Developing and Validating a Robust RP-HPLC Method for Metoclopramide and Camylofin Simultaneous Analysis Using Response Surface Methodology.

In this study, the establishment and validation of a stable reversed-phase high-performance liquid chromatography (RP-HPLC) method for the concomitant estimation of the two drugs in dosage forms are presented. Method optimization was achieved by response surface methodology (RSM) using Design Expert Software 13, taking into account the special physicochemical characteristics of metoclopramide (MET) (a moderately polar molecule, pKa 9.5) and camylofin (CAM) (a less polar, hydrophobic molecule, pKa 8.7). Chromatographic resolution was achieved on a phenyl-hexyl column under isocratic mobile phase mode in which methanol and 20 mM ammonium acetate buffer (pH 3.5) were used to provide maximum analyte interaction and resolution. The method was found to have good linearity for both analytes (R 2 > 0.999) over the concentration ranges studied. Limits of detection were 0.23 and 0.15 μg/mL for MET and CAM, respectively, and corresponding limits of quantification were 0.35 and 0.42 μg/mL, respectively. Recovery tests gave high precision values of 98.2%-101.5%, while intra- and inter-day precision in relative standard deviation (RSD) was below 2%. The method was effectively applied for the analysis of commercial tablet formulations, confirming its reliability and suitability for routine quality control and regulatory analyses. Overall, the validated RP-HPLC method provides a sensitive, accurate, and efficient means of simultaneous determination of MET and CAM in pharmaceutical dosage forms.