Comparison of Two Pharmacopoeia Methods for Determining Higher Molecular Weight Proteins in Insulin Glargine

Objective: We compared two pharmacopoeia methods, European Pharmacopoeia (EP) and Indian Pharmacopoeia (IP),with respect to their key char­acteristics for determining higher molecular weight proteins (HMWP) in insulin glargine. These methods differ in the mobile phase composition, number of HPLC columns used and run time. Material and Methods: Testing was carried out exactly as described in the respective pharmaco­poeia methods. Results: Our results indicate that both methods provide insulin glargine peak with comparable symmetry factor. Results obtained with two methods are precise in terms of intra-assay variation; however, inter-assay variation was better with IP method. Also, both methods provide similar results in terms of estimation of HMWP content in insulin glargine. Conclusion: Based on the findings we propose that IP method may replace EP method for determination of HMWP content in insulin glargine which will reduce the analysis time and running cost of the test without compromising with the results. Key words: HMWP, Insulin glargine, Monomer, Pharmacopoeia, Size exclusion HPLC.