Metabolism of Drugs. LXXVII. In Vitro Metabolism of Antipyrine

Abstract

In connection with the previous in vivo work^{3, 4)} that antipyrine was mainly metabolized to 4-hydroxyantipyrine and 3-hydroxymethyl-2-methyl-1-phenyl-3-pyrazolin-5-one (AN-CH₂OH), the in vitro metabolism of this drug was investigated by use of 9000×g supernatant fraction of rat liver. It was found that antipyrine was oxidized to 4-hydroxyantipyrine and AN-CH₂OH by the 9000×g supernatant of the liver. These metabolites were detected by means of thin-layer and gas chromatographies, and by ultraviolet absorption spectral analysis.