Novel Approach and Recent Advancement In-Situ Gel as Smart Carriers for Controlled Drug Delivery via Ophthalmic Route

Abstract: Research in ocular delivery of medication has both challenging and promising opportunities for the pharmaceutical sector. Present ocular delivery methods of drugs, including ointments, solutions, and suspensions, have a number of limitations, such as rapid elimination from the precorneal area, high variation in efficacy, and the risk of blurred vision. These disadvantages underscore the need for the introduction of more effective drug delivery systems. Research on ocular drug delivery has increased significantly in the past years, resulting in the use of numerous standard formulation forms, such as ointments and eye drops. One big drawback of the two formulations is the fast expulsion of the deposited dose through the action of blinking eyelids as well as the excretion of tear fluid. To counter this, in situ, gelling systems have been created that minimize drainage and prolong the period of contact with the ocular tissues and cornea. The formulations in these systems go through a sol-to-gel change due to conditions in the environment, for example, temperature, ionic strength, and pH. The transitions are usually triggered by the common polymers sodium alginate and high-performance methylcellulose. These preparations can be tested for any one of a number of properties, such as but not limited to clarity, ocular irritancy, texture, isotonicity, sterility, gel strength, gelling capacity, gelling time, ex-vivo release, in vitro drug release, stability, in vivo retention, and absorption.