Objective:To prepare EC impermeable capsule bodies for pulsatile drug delivery system and evaluate the effects of different species dichlormethane mixed solvent and concentration of EC(ethyl cellulose) solution on EC capsule bodies. Methods:The EC impermeable capsule body was prepared by filling method with the EC solution composed of different dichlormethane mixed solvent. The influencing factors on the forming of the EC capsule and the inosculation between the EC capsule and corrosion tablet were investigated by dissolution tester

hardness tester

multifunction pachometer and Sliding caliper. Results:The EC capsule body that was prepared by 11.5%(w/v) 45cp EC solution using the mixedsolvent composed of dichlormethane/ethanol absolute/ethyl acetate(4/0.8/0.2) inosculated well with the corrosion tablet and met the requirements of the pulsatile drug delivery system. Conclusions:The solvent and concentration of the EC solution have great impact on the forming and characterisitcs of the capsule bodies

by optimazing the preparing methods

requirements of the oral pulsatile drug delivery system can be met.