Thermosensitive Brinzolamide in situ Gel Nanoemulsions, in vitro and ex vivo Evaluation

Abstract

Brinzolamide (BZ) is a carbonic anhydrase inhibitor with selectivity and affinity for the carbonic anhydrase type II isoenzyme that administrated topically as an ophthalmic suspension for reducing intraocular pressure. In this study, BZ in situ gel nanoemulsions (NEs) were developed and evaluated for transcorneal permeation via the bovine corneal membrane. The spontaneous emulsification method was employed to prepare BZ in situ gel NEs. Various physicochemical characteristics, including particle size, polydispersity index, pH, refractive index, and viscosity, were evaluated. Accelerated physical stability and in vitro drug release, as well as transcorneal permeation studies was performed by applying the Franz-type diffusion cells. Thermosensitive BZ in situ gel NEs with desired physicochemical features and sustained release profiles were designed in the current study. Optimized Formulations exhibited physical stability under different conditions. The transcorneal permeation of formulations was higher than that of suspension, especially for F3b formulation. According to the present in vitro and ex vivo evaluations, it is concluded that in situ gel NEs could be a topical administration of BZ as a suitable ocular drug delivery system.