Preparation and In Vitro/In Vivo Evaluation of Antihistaminic Ocular Inserts

The present study aims to prepare ocular inserts of cetirizine hydrochloride, an antihistamine used to treat allergic conjunctivitis, allergic rhinitis, uveitis and urticaria. Solvent casting method was used to prepare inserts of hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) as film forming polymers, and polyethylene glycol (PG) and glycerin were used as plasticizers. Various physicochemical parameters of six ocular insert compositions were evaluated, including swelling behavior and in vitro drug release and kinetics. Formulation F4 showed results of in vitro studies in most appropriate range, with sustained drug release (99.12% at 210 min) following non-fickian diffusion. Drug - polymer compatibility study verified no chemical interaction between the drug and polymer. Therefore, formulation F4 was selected for in vivo studies in albino rabbits. The values of C-max, AUC, and T-max of formulation F4 were 478.70 ng/mL, 3013.58 ng/(mL h), and 2.3 h, respectively. Ocular inserts of cetirizine hydrochloride provide a valuable alternative for the treatment of ocular inflammatory diseases as these formulations ensure sustained drug release and increased residence time.