Metabolism of testosterone 4-14C in skin of castrated rats

In vivo absorption of steroidal hormones from smart polymer based delivery systems

The purpose of this study was to develop smart polymer based controlled delivery systems to deliver steroidal hormones after single subcutaneous (s.c.) injection at predetermined rates over extended period of time. In vivo absorption and pharmacokinetics of levonorgestrel (LNG) and testosterone (TSN) were investigated from the thermosensitive and phase sensitive polymeric controlled delivery systems. A selective, reliable, and rapid method for determination of serum LNG concentration was developed using high-performance liquid chromatography-tandom mass spectrometry with atmospheric pressure chemical ionization interface (HPLC-MS-MS with APCI), while TSN in serum samples was detected and quantified by a competitive immunoassay. The delivery systems controlled the absorption of LNG in rabbits up to 6 weeks from thermosensitive and approximately 4 weeks from phase sensitive polymeric delivery systems. In vivo study of TSN delivery systems in castrated rabbits controlled the release of TSN for at least 2 months from both thermosensitive and phase sensitive polymers. Thermosensitive and phase sensitive polymer formulations significantly (p < 0.05) increased relative bioavailability of steroidal hormones compared to control. In conclusion, thermosensitive and phase sensitive polymer based delivery systems controlled the release in vivo in rabbits for longer duration after single s.c. injection.

Uptake of 3H-testosterone in the skin of healthy women and in the skin of patients with acne vulgaris

Skin samples of interscapular region were taken from healthy women and patients with Acne vulgaris. The material was incubated with 3H-testosterone. The incubation of a part of the material was preceeded by an incubation with the unlabelled testosterone. An autoradiography was employed to detect and localize an uptake of 3H-testosterone in the skin. A significantly greater 3H-testosterone uptake was noted in the stratum basale and stratum spinosum of epidermis, sebaceous glands and hair sheaths and, in patients with Acne vulgaris, also within hair sacs and comedons.