Design, formulation, and evaluation of novel sustain release bioadhesive in-situ gelling ocular inserts of ketorolac tromethamine

Introduction: The eye is an interesting organ. The tear flow and blinking reflex maintains a good environment and removes foreign material from the eye. 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. Aim: The purpose of the present study was to develop a bioadhesive in-situ gelling ocular insert of Ketorolac tromethamine using polymeric system of sodium alginate as gelling and chitosan as bioadhesive agent. Methods: Various batches of ketorolac tromethamine bioadhesive in-situ gelling ocular inserts were prepared using sodium alginate and chitosan with glycerin as a plasticizer by solvent casting method. The formulated bioadhesive in-situ gelling ocular insert were then evaluated for physical appearance, thickness, weight variation, folding endurance, percentage moisture loss, percentage moisture absorption, tensile strength, percentage flatness, bioadhesive strength, force of adhesive, drug content, in vitro drug release, sterility test, in vitro antimicrobial efficacy, and stability study. Results: The formulation F4 was shown 98.62 % drug release at the end of 12 h. Hence that F4 formulation was maximum sustain drug release than other formulation and also optimum and better result of physicochemical properties than other formulation. This optimized formulation was subjected to sterility and stability test. There was no evidence of microbial growth and hence the ocular insert passed the sterility test and there was no significant change in the physicochemical properties from 0th to 30th day. Hence, the formulation was found to be stable. Conclusion: The said promising formulation (F4) would be able to offer benefits such as increase residence time, prolonged drug release, reduction in frequency of administration and thereby definitely prove to improve the patient compliance.