A new insulin immunoassay specific for the rapid-acting insulin analog, insulin aspart, suitable for bioavailability, bioequivalence, and pharmacokinetic studies

Objectives: To validate a specific enzyme-linked immunosorbent assay for th e rapid-acting human insulin analogue, insulin aspart, in human serum, huma n plasma, and porcine plasma. Design and methods: For the enzyme-linked immunosorbent assay, two murine m onoclonal antibodies were developed that bind to two different epitopes on the insulin aspart molecule. Key parameters for validation were imprecision , accuracy, matrix effects, dilution-linearity, and cross-reactivity. Results: No cross-reactivity was found with human and porcine insulin, huma n proinsulin, or human C-peptide. The assay is sensitive (limit of quantifi cation = 11.5 pmol/L), accurate (95-107% recovery with human serum, human p lasma, and porcine plasma in the range 16-800 pmol/L), and has a 14.7% tota l imprecision within the entire analytical range. Dilution of samples gave linear results with human serum as the diluent. Conclusions: The insulin aspart-specific enzyme-linked immunosorbent assay described in this study is well suited to study the bioavailability, bioequ ivalence, and pharmacokinetics of this insulin analogue. Copyright (C) 2001 The Canadian Society of Clinical Chemists.