RESUMO
Two simple, accurate, and reproducible spectrophotometric methods for the determination of Xipamide [XIP] in pure form and in pharmaceutical preparations were described. The first method was based on the formation of orange complex between iron [III] chloride and the investigated drug. The method permits the determination of XIP over a concentration range 20-160 micro g ml[-1] at 490 nm. The second method was developed by formation of ternary complex by reaction of the drug with Fe [III] chloride and ophenanthroline [phen] in the presence of sodium lauryl sulphate as surfactant and measuring the absorbance at 440 nm. The method obeys Beer's law over the concentration range of 10-80 micro g ml[-1]. The factors affecting the formation of complexes were studied and optimized. The relative standard deviations of these methods were less than 1.0% and their detection limits were 2.75-4.45 micro g ml[-1]. The methods have been successfully applied for the determination of the studied drug in its pharmaceutical tablets and the results obtained were in good agreement with those obtained by the reference method