QUANTITATIVE DETERMINATION OF DANTROLENE SODIUM AND ITS METABOLITES BY DIFFERENTIAL PULSE POLAROGRAPHY

A differential pulse polarographic method has been developed for the simultaneous determination of dantrolene sodium and its nonreduced and reduced metabolites. The compound and its metabolites are extracted from urine or plasma with ethyl acetate and the ethyl acetate removed by evaporation. The compounds are dissolved in a small quantity of N,N‐dimethylformamide and diluted with 0.2 M pH 4 acetate buffer. Dantrolene sodium plus the reduced and nonreduced metabolites are quantitatively determined by the polarographic reduction of the azomethine linkage at a cell potential of −0.86 v. The nitro compounds are quantitatively determined as dantrolene equivalents by the reduction of the nitro group at a cell potential of −0.26 v. The difference between the two determinations represents the reduced metabolites. Levels as low as 0.1 mcg./ml. can be determined by the reduction of the nitro group or the azomethine linkage. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company