The major challenge faced by today's pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration,especially for the ...The major challenge faced by today's pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration,especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal,dynamic and static ocular barriers. Also,therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades,ocular drug delivery research acceleratedly advanced towards developing a novel,safe and patient compliant formulation and drug delivery devices/techniques,which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also,it includes development of conventional topical formulations such as suspensions,emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand,for posterior ocular delivery,research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreo-retinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topicaldrops. Also,these novel devices and/or formulations are easy to formulate,no/negligibly irritating,possess high precorneal residence time,sustain the drug release,and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments. Also,recent developments with other ocular drug delivery strategies employing in situ gels,implants,contact lens and microneedles have been discussed.展开更多
Macular edema such as diabetic macular edema(DME) and diabetic retinopathy are devastating back-of-theeye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior oc...Macular edema such as diabetic macular edema(DME) and diabetic retinopathy are devastating back-of-theeye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static(corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers(bloodretinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.展开更多
The eye is a complex organ made up of diversifed cells with specifed functions. Presence of anatomical, physi-ological and physiochemical barriers make it diffcult to deliver drugs in therapeutic amounts at intended s...The eye is a complex organ made up of diversifed cells with specifed functions. Presence of anatomical, physi-ological and physiochemical barriers make it diffcult to deliver drugs in therapeutic amounts at intended sites. To overcome these, drug delivery scientists have fol-lowed two distinct yet complimentary approaches. The frst involves using alternate delivery routes to conven-tional ones allowing for more direct access to intended target sites. Second approach involves development of novel drug delivery systems providing better perme-ability, treatability and controlled release at target site. Combination of both these approaches are being uti-lized and optimized in order to achieve optimal therapy with minimal adverse effects.展开更多
文摘The major challenge faced by today's pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration,especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal,dynamic and static ocular barriers. Also,therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades,ocular drug delivery research acceleratedly advanced towards developing a novel,safe and patient compliant formulation and drug delivery devices/techniques,which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also,it includes development of conventional topical formulations such as suspensions,emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand,for posterior ocular delivery,research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreo-retinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topicaldrops. Also,these novel devices and/or formulations are easy to formulate,no/negligibly irritating,possess high precorneal residence time,sustain the drug release,and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments. Also,recent developments with other ocular drug delivery strategies employing in situ gels,implants,contact lens and microneedles have been discussed.
文摘Macular edema such as diabetic macular edema(DME) and diabetic retinopathy are devastating back-of-theeye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static(corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers(bloodretinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.
文摘The eye is a complex organ made up of diversifed cells with specifed functions. Presence of anatomical, physi-ological and physiochemical barriers make it diffcult to deliver drugs in therapeutic amounts at intended sites. To overcome these, drug delivery scientists have fol-lowed two distinct yet complimentary approaches. The frst involves using alternate delivery routes to conven-tional ones allowing for more direct access to intended target sites. Second approach involves development of novel drug delivery systems providing better perme-ability, treatability and controlled release at target site. Combination of both these approaches are being uti-lized and optimized in order to achieve optimal therapy with minimal adverse effects.
