The mechanical properties and moisture permeability of Eudragit L100/S100 free films affected by plasticizers and membrane materials ratio

The free membrane of Eudragit L100/S100 which is pH-sensitive, colon-specific was prepared by plane casting films.  The film humidity, species and amount of plasticizers, the ratio of membrane material was investigated.  The rate of membrane permeability and mechanical properties were used as indicators of orthogonal experiment, and its related properties were studied.  The results show that the mechanical properties of the membrane and phragmoid capacity are the best when 30% TEC was used as plasticizer; the ratio of membrane material have little effect on the rate of membrane permeability and mechanical properties.  By adjusting the species and amount of plasticizers, the ratio of Eudragit L100/S100, the free membrane which is colon-specific can be obtained.