Design and Characterization of Bioadhesive In-Situ Gelling Ocular Inserts of Gatifloxacin Sesquihydrate

Background and purpose of the study: Several polymeric systems have been used to fabricate ocular inserts for better ocular bioavailability and retention to drug of which gelling systems have shown advantages of convenient administration and increased contact time. The purpose of the present study was to develop a bioadhesive in-situe gelling ocular insert of Gatifloxacin using polymeric system of sodium alginate as gelling and chitosan as bioadhesive agent. Polymeric ocular inserts of Gatifloxacin sesquehydrate (GS) were composed using sodium alginate and chitosan with glycerin as plasticizer by solvent casting method. The ocular inserts were investigated for physicochemical properties (thickness, weight variation, folding endurance and surface pH), mechanical strength (tensile strength, elongation at break), swelling index, and bioadhesion parameters. In vitro release studies were carried using a fabricated donor-receptor compartment model. Cumulative drug released from the formulation ranged from 95-99% within 8-12h. The formulation D (2% sodium alginate and 1% chitosan) sustained the drug release for the longest period of time (12h). Zero-order release of the drug was from optimized formulation D. A high correlation coefficient (r=0.9845) was recorded between in vitro and in vivo drug release. Gatifloxacin sesquehydrate inserts have appreciable film forming properties and were found to posses good antimicrobial efficacy.