Dual Wavelength Spectrophotometric Method for the Simultaneous Estimation of Rifampicin and Piperine in Their Combined Capsule Dosage Form

The present manuscript describe simple, sensitive, rapid, accurate, precise and cost effective dual wavelength spectrophotometric method for the simultaneous determination of Rifampicin and Piperine in combined capsule dosage form. The utility of dual wavelength data processing program is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The principle for dual wavelength method is “the absorbance difference between two points on the mixture spectra is directly proportional to the concentration of the component of interest”. The method was based on determination of Rifampicin at the absorbance difference between 286 nm and 357 nm and Piperine at the absorbance difference between 356 nm and 479 nm. The linearity was obtained in the concentration range of 10-60 μg/ml for Rifampicin and 1-10 μg/ml for Piperine. The mean recovery was 98.40 ± 0.48 and 98.59 ± 0.46 for Rifampicin and Piperine, respectively. The method was successfully applied to pharmaceutical dosage form because no interference from the capsule excipients was found. The suitability of these methods for the quantitative determination of Rifampicin and Piperine was proved by validation. The proposed methods were found to be simple and sensitive for the routine quality control application of Rifampicin and Piperine in pharmaceutical capsule dosage form. The results of analysis have been validated statistically and by recovery studies.