08. February 2016

Protamines are a group of highly basic peptides which is sometimes added to insulin formulations to prolong the pharmacological action. In this study, different methods were investigated in order to identify protamine in insulin formulations. Capillary electrophoresis in aqueous and non-aqueous media was tested to separate these peptides with very close amino acid sequences. Different buffers (phosphate or formate, both acidified) and various additives (principally negatively charged and...