A simple and rapid method to assess butenafine hydrochloride in skin samples and a comparative cutaneous retention study of two marketed formulations.

A new method for the quantification of butenafine hydrochloride (BTF) present in the main skin layers was validated and a study conducted with the aim of analyzing the penetration and/or the permeation of the drug. The quantification was performed by liquid chromatography. To evaluate the specificity of the method, the influence of the components of the skin was analyzed, as well as the skin in contact with the excipient ingredients. Linearity was assessed with concentrations in the range of 0.1-10 μg/mL (r(2) = 0.9999) and ANOVA showed non-significant linear deviation (p > 0.05). Adequate results were obtained for repeatability, intra-day precision and accuracy. The obtained values for the limit of quantification and the limit of detection were 68.4 and 17.7 ng/mL, respectively. Also, a comparative study of BTF cutaneous penetration through porcine skin was performed applying two different formulations: Tefin, present in the Brazilian market, and Lotrimin Ultra(®) , available in the American market. No statistical difference was found in the skin (epidermis plus dermis) and in the epidermis (p > 0.05), although in the dermis the difference was significant (p < 0.05). During the experimental period (8 h), no drug permeation from either formulation was detected in the receptor fluid.