ABSTRACT
Objective To prepare a thermosensitive in situ gel system containing berberine hydrochloride for ocular use. Methods The in situ thermosensitive gel system of berberine hydrochloride was prepared by Poloxamer 407 (P407) and Poloxamer 188 (P188) as thermosensitive materials,the formulation was optimized by determining solution-gelation conversion temperature by using stirring method. The content of berberine hydrochloride was determined by HPLC. Results The gelation temperature of in situ thermosensitive gel containing berberine hydrochloride formulations lowered as the P407 concentration increased,as the P188 concentration increased gradually the gelation temperature initially increased to maximum and then decreased. The gelation temperature all increased after simulated tear fluid (STF) dilution. The fitted equation was established for the gelation temperature with the concentration of Poloxamer solutions after diluted by STF. An optimized formulation by Design-Expert software was freely flowing liquid at 29.7 ℃ and convert to a firm gel at 34.5 ℃ after STF diluted. Conclusion In situ thermosensitve gel system complies with the requirement for ophthalmic application and shows great potential in ocular application.