In Situ Gel-Based Ocular Delivery: A Comprehensive Review

AbstractIn situ gel systems have gained considerable attention as innovative ocular drug delivery platforms,offering distinct advantages over conventional eye drops. Reported studies highlight their ability toremain liquid during instillation and undergo sol–gel transition upon exposure to ocular stimuli,thereby prolonging precorneal residence and sustaining drug release. Literature findings confirmpseudoplastic rheology, strong mucoadhesion, and enhanced corneal penetration, which collectivelyimprove bioavailability and reduce dosing frequency. Antimicrobial evaluations demonstratemaintained or enhanced activity against Gram-positive and Gram-negative pathogens, includingresistant strains, while biocompatibility assessments reveal excellent ocular tolerability withnegligible systemic absorption. Stability studies under accelerated and ambient conditions furthervalidate the long-term integrity of these formulations. Collectively, evidence from previousresearch establishes in situ gels as safe, effective, and patient-friendly systems for managing ocularinfections such as conjunctivitis, keratitis, and postoperative complications, underscoring theirpotential as next-generation ophthalmic drug delivery platforms.