Chemometric assisted spectrophotometric methods for the simultaneous determination of Rifampicin and Piperine in bulk and capsule

In this work a numerical method, based on the use of spectrophotometric data coupled to Partial least squares (PLS),Principal component regression (PCR) andclassical least square (CLS) multivariate calibration, is evaluated for the simultaneous determination of rifampicin and piperine in bulk and capsule dosage form. Spectra of RIFA and PIPE were recorded at concentrations within their linear ranges 20-50 μg/ml & 1.0 - 2.5 μg/ml, respectively and were used to compute a total of 25 synthetic mixtures involving 16 calibration and 9 validation sets between wavelength range of 200 and 500 nm with the wavelengths intervals λ=5 nm in methanol. The suitability of the models was decided on the basis of root mean square error (RMSE) values of calibration and validation data. The analytical performances of these chemometric methods were characterized by relative prediction errors and recovery studies (%) and were compared with each other. These three methods were successfully applied to pharmaceutical formulation (capsule) with no interference with excipients as indicated by the recovery study results. The proposed methods are simple, rapid and can be easily used as an alternative analysis tool in the quality control of drugs and formulation.