The partial least square (PLS) regression method is a multivariate calibration tool that was used to determine the concentration of several analytes in a wide variety of samples, in combination with different spectroscopic techniques [1]. A PLS-UV spectrophotometric method for simultaneous determination famotidine (FAM) and domperidone (DOM) by recording absorbance data between 200-400 nm has been developed. Since adsorption spectra of these drugs are deeply overlapped, FAM and DOM cannot be directly determined by spectrophotometric methods. The chemical and instrumental variables affecting the analytical performance of methodology were studied [2,3]. For each compounds a linear calibration was obtained in the concentration range of 1.34-46.54μ gml-1 and 1.69-58.65 μgml-1 for FAM and DOM, respectively. Matrix calibration design was used in six level concentrations by using orthogonal experimental design. A cross-validation procedure was used to select the number of factors. Finally the proposed method was successfully applied to simultaneous spectrophotometric determination of FAM and DOM in a pharmaceutical formulation.
