Comparative in-vitro transcorneal permeation studies of aqueous drop of esmolol HCl through excised goat, sheep, and buffalo corneas

The present work focuses to evaluate the effect of formulation factors transcorneal permeation of aqueous drop of esmolol HCL through freshly excised goat, sheep, and buffalo corneas. Effect of concentration of esmolol HCl in aqueous solution on permeation of drug through excised goat, sheep, and buffalo corneas was study. Esmolol HCL ophthalmic solutions of different concentrations (pH 7.2) or 0.5% (w/v) solutions of different pH or 0.5% solutions (pH 7.2) containing different preservatives were made. Franz diffusion was used for measuring the drug permeated in the receptor by spectrophotometry at 280 nm, after 120 minutes. Compared with control formulation, esmolol HCL 0.5 %( w/v) solution at pH 7.2 containing benzalkonium chloride (0.01% w/v) in the formulation increased permeation to the maximum with all the corneas and the apparent permeability coefficient was found to be maximum 9.85±0.4 on goat cornea. The results of the ophthalmic aqueous drop optimized formulation containing BAC,control formulation (without BAC) and marketed cardioselective eye drop betoptic S (betaxolol HCl) through paired corneas showed near bit same result. It can be accomplished that from the present studies increase in concentration of esmolol HCL in aqueous drop causes a disproportionate increase in permeation.