RAPID REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY-METHOD FOR RANITIDINE HYDROCHLORIDE IN DOSAGE FORMS

A HPLC method with photometric detection has been developed for the ra pid assay of ranitidine hydrochloride in dosage forms and samples from tablet dissolution testing. This method also separates ranitidine fro m its related compound ranitidine S-oxide. Analyses were carried out o n a Microsorb-MV C18 column, with a (1:1) mixture of methanol-0.01 M N a2HPO4 (pH 7.0) as the mobile phase, and detection at 320 nm. At a flo w rate of 1.0 mL/min, typical retention times for ranitidine and its S -oxide compound were 3.50 min and 1.95 min, respectively. Detector res ponses were linearly related to on column concentrations of ranitidine and ranitidine S-oxide in the ranges 0.035-9.000 mu g and 0.005-0.320 mu g, respectively. Recoveries of ranitidine from spiked synthetic fo rmulations simulating tablets, injections and syrups ranged from 99.7 +/- 0.5% to 100.5 +/- 0.5% of the added amount (n = 2). For assay purp oses, tablets were extracted into or liquid samples (injections, syrup s) were quantitatively diluted with methanol-water (1:1), and the solu tions were injected onto the column. Samples from tablet dissolution t ests required no preliminary preparation. Assay values by the proposed method were found to agree closely with those obtained using methods in the USP XXII.