Abstract: AIM: To establish a simple, rapid and accurate high performance liquid chromatographic method (HPLC) for the determination of cyclosporin A (CsA) in human whole blood, and to study the influence of nicotinylmethylamide (Nic) on the pharmacokinetic parameters of cyclosporin A (CsA). METHODS: Whole blood CsA concentrations were measured by HPLC in 18 healthy volunteers administrated single CsA or co-administrated Nic.The data of time-blood concentrations of CsA were analyzed by 3p97 Program.The analysis of variance and two one-sided t-test were used to compare the main pharmacokinetic parameters of CsA in the two administrations. RESULTS: C_max and AUC_0~∞of CsA had statistically significance between the single CsA group and coadministration of Nic group (P <0.01), while t _1/2(β) and T_max of CsA had no statistically significance between the two groups (P >0.05). CONCLUSION: This HPLC method is simple, sensitive and accurate, and is suitable for routine determination of blood CsA levels in human. Nic can improve the absorption of CsA and increase the C_max and AUC of CsA, but has no influence on the metabolism of CsA.

Key words: cyclosporin A, nicotinylmethylamide, HPLC, pharmacokinetics