SYNTHESIS OF C-14 AND TRITIUM LABELED METHYLPREDNISOLONE SULEPTANATE

Methylprednisolone suleptanate was initially labeled with tritium in the A‐ring of the steroid portion of the molecule, and with carbon‐14 at both carboxylic carbons of the suberic acid portion of the side chain. However these labels proved to lack total metabolic stability after administration to rats. Subsequently a second pair of labeled methylprednisolone suleptanates was synthesized, with tritium at C‐7 in the B‐ring of the steroid and carbon‐14 exclusively at the carboxamide carbon in the side chain. These labeled compounds showed excellent metabolic stability of both the tritium and carbon‐14 labels, and should be well suited for conducting drug disposition studies. Copyright © 1990 John Wiley & Sons, Ltd.