A Recent Overview: In Situ Gel Smart Carriers for Ocular Drug Delivery

Abstract

Delivery of the drug to the ocular area is blocked by the protective layers covering the eyes; it has always been a major problem to find effective bioavailability of the active drug in the ocular area due to the short duration of precorneal majority ocular stay. Direct delivery systems combine as well as oil, solution, and suspension, as a result, many delivery systems are not able to effectively treat eye diseases. Many works have been done and are being done to overcome this problem one of which is to use in-situ to build polymeric systems. Ocular In-situ gelling systems are a new class of eye drug delivery systems that are initially in solution but are quickly transformed into a viscous gel when introduced or inserted into an ocular cavity where active drugs are released continuously. This sol-to-gel phase conversion depends on a variety of factors such as changes in pH, ion presence, and temperature changes. Post-transplanting gel selects viscosity and bio-adhesive properties, which prolongs the gel's stay in the ocular area and also releases the drug in a long and continuous way unlike conventional eye drops and ointments. This review is a brief overview of situ gels, the various methods of in situ gelling systems, the different types of polymers used in situ gels, their gel-based methods, and the polymeric testing of situ gel.
 Keywords: In-situ gel, Polymers, and ion triggered in-situ gel, Mechanism, Evaluation parameters

Novel Biomaterials in Glaucoma Treatment

“…Topical eye drops, ointments, and oral medications are commonly used to decrease IOP; however, they have limitations, including poor patient compliance and inadequate bioavailability [33]. To increase bioavailability and improve patient compliance, advanced drug delivery mechanisms, such as liposomes, microneedles, niosomes, dendrimers, ocular inserts, nanoparticles, and injectable hydrogels have been described in the literature [34,35]. In situ hydrogels can potentially act as delivery vehicles for nutrients, oxygen, and drugs in a targeted area [36].…”

Intravitreal Injectable Hydrogels for Sustained Drug Delivery in Glaucoma Treatment and Therapy

“…Pharmaceutical therapeutics for the management of glaucoma through topical eye drops, ointments, and oral medications reduce elevated IOP; however, there are limitations, including low patient compliance and insufficient bioavailability [16]. To elevate bioavailability and improve patient compliance, advanced drug delivery mechanisms such as liposomes, microneedles, niosomes, dendrimers, ocular inserts, nanoparticles, and injectable hydrogels should be used [17].…”