Evaluation of percutaneous absorption performance for human female sexual steroids into pentravan cream

There is a lack of studies on Pentravan cream, a widespread transdermal vehicle which is used by compounding pharmacies. The purpose of this study was to evaluate this transdermal vehicle. The permeation performance for progesterone, estradiol, and estriol in formulations containing each of those drugs separately, as well as an association of estradiol + estriol (Biest), was evaluated regarding their compounding process and their potential biological application. An excised female human skin model was used to predict the permeation and the retention of the active compounds in every skin layer in lieu of conventional tape stripping. Progesterone was the drug with the highest permeation (37.02 mcg cm(-2) at the end of the experiment). Estradiol and estriol in Biest had permeations approximately 4-fold lower (9.44 mcg cm(-2) for estradiol-Biest and 14.02 mcg cm(-2) for estriol-Biest), and the profiles of estradiol in Eemuls and in Biest were almost the same (9.46 mcg cm(-2) for Eemuls). All permeations followed pseudo- first order kinetics. For progesterone, using the percentage of permeation by dose, one can infer that a patient using the 1-g emulsion dose released by the pump containing 50 mg of progesterone will have 38.4 mg of progesterone liberated into his bloodstream, gradually and continuously for 48 hours. The results indicate that the vehicle was able to provide percutaneous absorption rates compatible with and higher than clinical treatment needs. Using the same rationale, the Eemuls would deliver practically the entire amount of estradiol load per dose (1.0 mg), approximately 0.5 mg of estradiol per day. As for the Biest, the dosing used would deliver almost 0.5 mg estradiol/day and 2.0 mg estriol/ day. Thus, according to the results, human female sexual hormones incorporated in the oil-in-water vanishing cream base and applied topically are expected to exert their biological activities systemically with good efficacy due to their satisfactory permeation through human skin. However, one must take into account that a high quantity of drug was delivered. Thus, to avoid patient overdose, care has to be taken regarding the quantity of emulsion used.