Spectrophotometric determination of benzothiadiazines in dosage forms

The analytical utility of ethyl acetoacetate for the spectrophotometric determination of benzothiadiazine diuretics has been studied. The procedure developed is based on coupling of the diazotized drugs with the reagent, which possesses an active methylene group. The stoichiometry of the reaction is presented. The nominal recovery of the drugs from pharmaceutical preparations ranges from 97.6 +/- 0.7 to 102.3 +/- 0.3%. The suggested method is simple, sensitive and applicable to unit dose analysis.