Analysis of azithromycin and its related compounds by RP-HPLC with UV detection

A simple, validated stability-indicating liquid chromatographic method is developed for the analysis of azithromycin in raw material and in pharmaceutical forms. Liquid chromatography with a UV detector at a wavelength of 210 nm using a reversed-phase C(18) stationary phase has been employed in this study. Isocratic elution is employed using a mixture of phosphate buffer-methanol (20:80). This new method is validated in accordance with USP requirements for new methods for assay determination, which include accuracy, precision, specificity, linearity, and range. This method shows enough selectivity, sensitivity, accuracy, precision, and linearity range to satisfy Federal Drug Administration and International Conference of Harmonization regulatory requirements. The current method demonstrates good linearity over the range of 0.3-2.0 mg/mL of azithromycin. The accuracy of the method is 100.5% with a relative standard deviation of 0.2%. The precision of this method reflected by relative standard deviation of replicates is 0.2%. The method is sensitive with a detection limit of 0.0005 mg/mL for azithromycin. Impurities and degradation products of azithromycin can be selectively determined with a good resolution in both raw material and pharmaceutical forms.