Spectrophotometric determination of meloxicam by sodium nitroprusside and 1,10-phenanthroline reagents in bulk and its pharmaceutical formulation

Two simple and selective spectrophotometric methods have been developed for the quantitative determination of meloxicam in pure form and in pharmaceutical formulations. The first method is based on the electron transfer reaction of drug with sodium nitroprusside in presence of hydroxyl amine HCl and the absorption maxima is recorded at 363 nm (Method A). Second method is based on the formation of a complex of drug with ferric chloride and followed by coupling with 1,10-phenanthroline, and the absorption maximum is recorded at 343 nm (Method B). Both the methods follow Beer's range in the concentration range 4-20 mu g mL(-1) and 10-50 mu g mL(-1) for Methods A and B respectively. Good correlation coefficients (0.9955-0.9973) are observed between absorbance and corresponding concentrations of the drug. The calculated apparent molar absorptivity values are found to be 0.6079 x 10(-4) and 0.4849 x 10(-4) mol(-1) cm(-1) for the Methods A and B respectively. The limits of detection and quantification are also reported for both spectrophotometric methods. Intra-day & inter-day precisions and the accuracy of the methods have also been evaluated. No interference is observed from common pharmaceutical adjutants. The reliability of the methods is further ascertained by performing recovery tests by standard addition method.