Validity and use of a non-parallel insulin assay for pharmacokinetic studies of the rapid-acting insulin analogue, insulin aspart.
A radioimmunoassay (RIA) for insulin was validated for reliable measurement of the human insulin analogue, insulin aspart, by correction of non-linear measurements. Specificity was equivalent for several species of insulin, except insulin aspart. A non-linear hyperbolic model fitted insulin aspart with a correction formula for non-linearity of: z = 1,503y/ (1,398 - y), where y denotes measured concentration and z denotes true concentration. Matrix-effects were insignificant for human, porcine, and canine heparin-plasma and for human and porcine serum. The coefficient of variation was below 15% for 80-800 pmol/L human and porcine insulin and for 80-600 pmol/L insulin aspart. The limit of detection for insulin aspart was 11.5 pmol/L with a lower limit of quantification of 17.5 pmol/ L. Dilution of serum with Pharmacia dilution media introduced no significant error. In conclusion, this paper demonstrates that a non-parallel radioimmunoassay can be used to estimate accurate concentrations of insulin aspart.
Andersen
L
L
Novo Nordisk A/S, Novo Allé, Bagsvaerd, Denmark.
Vølund
A
A
Olsen
K J
KJ
Plum
A
A
Walsh
D
D
D000818:Animals; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D061267:Insulin Aspart; D011863:Radioimmunoassay; D012680:Sensitivity and Specificity; D013552:Swine
D007328:Insulin; D061267:Insulin Aspart