Effect of Phenylephrine Hydrochloride on Betamethasone Side Effect in Relation to Viscosity of Ophthalmic Preparations II - Gel-State

Abstract

AbstractCombination preparations of betamethasone and phenylephrine hydrochloride were prepared in the form of ophthalmic gels based on polye thylene glycols, PEG, a carboxyvinyl polymer (carborner 934) or methylcellulose. The intraocular pressure, IOP, was followed after the application of the se gels to the rabbit eye. Three parameters have been utilized to assess the performance of combination preparations of the two drugs. These are the area under the curve, AUC, the maximum response, MR, and the duration of side effect (increased the IOP). It was found that the inclusion of phenyle phrine hydrochloride in the gel reduces, to marked extent, viz. 80-90%, the AUC compared to the corresponding gel devoid of phenylephrine hydrochloride, and that,∼60% reduction in the duration of betamethasone side effect with regard to the IOP. The most effective gel system appeared to be methylcellulose based gel.