Sustained Release Bioadhesive Ocular Inserts of Olopatadine Hydrochloride: Formulation and Characterization

Abstract:

Objective: To develop bioadhesive ocular inserts of Olopatadine hydrochloride for treating the allergic eye conditions with sustained ocular delivery which will reduce dosing frequency. Methods: Matrix type ocular inserts were prepared by the solvent casting technique using teflon coated petri plates and characterized in vitro for drug release studies. Nine formulations were prepared having different ratios of polymers such as carbopol 980P, HPMC K4M and NaCMC (90:10, 70:30 and 50:50) and optimized. All the formulations were evaluated for thickness, weight variation, folding endurance, drug content uniformity, in vitro release study, bio/mucoadhesion studies, surface pH, swelling index, % moisture absorption, % moisture loss, release kinetics, histological study and stability study. Results: The optimized formulation ‘F5’ containing polymers Carbopol 980P and HPMC K4M in the ratio of 70:30 was selected on the basis of drug release studies. The formulation F5 was found to act as bio/mucoadhesive insert with sustained drug release by increasing residence time in the eye. Conclusion: The prepared inserts showed sustained drug release by increased residence time achieved through bioadhesion and thus may overcome the drawbacks of eye drops.

Key words: Olopatadine hydrochloride, Ocular inserts, Solvent casting, Bioadhesive, Drug release.