Thermosensitive in Situ Gel Based on Poloxamer System Containing β-cyclodextrin for Sustained Release of Propolis in Vitro

［Abstract］Objective　To optimize the technology of preparation propolis wrapped with cyclodextrin by using the orthogonal design method，and to study the in vitro drug release rate in the thermosensitive in situ Gel based on Poloxamer System．Methods（1）The amount of total flavone in Yunnan propolis extract was determined with ultraviolet spectrophotometry.（2）By using the orthogonal design method and saturated aqueous solution，we optimized the technology of preparation propolis wrapped with β-cyclodextrin.（3）We assayed the inclosure rate and the recovery rate of propolis，and optimized the technology. （4）We studied the sustained release effect of the propolis wrapped with cyclodextrin which in situ gel based on poloxamer system，using in vitro drug release as the ultimategoal．Results　The optimum preparation conditions were determinted through orthogonal experiment：ratio of propolis to β- cyclodextrin was 1 to 2，bathing temperature was 70 ℃ and milling time was 1.0 h．Then the inclusion rate reached 43.75%，the recovery rate reached 32%．In artificial saliva，the target drug could sustained release more than 99% within 16 h，the drug sustained release effect is better than the non-β-cyclodextrin with propoils．Conclusion　The release rate of propoils with β-cyclodextri from hydrogel becomes slow and controls delirery over 16 hours.