A review: In-situ gel drug delivery system

The eye is the body's most delicate organ. Pharmaceutical scientists find that designing ocular drug delivery systems is the most difficult because only 5% of administered drugs reach the eye due to the complex anatomical structure of the eye, the cornea's small absorptive surface and low transparency, the cornea's lipophilicity, pre-keratitis (from nasolacrimal drainage), the drug's bonding with proteins in tear fluid, blinking, and the conjunctival sac's low capacity, all of which limit the entry of drug molecules at the site of action and ultimately result in suboptimal ocular therapy. Considerable research is being done on developing more advanced drug delivery methods for ocular administration in an attempt to increase the bioavailability of ophthalmic medications. These innovative drug delivery methods have many benefits over traditional ones, including better release profiles that boost drug delivery efficiency and lower drug toxicity. Numerous studies in this field support the idea that in situ gelling devices can be helpful for the transport of drugs into the eyes. Drug delivery systems known as "in situ gel-forming systems" are in solution before being supplied to the body, but thereafter go through a process called "in situ gelation" to form a gel in response to an external stimulus like pH or temperature. A brief overview of in situ gels, several methods for in situ gelling systems, types of polymers utilized in in-situ gels, their mechanisms of gel formation, and an assessment of polymeric in situ gel are all included in this review.