain drug activity at its site of action and is suitable for poorly water-soluble drugs. Among the new therapeutic approaches in ophthalmology, cyclodextrins represent an alternative approach to increase the solubility of the drug in solution and to increase corneal permeability. Finally, collagen shields have been developed as a new continuous-delivery system for drugs that provide high and sustained levels of drugs to the cornea, despite a problem of tolerance. It seems that new tendency of research in ophthalmic drug delivery systems is directed towards a combination of several drug delivery technologies. There is a tendency to develop systems which not only prolong the contact time of the vehicle at the ocular surface, but which at the same time slow down the elimination of the drug. Combination of drug delivery systems could open a new directive for improving results and the therapeutic response of non-efficacious systems.
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Affiliation(s)
- C L Bourlais
- Laboratoire de Pharmacie Galénique, Biopharmacie et Pharmacie Clinique, Faculté de Pharmacie, Université de Rennes, France
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Abstract
This paper provides a comprehensive overview of the various approaches currently used in the development of ocular drug delivery systems for the treatment of ocular diseases in animals. It is obvious from the literature that most of the products that are currently available are derived from human medicine without consideration given to the differences which exist between the anatomy and physiology of the eye of various animal species which ultimately affect product design and performance. As a result, many of the products for animal use seem in many circumstances inappropriate for animal care. The article deals with some aspects of eye anatomy and physiology of different animals, and then provides an overview of the most commonly encountered pathologies. The paper then discusses the currently available drug products and finally reviews new delivery concepts. Several hundred references are included in the paper and provide access to further information on the subject.
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Miyamoto H, Ogura Y, Hashizoe M, Kunou N, Honda Y, Ikada Y. Biodegradable scleral implant for intravitreal controlled release of fluconazole. Curr Eye Res 1997; 16:930-5. [PMID: 9288455 DOI: 10.1076/ceyr.16.9.930.5042] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To evaluate the feasibility of using a biodegradable polymeric scleral implant containing fluconazole (FLCZ), a bis-triazole antifungal agent, as a potential intravitreal-controlled drug delivery system. METHODS The scleral implants, loaded with 10, 20, 30, and 50% FLCZ, were prepared with biodegradable polymers of poly (DL-lactide-co-glycolide). Those with all loading doses were used for the in vitro release studies; those with 30% FLCZ were used for the intravitreal release studies in pigmented rabbits. The in vitro and in vivo release rates of FLCZ from the implants were measured periodically with spectrophotometry and high performance liquid chromatography, respectively. The effects of the implants on ocular tissues were evaluated ophthalmoscopically, histologically, and electrophysiologically. RESULTS The scleral implants loaded with 10, 20, and 30% doses gradually released FLCZ over 4 weeks in vitro; those with 50% FLCZ released most of the drug in one week. FLCZ concentration in the rabbit vitreous remained within the 99% inhibitory concentration for Candida albicans for 3 weeks after implantation. The scleral implant gradually biodegraded, and it disappeared by 4 months after implantation. The electrophysiologic and histopathologic findings demonstrated no substantial toxic reactions in the ocular tissues. CONCLUSION The current study suggests that a biodegradable, polymeric scleral implant containing FLCZ may be a promising intravitreal drug delivery system to treat fungal endophthalmitis.
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Affiliation(s)
- H Miyamoto
- Department of Ophthalmology and Visual Science, Graduate School of Medicine, Kyoto University, Japan
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Hashizoe M, Ogura Y, Takanashi T, Kunou N, Honda Y, Ikada Y. Biodegradable polymeric device for sustained intravitreal release of ganciclovir in rabbits. Curr Eye Res 1997; 16:633-9. [PMID: 9222079 DOI: 10.1076/ceyr.16.7.633.5063] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE A scleral plug made of biodegradable polymer implanted at the pars plana was evaluated to determine its ability to control the intravitreal release of ganciclovir. METHODS Scleral plugs containing 25% ganciclovir were prepared with poly(lactic-glycolic acid) (molecular weight, 121 kDa). The release of ganciclovir was evaluated in vitro by spectrophotometry. In vivo intravitreal ganciclovir concentrations were measured by high performance liquid chromatography following plug implantation in pigmented rabbits. The biocompatibility of the device was determined by indirect ophthalmoscopy, electroretinography, and light and electron microscopy. RESULTS The in vitro study showed that the plug released ganciclovir throughout a 10-week period. The in vivo study demonstrated that the plugs maintained the drug concentration in the vitreous in a therapeutic range adequate to treat cytomegalovirus (CMV) retinitis for 12 weeks. No significant retinal toxicity was observed. CONCLUSIONS This study demonstrated that this drug delivery system can potentially be useful to treat CMV retinitis.
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Affiliation(s)
- M Hashizoe
- Department of Ophthalmology and Visual Science, Faculty of Medicine, Kyoto University, Japan
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30
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Le Bourlais C, Chevanne F, Ropert P, Bretagne G, Acar L, Zia H, Sado PA, Needham T, Leverge R. Release kinetics of liposome-encapsulated ganciclovir after intravitreal injection in rabbits. J Microencapsul 1996; 13:473-80. [PMID: 8808783 DOI: 10.3109/02652049609026032] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This study was undertaken to establish experimentally whether the intravitreal application of liposomally-entrapped ganciclovir could prolong intraocular therapeutic levels when it is compared to the intravitreal injection of a simple solution of the drug. New Zealand white rabbits were given an intravitreal injection of the drug solution and of liposome-encapsulated ganciclovir. The intravitreal clearance of ganciclovir was determined after a single injection of either the drug solution (200 micrograms/0.1 mL) or the liposomally-entrapped (with 41% load; 82 micrograms drug load and 118 micrograms free) ganciclovir. The ganciclovir vitreal concentrations were measured at various time intervals for a period up to 43 days using an HPLC method. The results of this study clearly demonstrated that prolonged intravitreal drug levels (above the mean inhibitory dose of cytomegalovirus of 1 microgram/mL) after administration of the liposome-entrapped ganciclovir and estimated to continue beyond 30-43 days. The injection of the 200 micrograms/0.1 mL of drug solution showed a mean vitreous concentration which was higher than the ID50 only for 55 h. The disappearance rate constant for the liposome-encapsulated injections was approximately 22 x slower than simple drug solution injections (controls). No evidence of retinal toxicity was found by clinical or light microscopy examination of the treated eyes.
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Affiliation(s)
- C Le Bourlais
- Laboratoire de Pharmacie galénique, Faculté de Pharmacie, Université de Rennes, France
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31
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Controlled intraocular delivery of ganciclovir with use of biodegradable scleral implant in rabbits. J Control Release 1995. [DOI: 10.1016/0168-3659(95)00074-i] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Akula SK, Ma PE, Peyman GA, Rahimy MH, Hyslop NE, Janney A, Ashton P. Treatment of cytomegalovirus retinitis with intravitreal injection of liposome encapsulated ganciclovir in a patient with AIDS. Br J Ophthalmol 1994; 78:677-80. [PMID: 7947546 PMCID: PMC504904 DOI: 10.1136/bjo.78.9.677] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To study its safety and efficacy in treating cytomegalovirus (CMV) retinitis, an AIDS patient received an intravitreal injection of liposome encapsulated ganciclovir in the right eye. The left eye served as a control, receiving intravitreal free ganciclovir. The right eye showed no retinal haemorrhages or detachment; however, vision declined initially, stabilising later. Weekly examination showed neither progression of the CMV retinitis nor new lesions in the right eye. The left eye showed reactivation of old CMV retinitis. Liposome encapsulated ganciclovir reduced the number of intravitreal injections, stabilising CMV retinitis, and warrants further study.
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Affiliation(s)
- S K Akula
- Department of Medicine, Tulane University Medical Center, New Orleans, LA
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Rahimy MH, Peyman GA, Chin SY, Golshani R, Aras C, Borhani H, Thompson H. Polysulfone capillary fiber for intraocular drug delivery: in vitro and in vivo evaluations. J Drug Target 1994; 2:289-98. [PMID: 7858954 DOI: 10.3109/10611869409015909] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Studies were conducted to investigate the usefulness of polysulfone capillary fiber (PCF) as a drug delivery device for intraocular applications. Carboxyfluorescein (CF) was used as a model drug to prepare PCF-dye devices for both in vitro and in vivo kinetic studies. For the in vitro study, PCF-CF devices were incubated in 0.1 M phosphate buffer, pH 7.4 at 37 degrees C, and CF release was quantified at various times up to 5 weeks. In vitro results indicated a bi-phasic, sustained-release profile of CF from the PCF device for over 30 days. PCF-CF devices released 5% and 10% of their initial CF contents by the first and second day following incubation, respectively. By 10 days after incubation, approximately 50% of the dye content was released from the PCF-CF devices. The rate of dye release decreased thereafter, such that 65% and 90% of CF was released by 17 and 28 days after incubation, respectively. In a subsequent study, the in vivo kinetics of the PCF-CF device were determined in the rabbit eye. PCF-dye devices were prepared with the following CF formulations: 1) microsphere-incorporated CF; 2) lyophilized liposome-encapsulated CF; or 3) micronized CF powder. A PCF-dye device was implanted in the vitreous cavity, and fluorophotometry from the retina to the anterior chamber was performed at various times up to 45 days to quantify fluorescein level. At the conclusion of the study, eyes were enucleated and examined for histopathology. The time-course study showed fluorescein level for up to 45 days in the vitreous. The midvitreous concentration-time profile indicated a CF t1/2 of 10 and 30 days for the PCF-CF powder and PCF-CF liposome preparation, respectively. In contrast, the PCF device prepared with microsphere-incorporated CF showed fluorescein level with a t1/2 of less than one week in the vitreous. Histological examination of the eyes implanted with PCF or PCF-dye device showed no sign of ocular toxicity. Collectively, these results indicated that the PCF device is biocompatible and may be useful for the extended release of drugs in the posterior segment of the eye.
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Abstract
Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.
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Affiliation(s)
- S A Teich
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, New York
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Díaz-Llopis M, Martos MJ, España E, Cervera M, Vila AO, Navea A, Molina FJ, Romero FJ. Liposomally-entrapped ganciclovir for the treatment of cytomegalovirus retinitis in AIDS patients. Eperimental toxicity and pharmacokinetics, and clinical trial. Doc Ophthalmol 1992; 82:297-305. [PMID: 1339115 DOI: 10.1007/bf00161017] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Treatment of retinitis by cytomegalovirus (CMV) in AIDS patients requires frequent repetitive injections of intravitreal ganciclovir (GCV). This study was undertaken to establish experimentally whether the intravitreal application of liposomally-entrapped GCV could prolong intraocular therapeutic levels when compared with the intravitreal injection of free GCV, and the clinical effectiveness of this approach in AIDS patients. Intraocular concentration of GCV was determined by means of an ELISA test in rabbit vitreous 2, 3, 7, and 14 days after a single intravitreal injection of either different doses of the free drug (0.2-20 mg) or 1 mg of liposomally-entrapped GCV. After 72 h, only the vitreous of rabbits injected with doses of free GCV greater than or equal to 5 mg showed therapeutic levels of the drug; no GCV was detected after 72 h with any of the doses applied. Moreover, the microscopic study revealed GCV-induced damage in retinal structures in the animals injected with a free GCV dose greater than or equal to 15 mg. Intravitreal injection to rabbits of 1 mg of liposomally-encapsulated GCV showed no retinal toxicity at any of the time points studied, and therapeutic levels were detected up to 14 days after injection (4.67 +/- 0.39 microgram/ml). Five AIDS patients suffering CMV retinitis were injected with 0.5 mg of liposomally-entrapped GCV (2 mg of lecithin). Complete remission of the CMV retinitis was observed already at the third injection of 0.5 mg GCV (one per week) and relapse did not occur during the 2-4 month follow-up of the patients. In view of the results presented, it can be concluded that intravitreal injection of liposomally-encapsulated GCV increases the time period required for reinjections in the treatment of CMV retinitis.
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Affiliation(s)
- M Díaz-Llopis
- Department of Surgery, School of Medicine and Dentistry, University of Valencia, Spain
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Khoobehi B, Stradtmann MO, Peyman GA, Aly OM. Clearance of Sodium Fluorescein Incorporated Into Microspheres From the Vitreous After Intravitreal Injection. Ophthalmic Surg Lasers Imaging Retina 1991. [DOI: 10.3928/1542-8877-19910301-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Schulman JA, Peyman GA. Management of Viral Retinitis. Ophthalmic Surg Lasers Imaging Retina 1988. [DOI: 10.3928/1542-8877-19881201-13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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40
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Khoobehi B, Peyman GA, McTurnan WG, Niesman MR, Magin RL. Externally triggered release of dye and drugs from liposomes into the eye. An in vitro and in vivo study. Ophthalmology 1988; 95:950-5. [PMID: 3174046 DOI: 10.1016/s0161-6420(88)33070-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Temperature-sensitive liposomes were made with carboxyfluorescein (CF) (100 mM) entrapped in the aqueous compartment. This liposome dye system was used in vitro to evaluate the feasibility of using microwaves as a triggering mechanism for the release of drugs in the anterior chamber of the eye. The in vitro study demonstrated that CF can be released from liposomes in response to a localized temperature rise induced by microwave irradiation. In an in vivo study in rabbits, CF and the antineoplastic agent, cytosine arabinoside, were administered intravenously and selectively released by increasing the temperature of the ciliary body with microwaves. In the eyes receiving liposome-encapsulated dye, the average concentration of CF in the anterior chamber of the heated eyes was 8.0 times higher than in the contralateral unheated control eyes. In the eyes receiving liposome-encapsulated drug, the average concentration of cytosine arabinoside in the aqueous of the heated eyes was 4.1 times higher than the concentration in the contralateral unheated control eyes. The importance of this finding lies in the potential for a new method of targeting the delivery of dyes and drugs to specific sites in the eye.
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Affiliation(s)
- B Khoobehi
- LSU Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans
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41
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Peyman GA, Charles HC, Liu KR, Khoobehi B, Niesman M. Intravitreal liposome-encapsulated drugs: a preliminary human report. Int Ophthalmol 1988; 12:175-82. [PMID: 3265937 DOI: 10.1007/bf00130002] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intravitreal liposome-encapsulated antibiotics and antiviral drugs were used in patients with acute toxoplasmosis retinochoroiditis, presumed propionibacterium acne endophthalmitis after cataract surgery, and presumed cytomegalovirus retinitis associated with AIDS. A single intravitreal dose was effective in the treatment of all the conditions. Intravitreal liposomes may prove to be an advantageous drug delivery system for the treatment of chronic intraocular inflammatory disorders.
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Affiliation(s)
- G A Peyman
- LSU Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans
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