Spectrophotometric and spectrofluorimetric determination of certain diuretics in pure forms and in their pharmaceutical formulations

ABSTRACT

Three Simple and selective spectrophotometric and spectrofluorimetric methods were developed for the quantitative determination of certain diuretics [bendroflumethiazide, benzthiazide, chlorthalidone, clopamide, hydrochlorothiazide, hydroflumethiazide, indapamide and xipamide] in pure forms as well as in their pharmaceutical formulations through their hydroxamate formation and subsequent complexation with iron [method I], reaction with potassium ferricyanide [method II] and reaction with 4-chloro-7-nitrobenzofurazan [method III]. The conditions for different reactions were studied and optimized. The methods have been validated and successfully applied to the analysis of bulk drugs and their tablets with good recoveries ranging from 97.93 [ +/- 1.46] to 100.6 [ +/- 1.75] for method I. 98.49 [ +/- 1.43] to 99.86 [ +/- 0.87] for method II, and 98.98 [ +/- 1.11] to 99.90 [ +/- 0.86] for method III. No interference was observed from common pharmaceutical adjuvants. The results obtained compare well with those of reported methods: