PERCUTANEOUS-ABSORPTION OF A NEW ANTIANDROGEN INCLUDED IN LIPOSOMES OR IN SOLUTION

The percutaneous absorption and the cutaneous distribution of a new an tiandrogen, RU 58841, 0.5% in liposomes or in solution were compared a fter topical application. In vitro percutaneous absorption experiments were performed on human dermatomed skin with Franz diffusion cells. I n vivo cutaneous distribution after application on the skin of hairles s rat was studied with the method previously described by Schaefer and Stuttgen. The in vitro experiments showed that liposomes considerably reduce the RU 58841 percutaneous absorption compared to solution. Aft er in vivo application, drug content of skin surface, stratum corneum, epidermis and dermis were measured, it demonstrated a slower permeati on of the drug and a longer duration in the epidermis and dermis for t he liposomes compared with the solution. The distribution profile of s olution presented an RU 58841 concentration gradient decreasing from t he surface to the deeper layers while an RU 58841 concentration increa se between 30 and 150 mu m in depth was observed with liposomes showin g an accumulation in the sebaceous structures. In conclusion, there is a trend towards a more favourable topical application of liposomes fo r local effects. They reduce percutaneous absorption, increase accumul ation and retention of the drug in the dermis and produce a targeting in the sebaceous structures.