Abstract: AimTo prepare the compound danshen pH-dependent delayed release pellets and filled them in capsules and then study thier pharmacodynamics. MethodsThe pH-dependent delayed release pellets were prepared by coating with HPMC, Eudragit L-30D-55 and Eudragit L100-Eudragit S100 (1∶6), separately, and mixed in proper proportion to prepare the two pH-dependent delayed release systems T1 and T2. The release of delayed release pellets was determined according to the method of China Pharmacopoeia (2000) in the simulated gastrointestinal pH conditions. The pharmacodynamic parameters were evaluated by serum pharmacology method. ResultsThe compound danshen pH-dependent delayed release pellets were prepared with the characteristics of pH dependent delayed release profile in vitro. In single oral dose,the pharmacodynamic parameters of rapid release tablets R E_max (%) and T_max (h) were 34.63% and 0.58 h, respectively. T_maxs of delayed-release pellets T1 and T2 were extended to 2.42, 3.17 h and E_maxs (%) were declined to 13.57%, 14.52%. The relative bioavailabilities of T1 and T2 were 99.3%, 133.6%, respectively. In multiple oral doses of R the pharmacodynamic parameter of DF was 7.32 and those T1, T2 DF were 3.40, 3.03, respectively. ConclusionThe compound danshen pH-dependent delayed release capsules have characteristics of pH dependent releasing in vitro and characteristics of delayed release in vivo. In multiple oral doses the DF of delayed release capsules was lower than that of rapid release tablet at steady state.