Abstract: AIM: To study the relative bioavailability and bioequivalence of cyclovirobuxine D orally disintegrating tablets and cyclovirobuxine D tablets in healthy volunteers. METHODS: 2 mg of cyclovirobuxine D orally disintegrating tablets and cyclovirobuxine D tablets was given to 22 healthy volunteers in a randomized crossover study. The concentration of cyclovirobuxine D in plasma was determined by LC/MS/MS after a solid phase extraction (SPE).The pharmacokinetic parameters were calculated and the bioavailability and bioequivalence of two formulations were evaluated by DAS 2.0 software. RESULTS: After a single dose, the pharmacokinetic parameters of cyclovirobuxine D and reference were as follows:C_max, (121±55) and (122±52) ng/L;t_max, (10±7) and (12±8) h;AUC_0-120 h, (4398±1656) and (4524±1760) ng·L^-1·h;AUC_0→inf, (5292±2034) and (5440±2446) ng·L^-1·h, respectively.The 90% confidential interval of C_maxof cyclovirobuxine D orally disintegrating tablet was 82.7%-117.3%.The 90% confidential interval of AUC_0-120 and AUC_0→inf of cyclovirobuxine D orally disintegrating tablet were 83.9%-112.9% and 83.4%-117.6%, respectively. CONCLUSION: The relative bioavailability of cyclovirbuxine D orally disintegrating tablets to cyclovirobuxine D tablets is (97.7±14.7)%.The results of the statistic analysis show that the test and reference formulations are bioequivalent.

Key words: buxine, cyclovirobuxine D, pharmacokinetics, bioequivalence, solid phase extraction, LC/MS/MS