Permeation of cyproterone acetate through pig skin from different vehicles with phospholipids.

The permeation of cyproterone acetate (CPA) from Derma Membrane Structure (DMS) creams and liposomal formulations was investigated. Standard diffusion experiments with dermatomed porcine skin were performed. The cumulative CPA amount permeated of the DMS creams was between 2.9 and 6.8 microg/cm(2) within 48 h. By addition of a phospholipid concentrate, the CPA permeation could be 2.6-fold further increased compared to the control DMS. A working temperature of 60 degrees C resulted in a change of the preparation and a higher permeation which could be confirmed by additional differential scanning calorimetry studies. In case of the liposomal formulations, the CPA permeation was strongly dependent on the lipid content. The higher the lipid content, the higher was the CPA permeation. Extruding procedures for decreasing the particle size of the liposomes resulted in a two-fold increase in CPA permeation compared to the unextruded liposomes. It is possible to control the CPA permeation by combining various formulations containing different phospholipids with saturated and unsaturated fatty acids.