Separation and identification of urinary metabolites of ${}^{14}\text{C}\text{-p-n-}\text{butoxyphenylacethydroxamic}$ acid in man

Abstract

The metabolic fate of ${}^{14}\text{C}\text{-p-n-}\text{butoxyphenylacethydroxamic}$ acid (Droxaryl) is studied in Man after oral and rectal administration of the drug. The fractionation of the urinary metabolites was undertaken by ion-exchange chromatography on DEAE-Sephadex A-25 columns (0·01 M Tris-Cl buffer, pH 7·2, elution with a linear gradient of NaCl). The identification of the degradation compounds shows that the main metabolic routes seem to be the conjugation with glucuronic acid (about 70%) and with sulfuric acid (about 5–10%). Hybrid compounds cannot be excluded. Important degradation reactions occur also in the functional group of Droxaryl. The main differenne in the metabolic behaviour of Droxaryl after oral or rectal administration in Man is the higher amount of unchanged drug in the urine of rectally treated patients.