Purpose: To isolate and identify the main insulin aspart (AspB28 human insulin) derivatives formed in pharmaceuticals (pH 7.4 at 5 degrees C), to estimate rates of formation, and to determine their biologic potencies.
Methods: Insulin aspart derivatives have been isolated by reversed-phase high-performance liquid chromatography (RP-HPLC), and identified by RP-HPLC, peptide mapping, amino acid analysis, mass spectrometry.