Objective: Longxuejie colon-target tablet were prepared and investigated its in vitro release property. Method: Prepared core tablet containing Dranaena cochinchinensis

this colon-target tablet was prepared by hydroxypropylmethylcellulose

ethylcellulose and polyacrylic resin Ⅱ.Coating formulation was established with investigating drug release by single factor test

and orthogonal design was used to optimized coating formulation. Result: Optimal coating formulation was 3% weight gain of swelling coating layer

2% weight gain of enteric coating layer

polyacrylic resin Ⅱ-ethylcellulose 1: 10

colon-target tablet had a lag time of 6 hours and cumulative release quantity reached to 80% within 5 hours. Conclusion: Longxuejie colon-target tablet had colon-release characteristics

and could achieve the purpose of treatment of colon site disease.