Rapid and Sensitive Hplc Determination of Ranitidine in Plasma. Application to Pharmacokinetics Study

Abstract

A rapid and sensitive reversed-phase high-performance liquid chrormatography (RP-HPLC) method for the separation and quantification of the H₂-receptor antagonist drug ranitidine in human plasma is described. The extraction of ranitidine from plasma by an organic solvent was eliminated in this method. Instead, the pre-chromatography isolation of the drug was done by adding approximately 50 mg of zinc sulfate and 200 μL of acetonitrile in 1.0 mL of plasma. A short column packed with pH-stable (1–13) reversed phase PLRP-S^TM particles was used with an isocratic elution of 5.0mM dibasic potassium phosphate plus 0.50mM tetraethyl ammonium hydroxide/ acetonitrile, 80:20 (v/v). The ranitidine was monitored at 315 nm and 0.20 to 0.002 absorption units full scale (AUFS). The completion time of the assay was less than 15 minutes and had a limit of detection of 1.0 ng/mL for a 100-μL injection volume. After an oral dose of 150 mg of ranitidine, plasma samples were collected at several time points and were analyzed by using this method to determine various pharmacokinetic parameters.