Bioequivalence and pharmacokinetics of ribavirin buccal tablets in healthy volunteers

AIM:To determine ribavirin in human plasma by an LC/MS/MS method and to study the bioequivalence and pharmacokinetics of reference and test ribavirin formulations.METHODS:A double-phased stochastical crossover study design was conducted.18 healthy volunteers were given a single dose of 80 mg ribavirin of reference and test formulations.The drug was extracted from collected plasma and analyzed by LC/MS/MS.The pharmacokinetic parameters as well as relative bioavailability were measured.RESULTS:The calibration curve was linear within the range of 2-500 ng/mL(r2=0.9944).The average recovery was more than 90%.The average RSD within 3 days and between 3 days were all less than 10%.The major pharmacokinetic parameters tmax,Cmax,t1/2,AUC0-72 and AUC0～∞ of reference and test ribavirin formulations were(1.1±0.5)and(1.1±0.4)h,(249±89)and(232±65)ng/mL,(34±11)and(34±11)h,(2828±1215)and(2685±1096)ng·h·mL-1,(3600±1568)and(3416±1379)ng·h·mL-1.The relative bioavailability of test buccal tablet was(106±16)%.CONCLUSION:The method is more simple,more accurate and much more sensitive.There is no significant difference between the main pharmacokinetic parmeters of two formulations of ribavirin(P0.05),they are bioequivalent.