Preparation of Carboxymethyl Zein Aspirin Enteric-coated Pellets and Its Release Rate in vitro

OBJECTIVE:To prepare Carboxymethyl zein aspirin enteric-coated pellets,and to investigate pharmacokinetic characteristics of it in rats. METHODS:Carboxymethyl zein was used as enteric-coated material and mixed with aspirin with ratio of 2 ∶1 using ethanol as adhesive. Carboxymethyl zein aspirin enteric-coated pellets were prepared by extrusion spheronization method.Using Aspirin pellets as reference preparation,48 h pharmacokinetic characteristic and 4 h in vitro drug release of Carboxymethyl zein aspirin enteric-coated pellets as test preparation were investigated in rats after intragastric administration of test preparation 15mg/kg(n=5). RESULTS:Prepared pellets was 1 mm in particle size and 3 mg/pellet in specification. The pharmacokinetics of both reference and test preparations were in line with two-compartment model. Main pharmacokinetic parameters of reference preparations vs. test preparations:t1/2β:(12.63±0.60)h vs.(2.42±0.61)h;tmax:(11.07±1.10)h vs.(3.41±0.84)h;cmax:(34.45±5.33)μg/ml vs.(45.78±3.30)μg/ml;AUC0-∞:(613.52±41.14)μg·h/ml vs.(550.69±34.44)μg·h/ml. Compared with reference preparation,t1/2 β,tmaxand AUC0- ∞of test preparation increased significantly,while cmaxdecreased greatly(P0.05). 2 h accumulative release rate of reference and test preparation were 87% and 1.7%,and test preparation was released completely within 3 h. CONCLUSIONS:Prepared Carboxymethyl zein aspirin enteric-coated pellets which are up to the requirements of enteric-coated preparation are prepared successfully.