In vitro and in vivo evaluation under finite conditions of a transdermal oil-in-water type emulsified formulation of propiverine hydrochloride.

A transdermal oil-in-water type emulsified formulation containing propiverine hydrochloride, used for treatment of an overactive bladder (OAB), was evaluated for in vitro skin permeation under finite conditions and in vivo transdermal absorption. Propiverine hydrochloride solubility was determined using 1,3-butyleneglycol, polyoxyethylene (2) oleylether, isostearyl alcohol, and lauryl alcohol. The solubility increased as the solubility parameter value increased. In vitro skin permeation in hairless mouse skin and in vivo transdermal absorption in rats were measured using propiverine hydrochloride dissolved in a simple solution containing these solvents. Dependent on the increase in in vitro flux, the in vivo area under the curve up to 72 h (AUC0-72) was increased. Therefore, the emulsified formulation was prepared containing these ingredients using polyoxyethylene (20) stearylether for optimization. The emulsified formulation was used to conduct in vivo single- and repeated-dose absorption studies in rats. After single-dose transdermal administration of the emulsified formulation, the AUC0-72 was equivalent to that of the simple solution. Furthermore, results using the emulsified formulation indicated an increase in AUC0-72 and significant extension of the elimination half-life, in comparison with oral administration. After repeated-dose administration, a significant minimum plasma concentration was observed compared with oral administration. These results demonstrate that the emulsified formulation is a good option for transdermal delivery of propiverine hydrochloride.