Comparative Evaluation of Testosterone Release and its Derivatives in Adult Male Monkeys

The present study was undertaken to compare the release of testosterone and its derivatives in adult male bonnet monkeys by different routes. Testosterone and its derivatives such as T.propionate, T.enanthate, T.undecanoate, T.busiclate and 7 -Methyl 19-nortestosterone (MENT) were administered via different routes that includes intramuscular, Alzet pump and Silastic tubing. It was observed that 5 ng/ml testosterone concentration was maintained up to 45 days with esters like enanthate, undecanoate or buciclate when given via Alzet pump, whereas with Silastic implants, the testosterone concentration was maintained at 5 ng/ml up to 105 days in the enanthate group, 112 days in the undecanoate group and 133 days in the buciclate group. The results of the study clearly establish the efficacy of delivery by Silastic tubing, which maintained high concentration of testosterone buciclate even on Day 49 compared to 18 days by Alzet pumps or only for 13 days by intramuscular route.