Résumé
Objective To optimize the formulation of paeonol nanostructured lipid carrier (NLC) thermosensitive in situ gel through Box-Behnken response surface method; To investigate its release properties in vitro to provide references for the study of transdermal drug delivery system. Methods Taking mass fraction of poloxamer 407 and poloxamer 188 as the factors, the gelling temperature as the index, the mathematical relationship between the gelling temperature and two factors was established by binomial model and multivariate linear regression model. The Box-Behnken response surface method was used to optimize the formulation of paeonol NLC thermosensitive in situ gel, and the in vitro release characteristics of the preparation was investigated. Results There was a credible quantitative relationship between the gelling temperature and the 2 factors, and the binomial model was more reliable than the multivariate linear model. The best prescriptions of paeonol NLC thermosensitive in situ gel were 22.90% poloxamer 407 and 3.34% poloxamer 188; gelling temperature was (33.4±0.1)℃, and the cumulative release amount of paeonol in situ gel in 24 h was 51.19%. Conclusion This method is suitable for the formulation optimization of paeonol NLC thermosensitive in-situ gel, and the established mathematical model has good predictability. The optimized formulation can provide references for the development of paeonol transdermal preparation.
Résumé
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.