Preparation of thermosensitive intestinal gels of Houttuynia cordata volatile oils HPCD inclusion compound / 中成药

AIM To prepare the thermosensitive intestinal gels of Houttuynia cordata Thunb volatile oils hydroxypropyl-β-cyclodextrin (HPCD) inclusion compound.METHODS For the gels prepared by cold dissolving method,poloxamer 407 consumption and poloxamer 188 consumption were taken as influencing factors,together with phase transition temperature as an evaluation index,central composite design-response surface method was applied to optimizing the formulation.With 2-undecanone as an index component,the gels' dissolution rate and in vitro release rate were investigated by non-membrane dissolution method and dialysis bag method respectively,whose stability was then evaluated by high temperature (40,60 ℃),low temperature (4 ℃),strong light [(4 500 ±500) 1x] and acceleration (three months) tests.RESULTS The optimal conditions were determined to be 20.61％ for P407 consumption and 3.03％ for P188 consumption,the phase transition temperature was 36.5 ℃.Within the time range of 30-150 min,the HPCD inclusion compound gels exhibited higher accumulative dissolution rate than the volatile oils gels,which tended to be consistent in 150-210 min,but the former exhibited higher accmulative release rate (0-50 h) than the latter all the time.The obtained gels showed good stability at low temperature,whose appearance,characteristic (except for high temperature) and pH were stable at high temperature,strong light and acceleration with obviously decreased 2-undecanone content.CONCLUSION The thermosensitive intestinal gels of Houttuynia cordata Thunb volatile oils HPCD inclusion compound should be stored at low temperature (4 ℃).

Preparation and in vitro Release of Norfloxacin Thermosensitive in Situ Gel for Vaginal Use / 中国药师

Objective:To prepare norfloxacin thermosensitive in situ gel and investigate its in vitro drug release behavior. Meth-ods:Poloxamer 407 and poloxamer 188 were used as the matrix of norfloxacin thermosensitive in situ gel,and the gel was prepared by a cold dissolving method. The formula was optimized by a central composite design-response surface method. In vitro drug release be-havior of norfloxacin thermosensitive in situ gel was studied as well. Results:Within a certain concentration range, the gelation tem-perature decreased gradually with the amount increase of poloxamer 407, and that increased gradually with the amount increase of poloxamer 188. The optimal formula was as follows:the concentration of poloxamer 407 was 20.6%(w/v),and that of poloxamer 188 was 5.7%(w/v),which obtained suitable gelling temperature. The release of norfloxacin from the thermosensitive in situ gel reached up to (87.5% ± 5.4% 7 in 6 h. Conclusion: Norfloxacin thermosensitive in situ gel has excellent temperature sensitivity, and can slow down the drug release,which shows potential use for vaginal drug delivery system.