Preparation and Evaluation in vivo and in vitro of Clenbuterol Hydrochloride Sustained-release Bilayer Tablets

OBJECTIVE To prepare clenbuterol hydrochloride sustained-release bilayer tablets and study its pharmaceutical characteristics in vivo and in vitro.METHODSHPMC and EC mixed matrix were used to prepare clenbuterol hydrochloride sustained-release bilayer tablets by direct compression technique and wet granulation technique.The release characteristics in vitro and pharmacokinetics in dogs of clenbuterol hydrochloride sustained-release bilayer tablets were investigated.RESULTSThe drug dissolution of sustained-release bilayer tablets was consistent with Higuchi equation.The peak levels(Cmax) after administration of sustained-release bilayer tablets and reference tablets were(5.86±0.33) and(11.43±0.64) ng·mL-1 at(3.17±0.73) and(2.02±0.35) h,respectively.The mean elimination half lives(t1/2) were found to be(11.90±1.42) and(6.18±0.81) h,respectively.AUC0-t were calculated to be(65.08±2.63) and(68.00±2.89) ng·h·mL-1,respectively.CONCLUSIONThe clenbuterol hydrochloride sustained-release bilayer tablets exhibited both sustained-and rapid-release characteristics in vitro.The calculated MRT of sustained-release bilayer tablets was significantly more than that of reference tablets.There existed correlation between the in vitro release and in vivo absorption.