ABSTRACT
OBJECTIVE:To study the bioequivalence of Levodopa micro-capsule floating tablets in Beagle dogs after multi-dose administration. METHODS:6 dogs were collected and divided into Levodopa micro-capsule floating tablets group and Com-pound levodopa preparation group (Benserazide tablet,reference preparation). They were given levodopa 200 mg intragastrically, every 8 h,for consecutive 4 day. In two-period crossover test,HPLC method was established to determine the concentration of le-vodopa in dog. The pharmacokinetic parameter,bioequivalence and plasma concentration fluctuation of steady state were calculated. RESULTS:The main pharmacokinetic parameters of Levodopa micro-capsule floating tablets and reference preparation were as that cmax were(4.23±0.75)and(8.47±1.18)μg/ml;AUC0-∞ were(12.18±1.16)and(13.81±2.12)μg·h/ml;tmax were(1.83±0.26) and(0.67±0.13)h,respectively. 90% confidence intervals for the geometric mean ratio of AUC0-∞ for test and reference prepara-tion were 80.61%-97.90%,and that for cmax were 42.75%-57.63%,respectively. There was statistical significance in tmax between test and reference preparation. Degree of fluctuation of test and reference preparation at steady state were(283.914±43.217)% and (506.489±78.965)%,and fluctuation coefficient were(177.463±7.873)% and(187.405±1.650)%,respectively. The degree of fluctuation of test preparation was significantly less than that of reference preparation. CONCLUSIONS:Levodopa micro-capsule floating tablets show good sustained-release property,and are bioequivalent with reference preparation in absorption after multiple dose administration. It also has lesser fluctuation of blood concentration.