gamma-Cyclodextrin:testosterone complex suitable for sublingual administration

A crystalline complex of testosterone with gamma-cyclodextrin was evaluated for solubility and dissolution rate. Whereas these parameters were at least an order of magnitude lower than those of testosterone complexes with amorphous derivatives of cyclodextrins, the properties of the crystalline complex enabled the preparation of a suitable pharmaceutical form for the sublingual administration of hormone to humans. This is in contrast to the situation with similar beta-cyclodextrin complexes, in which such administration was ineffective. Sublingual administration of the gamma-cyclodextrin complex, as shown in previous work using amorphous complexes, avoided rapid first-pass loss of hormone and directed it effectively into the circulation; administration of the complex into the stomach resulted in much lower circulatory hormone levels.