Ion-pair high-performance liquid chromatographic assay method for the assessment of clarithromycin stability in aqueous solution and in gastric juice.

A simple and selective ion-pair HPLC method has been developed for the analysis of clarithromycin in aqueous solutions and in gastric juice. A Hypersil ODS 5-microns (150 x 4.6 mm I.D.) column was used with a mobile phase consisting of acetonitrile-aqueous 0.05 M phosphate buffer (pH 4.6) containing 5 mM l-octanesulphonic acid (50:50, v/v). The column temperature was 50 degrees C and detection was by UV absorption (210 nm). The limits of detection of 50-microliters samples were 0.4 microgram/ml (aqueous) and 0.78 microgram/ml (0.5 ml gastric juice) or better. The assay was linear in the range of 1.56 to 100 micrograms/ml with r2 values greater than 0.99. The recovery from the gastric juice samples was 98.5 +/- 2.9%. The method was applied successfully to determine the stability of clarithromycin in 0.01 M HCl and gastric juice.