Bodor N, Sloan K B
J Pharm Sci. 1982 May;71(5):514-20. doi: 10.1002/jps.2600710509.
Progesterone and testosterone are natural soft drugs, but to be used as drugs, their fast and facile metabolism must be prevented and their delivery controlled. A prodrug-soft drug combination can serve this purpose. Thiazolidines of testosterone, testosterone 17-propionate and progesterone were synthesized from the reaction of cysteine alkyl esters, N-methylaminoethanethiol, and mercaptamine and their hydrochlorides with the appropriate steroids. The thiazolidines function as bioreversible derivatives of the parent steroids.