A new potential antiinflammatory substance serves as an example that substantiates the necessity of carrying out concurrent comparative pharmacokinetic and biotransformation studies of new drugs in experimental animals and man during the preclinical research stage, with adherence to all safety precautions. Such a procedure will facilitate the choice of an animal model that approaches human metabolism and pharmacokinetics as closely as possible. This serves in the further development of the test drug, and thus enhances the validity of the transfer of experimental data to man, especially from the toxicological aspect.