Sensitive and accurate method for chromatographic quantification of ibandronate in bulk and dosage forms

Purpose: To develop a simple, accurate and reproducible chromatographic method for determination of ibandronate. Methods: Lack of chromophore groups in their structure is a problem with the determination of bisphosphonates. The developed method relies on chromatographic determination following derivatization of ibandronate with NBD-Cl. Separation and quantification of reaction products were done using HPLC system (LA CHROM MERCK HITACHI) composed of an isocratic pump (model L–7110) supplied with UV-visible wavelength detector (Model 7120) with Rheodyne injector (model 7161) and equipped with a 20-µL injector loop. Results: Ibandronate was successfully derivatized with NBD-Cl to enhance its HPLC separation and quantification. The reaction conditions were optimized to achieve maximum sensitivity of the assay. The studied drug was satisfactorily quantified in the concentration range of 500 - 5000 ng/mL. Method validation was successfully performed in line with ICH directives in terms of robustness, accuracy, linearity and precision of the test method. The proposed method was satisfactory for the determination of ibandronate in either bulk and dosage forms. Conclusion: An accurate and reproducible method for regular quantification of ibandronate has been developed, and it is suitable for use in analytical laboratories, including those of regulatory agencies.