Development and Validation of Spectrophotometric Methods for the Simultaneous Estimation of Miconazole Nitrate and Metronidazole in Bulk Powder Form

Simple, precise, accurate and economical spectrophotometric methods have been developed for simultaneous determination of Miconazole nitrate (MIZ) and Metronidazole (MNZ) in their bulk powder form. Method (I) is simultaneous equation method and method (II) is absorbance ratio method. This is based on measurement of absorbance at two wavelengths 318.8 nm and 279 nm, max of Metronidazole and Miconazole nitrate in pH 4.0 phosphate buffers. Both the drugs obeyed Beer-Lambert's law in the concentration range of 5-30 g/mL for Metronidazole and 100-600 g/mL for Miconazole nitrate. The high values of correlation coefficient (R 2 ) indicated good linearity of calibration curve for both the drugs. The second method i.e. absorbance ratio method which involves the formation of Q-absorbance equation using the respective absorptivity values at 283 nm (isoabsorptive point) and 279 nm (max of miconazole nitrate); accuracy, precision and recovery studies of the developed methods have been carried out in order to confirm their accuracy.