Comparision of two HPLC methods for determination of higher molecular weight protein in insulin glargine

The current British Pharmacopoeia requirements, quality testing of Insulin glargine involves identification, related proteins, HMWP and assay by HPLC methods. RP-HPLC is used for tests on identification, related proteins and assay while SE-HPLC is the method of choice for determination of HMWP. Current BP 2015 method on determination of HMWP of the Insulin glargine employs two HPLC columns in series with run time of about 65 minutes. However, IP 2014 describes the HMWP test on Human insulin using single HPLC column with run time of about 35 minutes. As the molecular weights and amino acid sequence of Insulin glargine and Human insulin are very close, we may expect that the two molecules should have similar chromatographic profile when tested for their HMWP content. Therefore, it would be interesting to investigate the results of test on HMWP of Insulin glargine by the methods described in two pharmacopoeias i.e. BP 2015 and IP 2014.