Simultaneous high-performance liquid chromatographic analysis for famotidine, ranitidine HCl, cimetidine, and nizatidine in commercial products

A high-performance liquid chromatographic (HPLC) procedure for the simultan eous determination of famotidine (FMT), ranitidine HCl (RNT), cimetidine (C MT), and nizatidine (NZT) was developed using a two-level, full-factorial d esign with three variables (volume of methanol, percentage of triethylamine , and concentration of phosphate buffer) to select an acceptable mobile pha se. A column (15 cm x 4.6 mm ID) of Inertsil ODS-2 (5 mu m) was used, and 0 .04M aqueous sodium dihydrogen phosphate/acetonitrile/methanol/TEA at a pro portion of 345/20/35/0.7 (v/v/v/v) was the selected mobile phase (I ml/min) . The detection wavelength was set at 230 nm and procaine HCl was used as t he internal standard. Precision and linearity of the method were assessed. None of the commercial samples was found to be outside the compendial limit s of 90.0% to 110.0% of the claim amount.