Some metabolic aspects of a nitrogen mustard of prednisolone.

Prednimustine (Leo 1031), a conjugate of prednisolone and chlorambucil, was administered to humans and baboons and the metabolic fate of the compound ascertained. Compared to the excretion of prednisolone, prednimustine is excreted more slowly and less quantitatively, with a significant part of the compound being retained in the body. Hydrolysis of the prednimustine molecule appears to take place quantitatively after oral administration, but a substantial part of prednimustine appears to remain intact after its intravenous administration. Fecal excretion of radioactivity was minor compared to the urinary route. The biliary excretion in the baboon was relatively insignificant. Localisation within the lung and spleen of the baboon points to a potential therapeutic use of this drug in neoplastic conditions affecting these organs.