Determination of ibandronate and its degradation products by ion-pair RP LC with evaporative light-scattering detection

A simple method has been developed for analysis of ibandronate and related substances by ion-pair reversed-phase high-performance liquid chromatography (RPIC) with evaporative light-scattering detection (ELSD). After optimization of the chromatographic conditions satisfactory separation of the compounds was achieved on an Intersil C-8 column with an isocratic mobile phase-8:4:88 (v/v) acetonitrile-methanol-12 mM ammonium acetate buffer containing 35 mM n-amylamine (pH 7.0). The mobile phase flow rate was 1.0 mL min(-1). The calibration plot was linear in the range 352 to 1760 mu g mL(-1) for ibandronate. The precision and reproducibility were 0.3% and 0.5%, respectively. The average recovery of ibandronate was 100.4% and RSD was 0.6%. The method was validated and shown to be precise, accurate, and specific far assay of ibandronate in bulk material and dosage forms. The proposed liquid chromatographic method can be satisfactorily used for quality control of ibandronate.