Formulation Development and Evaluation of an in Situ Ophthalmic Gelling System of Brimonidine Tartrate and Timolol Maleate for the Treatment of Glaucoma

Abstract

The present study involved formulation of an in situ gelling system of brimonidine tartrate and timolol maleate for the treatment of glaucoma. Carbopol® 980 NF, xanthum gum and hydroxypropyl methylcellulose K4 M were used as polymers. The prepared in situ gelling systems were evaluated for clarity, appearance, texture analysis, pH, viscosity, rheological properties, in vitro gelation, isotonicity, drug content uniformity, in vitro release studies, microbiological evaluation, ex vivo release studies and stability testing. The results of the attenuated total reflectance spectroscopy and differential scanning calorimetry studies confirmed that there is no incompatibility between the drugs and the excipients. The formulations exhibited pseudoplastic rheology and formulation 3 showed the highest release of both the drugs from the formulation. The stability studies showed that the formulation was stable over the given period of time. Thus, it is evident that the in situ gelling system is a promising drug delivery system for the treatment of glaucoma.