Study On The Enteric-coated Sustained Released Tablets Of Tiopronin

In this paper,tiopronin has been selected as the model to prepare enteric-coated sustained released tablet.the sustained time is 24 hour.Then,the in vivo intestinal absorption pharmacokinetic study of this sustained released tablet was performed in rats.In this reaserch,kinds of Hydroxy propyl methyl cellulose(HPMC),Hydrosy propyl cellulose(HPC)were used as the matrix material of the core tablet,Eudragit was employed as the enteric coating materials.In the preparation of tiopronin enteric-coated sustained released tablet for the first time,overcomed the weakness of hydrophilic drug released fast,and discussed the factors of enteric-coated sustained released tablet.The effects of many factors included the prescription of core tablet,arts of preparing tablet and in vitro release were investigated.Based on the single-factor experiments,the different of sustained matrix material,the prescription of enteric-coated material and film thickness were investigated,then the optimized formulation was confirmed.The tablet made by the optimized prescription was proved to have 24h excellent diffuse-corro release characteristic(r=0.9976),the cumulative release of tiopronin is up to 95%and the reproducibility of different batcher was good.It is the first time to study the in vivo intestinal absorption pharmacokinetic of tiopronin.The single pass perfusion method in rat was employed in the intestinal absorption experiment.Using the absorption constant(ka)and apparent absorption coefficient(Papp)as index to investigate the characteristic of the in vivo intestinal absorption dynamics.In this paper,the perfusion speed,drug concentration and absorption site were studied.The result is the perfusion speed has significant difference,the drug concentration has none effect within a certain extent.the conclusion is the absorption of Tiopronin is good in intestinum tenue.