Brain-enhanced delivery of testosterone using a chemical delivery system complexed with...

Enhanced brain delivery of testosterone was suggested by application of a dihydropyridine in equilibrium pyridinium salt redox system. The drug delivery method is based upon the NAD+ in equilibrium NADH coenzyme system and utilizes the covalent attachment of testosterone to a dihydropyridine-type carrier. Upon administration of two such testosterone chemical delivery systems (T-CDS1 or T-CDS2), serum LH levels were suppressed by 71-87% after 24 hours and maintained through 5 days (28%) with T-CDS1. An equimolar dose of testosterone or testosterone propionate failed to suppress serum LH. Peripheral testosterone target tissues (seminal vesicles and prostate gland) were only slightly stimulated by T-CDS1. Complexation of T-CDS1 with 2-hydroxypropyl-beta-cyclodextrin allowed a lowering of the effective LH-suppressing dose of T-CDS1 from 25 mg/kg to 10 mg/kg, presumably by increasing the solubility of T-CDS1 in the blood. These findings suggest that testosterone can be effectively delivered to the central nervous system (CNS) with minimal peripheral effect, and the delivery of T-CDS1 to the CNS can be improved via complexation with 2-hydroxypropyl-beta-cyclodextrin.