LIQUID-CHROMATOGRAPHY OF JOSAMYCIN ON POLY(STYRENE-DIVINYLBENZENE)

An isocratic liquid chromatographic method for the assay and purity co ntrol of josamycin using wide-pore poly(styrene-divinylbenzene) as the stationary phase is presented. Josamycin has been well separated from all the related leucomycins, present as impurities in commercial samp les. Wide-pore PLRP-S 8 mu m 1000 A has shown the best selectivity. Th e separation has been carried out at 65 degrees C with a mobile phase of 2-methyl-2-propanol/0.2 mol/l potassium phosphate buffer pH 10.5/wa ter (24.5: 5: 70.5, V/V) and a flow rate of 1.0 ml/min. UV detection h as been performed at 232 nm. The total analysis time has been about 40 min. The method has been used to analyse commercial bulk samples and tablets containing josamycin base.