Studies on Pharmacokinetics of Rhubarb Acid Enteric-coated Sustained-release Pellets in Rabbits

Objective:To study the pharmacokinetics and bioequivalence of self-prepared rhubarb acid enteric-coated sustained-release pellets,and compare the pharmacokinetics of rhein between rhubarb acid enteric-coated sustained-release pellets and solution,make clear the pharmacokinetic character of the sustained release preparation in vivo.Method:Ten rabbits were given a single oral dose of 35 mg·kg-1 of self-prepared rhubarb acid enteric-coated sustained-release pellets(test preparation) and the sodium alginate solution of rhein(reference preparation) in a crossover study.HPLC was applied to determine the plasma concentrations of rhein before and 0.5,1,2,3,4,6,8,9,10,12,24,28,32,36 h after administration of the medicine.The pharmacokinetic parameters were calculatedand statistically analyzed.Result:The plasma concentration curves of both the sustained-release matrix pellets and the sodium alginate solution of rhein had one peak.The main pharmacokinetic parameters of test preparation were as follows:tmax(9.73±0.68)h,Cmax(3.00±0.81) g·L-1,AUC0~∞(59.21±4.35) mg·L-1·h-1,MRT(21.12±1.12)h;and those of reference preparation were as follows:tmax(4.17±0.12)h,cmax(2.71±0.74) g·L-1,AUC0~∞(39.72±3.11) mg·L-1·h-1,MRT(9.33±2.08)h respectively.Conclusion:Compared with the sodium alginate solution of rhein,the self-prepared rhubarb acid enteric-coated sustained-release pellets have better bioavailability.