In situ gelling systems for ocular drug delivery

• Published in: Journal of controlled release Vol. 371; pp. 67 - 84
• Main Authors: Ahmed, Bakr, Jaiswal, Srishty, Naryal, Srishti, Shah, Rohan M., Alany, Raid G., Kaur, Indu Pal
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2024
• Subjects: Bioavailability; Ophthalmic; Polymer; Topical; Ophthalmic; Patent; Polymer; Topical; Bioavailability
• ISSN: 0168-3659; 1873-4995; 1873-4995
• DOI: 10.1016/j.jconrel.2024.05.031

In situ gelling systems represent a burgeoning paradigm in ocular drug administration, addressing intrinsic challenges posed by extant ocular formulations, such as compromised bioavailability and constraints in traversing the corneal barrier. This systematic review endeavours to comprehensively examine the contemporary landscape of research in this domain, focusing on the nuanced capabilities of in situ gelling systems to optimize drug delivery and enhance therapeutic outcomes, without much technological complexity. Employing a meticulous search strategy across diverse databases for publications and patents spanning the years 2015 to 2023 a total of 26 research papers and 14 patents meeting stringent inclusion criteria were identified. Synthesizing the collective insights derived from these investigations, it becomes evident that in situ gelling systems confer an ability to protract the residence time of formulations or active pharmaceutical ingredients (APIs) within the ocular milieu. This sustained presence engenders extended drug release kinetics, thereby fostering improved patient compliance and mitigating the proclivity for side effects attendant to frequent dosing. These salutary effects extend to diminished systemic drug absorption, augmented ocular bioavailability, and the prospect of reduced dosing frequencies, thereby amplifying patient adherence to therapeutic regimens. Intriguingly, the protective attributes of in situ gelling systems extend to the establishment of an ocular surface barrier, thereby abating the susceptibility to infections and inflammatory responses. In summation, this review underscores the auspicious potential of in situ gelling systems as a transformative approach to advancing ocular drug delivery, warranting sustained research endeavours and developmental initiatives for the betterment of global patient outcomes. [Display omitted] •In situ gels for ocular delivery offer simple alternative to conventional low performing drops•Various polymer and polymer combinations are used for in situ gelling, each with distinct mechanism and advantages.•Gelling upon application enhances drug retention and improves ocular bioavailability.•In situ gel-forming systems represent advanced ocular drug delivery, with enhanced therapeutic outcomes for eye disorders.•This review covers recent research and patents, focusing on ophthalmic applications of in situ gels.