Formulation Development And Evaluation Of A Thermo-Sensitive In-Situ Gel Incorporating Allium Sativum (Allicin) Infused Chitosan Nanoparticles Against Acanthamoeba Keratitis

Abstract

Acanthamoeba keratitis (AK) is a severe, vision-threatening corneal infection predominantly affecting contact lens users. Current treatment regimens require prolonged administration and are often associated with toxicity and poor patient compliance due to limited ocular bioavailability. Allicin, a bioactive sulfur-containing compound derived from garlic, exhibits potent antimicrobial and anti-amoebic activity but suffers from instability and rapid degradation under physiological conditions. The present study aimed to formulate and evaluate a thermosensitive in situ gel incorporating allicin-loaded chitosan nanoparticles for enhanced ocular delivery against Acanthamoeba keratitis. Allicin-loaded chitosan nanoparticles were prepared by ionic gelation using sodium tripolyphosphate (TPP) and characterized for particle size, zeta potential, entrapment efficiency, and morphology. The optimized nanoparticles were incorporated into a poloxamer-based thermosensitive in situ gel. The formulation was evaluated for pH, gelation temperature, viscosity, drug content, in vitro drug release, and anti-amoebic activity. The optimized formulation demonstrated nanosized particles with high entrapment efficiency, appropriate gelation at ocular temperature, and sustained drug release up to 24 hours. Enhanced anti-amoebic activity was observed compared to free allicin. The developed formulation shows potential as a promising ocular drug delivery system for the management of Acanthamoeba keratitis.