Abstract: A dual solid phase extraction (SPE) pretreatment coupling with non-gel sieving capillary electrophoresis (NGCE) analysis method was established for the quantitative determination of an antisense oligodeoxynucleotide, Cantide, in rhesus monkey plasma. The conditions of SPE and the NGCE analysis were optimized. Under the optimized conditions (the SPE conditions: the pH of loading buffer was 9.0; the volumes of loading and the elution solution for the anion-exchange column were 5 mL and 3 mL, respectively. The NGCE analysis conditions: loading gel time was 30 min and the separation voltage was 24 kV), the linear dynamic range of Cantide in rhesus monkeys plasma was 1.95-250 mg/L, and the correlation coefficient (r) was more than 0.998. The limit of quantitation was 1.95 mg/L. The intra-batch accuracies ranged from 93.38% to 100.71% with the intra-batch relative standard deviation (RSD) less than 11%. The inter-batch accuracies were from 89.46% to 103.46% with the inter-batch RSD less than 9%. The stability experiment showed that the Cantide plasma sample was stable when stored at 4 ℃ for 24 h, room temperature for 4 h, -80 ℃ for 30 days and freeze-thaw for 2 cycles. This method was finally successfully applied to pharmacokinetic study of Cantide in rhesus monkeys.

Key words: antisense oligodeoxynucleotide, Cantide, non-gel sieving capillary electrophoresis (NGCE), rhesus monkey , solid phase extraction (SPE)