Validation of the ADVIA Centaur® XP system for the determination of insulin and its application

In this study, a direct chemiluminescent immunoassay for the determination of human serum insulin levels using the ADVIA Centaur® XP system was validated. Dilution recovery, linearity, precision, sensitivity, between analyzer variation, reference interval and stability were analyzed. The linear range of the insulin assay was from 0.64 to 277.27 mU/L. Intra- and inter-assay coefficients of variation were 3.67-7.96% and 4.66-8.69%, respectively. The lower and upper limits of quantification were 0.61 mU/L and 8872.64 mU/L, respectively. In terms of between analyzer variation, our study showed comparable results with a good correlation of r² = 0.9934. The human serum insulin reference interval was in the range of 3.0-25.0 mU/L. Serum insulin can be kept for 7 days between 2-8 °C and 18-26 °C, and the corresponding results for -20 °C and -70 °C were 1 month and 6 months are reported. We proved that this insulin assay was robust and the analytical performance met the requirements. We successfully applied this insulin assay to a bioequivalence study of miglitol in 48 healthy Chinese subjects. The miglitol bioequivalence study was evaluated based on pharmacokinetic and pharmacodynamic parameter endpoints. The results demonstrated that the test formulation and the reference formulation were bioequivalent.