TESTOSTERONE β-CYCLOPENTYLPROPIONATE: A NEW LONG-ACTING ANDROGEN

Abstract

Considerable attention has been given to the attainment of ideal androgen response by utilizing repository forms of micro-crystalline testosterone as well as the ester, testosterone propionate. Some 15 new testosterone esters were screened for intensity and duration of androgen effect in the immature intact rat. Seminal vesicle and prostrate growth response were noted. From these studies testosterone beta-cyclopentylpropionate (TCP) was selected. Further study of this new androgen in comparison with testosterone propionate and aqueous suspension of free testosterone in castrate rats has disclosed that it produces greater and more prolonged effects. The seminal vesicle growth responses on the 18th to 30th days after admn. are about 10 times those obtained with testosterone propionate. Acute and chronic toxicity studies showed that the cyclopentylpropionate was no more toxic than the propionate and, therefore, safe for human studies. Clinical work demonstrated the desired properties of this new androgen.