Abstract

A fluorimetric procedure, involving simple extraction techniques, has been described for the determination of 0.005 µg or more of a major metabolite appearing in plasma after oral administration of spironolactone. Data obtained by fluorescence characteristics and paper chromatography indicate that the metabolite is the de-thioacetylated derivative, 3-(3-oxo-17β-hydroxy-4,6-androstadien-17α-yl) propionic acid γ-lactone. Plasma levels of this metabolite versus time curves are shown for human subjects after oral administration of spironolactone.