Quantitative analysis of povidone (PVP) in drug-PVP matrix using multicomponent analysis

A method for the quantification of povidone (PVP), in solid dispersions and physical mixtures of the polymer and a very slightly soluble drug substance, has been developed by multicomponent analysis using the concepts of chemometrics. Because the UV-absorbance spectra of PVP is completely overlapped by the UV-absorbance spectra of the drug substance, a direct spectrophotometric method of PVP is impossible. However, UV-spectrophotometric data were analyzed by the Quant + Perkin Elmer software for quantitative multicomponent analysis using chemometrics, and by the optimal method developed using a solvent of pH 7.4, a fast, reliable, and precise detection of PVP was obtained when the content of PVP in the powder sample exceeded 20% (m/m). Two methods were developed by the calibration procedure, using buffers of pH 7.4, respectively pH 8.5. By applying a solvent of pH 8.5, more sample could be taken into use because of the enhanced solubility of the drug substance, and hence it was believed that as more PVP was taken into use, a better prediction of PVP would be obtained. However, as more drug substance was taken into use the UV-absorbance spectrum of PVP was even more overlapped, and an inferior prediction was obtained.