ABSTRACT
AIM To prepare thermo-sensitive diammonium glycyrrhizinate binary liposome gel and to evaluate the in vitro drug-release behaviors.METHODS Cold dissolution method was adopted in the preparation of gel.With gel transition temperature as an evaluation index,amounts of Poloxamer 407 (P407),Poloxamer 188 (P188) and polysaccharides from Bletillae Rhizoma as influencing factors,central composite design-response surface method was applied to optimizing the formulation.Then the in vitro drug-release behaviors were evaluated by HPLC and Franz vertical diffusion cell method.RESULTS The optimal formulation was determined to be 18％ for P407 amount,4％ for P188 amount,and 0.6％ for polysaccharides' amount,the gel transition temperature was (37.5 ± 0.3) ℃.The accumulative release rate of obtained thermo-sensitive binary liposome gel was (65.52 ± 0.63) ％ within 48 h,which showed more obvious sustained-release effect as compared with liposome and thermosensitive gel.CONCLUSION Thermo-sensitive diammonium glycyrrhizinate binary liposome gel can reduce drug-release rate and increase its retention time in the rectum.