Bioequivalence of metformin enteric-coated pellet capsules in Chinese healthy volunteers

OBJECTIVE To study the relative bioavailability and bioequivalence of metformin enteric-coated pellet coated capsules in Chinese healthy volunteers.METHODS A single oral dose (250 mg of tested and reference formulation) was given to 20 healthy volunteers in a randomized crossover study,with one week dose interval.The plasma metformin concentrations was determined within 16 h administration by HPLC.The pharmacokinetic parameters were calculated and the bioavailability and bioequivalence of two formulations were evaluated by DAS program.AUC(0-24) and Cmax was analyzed by ANOVA followed by test,tmax was analysed by rank sum test.RESULTS After a single dose administration,the pharmacokinetic parameters for metformin enteric-coated pellet capsules were as follows:Cmax was (46.3±21.1) μg·L-1 and (44.6±17.4) μg·L-1,tmax was (1.13±0.5) h and (1.19±0.34) h; AUC(0-24) was (164.4±83.3) μg·L-1·h and (156.1±69.7) μg·L-1·h; AUC0-∞ was (173.8±87.4) μg·L-1·h and (161.0±69.7) μg·L-1·h for T and R respectively.The 90% confidential interval of Cmax,AUC(0-24) of tested formulation was 89.9%-112.1% and 95.8%-109.8%,respectively.CONCLUSION The relative bioavailability of the tested for mulations compared with the reference formulations was (104.1±18.5) %.The statistic analysis shows that the two formulations were bioequivalence.