[Preparation and evaluation of Shedan in situ forming gel based on ocular characteristics].

To develop an ophthalmic preparation of Shedan, an in situ forming gel was prepared with the formulation containing 18% of poloxamer 407 and 5% of poloxamer 188 by response surface designs plus central composite designs. The rheology results showed that LVE range gamma should limited within 0.5%, Shedan high-frequency region, and the thixotropy recovery time is less than 5 seconds. The phase transition temperature was 33.25 °C according to curve of storage modulus and loss modulus determined by temperature scanning. Surface tension and osmometer of it determined by surface tension meter and dew point osmometer were 36.43 mN · m(-1), and 320.6 mOsm · kg(-1), respectively. Fluorescein sodium was selected as the marker to monitor the corneal residence time, and the results showed that Shedan gel could prolong drug residence for 180 min. In line with zero-order kinetics, releases of muscone and salvianolic acid B in vitro depends on gels erosion. The results of rabbit ocular irritation experiments suggested that Shedan in situ forming gel was biocompatible and nonirritant. In conclusion, a novel Shedan in situ forming gel was developed and characterized for potential drug treatment of retinal vein occlusion.

[Optimal extraction of nuciferine and flavone from lotus leaf based on central composite design and response surface methodology].

OBJECTIVE: To optimize the process of extracting effective constituents from lotus leaf. METHOD: Independent variables were ethanol concentration reflux time and solvent fold, dependent variables were extraction rates of nuciferine and flavone in lotus leaf, central composite design and response surface methodology were used for optimization of extraction of lotus leaf. RESULT: The optimum conditions of extraction process were 75% -80% ethanol, 2-3 hours for reflux, 20-25 fold solvent and 2 times for extraction. Bias between observed and predicted of rates of nuciferine and flavone values were 5.53%, -6.02%, respectively. CONCLUSION: The values observed and predicted were close to each other, which proved that the optimization of of extraction of lotus leaf by central composite design and response surface methodology was reasonable and successful.

[Comparative study on in vitro drug-release between Tuizhang ophthalmic gel and Tuizhang oculentum].

OBJECTIVE: To prepare tuizhang gel to cure cataract, the characteristics of Tuizhang gel on the drug-releasing in vitro were evaluated by compared with Tuizhang oculentum. METHOD: The emodin and chrysophanol in the releasing mediator were determined by HPLC, and the drug releasing characteristics of Tuizhang gel and Tuizhang oculentum were studied by bag filter method. RESULT: The emodin and chrysophanol in Tuizhang gel released (98.3, 1.1)%, (95.8, 1.8)% within 24 hours, respectively, while those in tuizhang oculentum released (10.62, 0.7)%, (10.46, 0.4)%, respectively. The emodin and chrysophanol in Tuizhang gel released more quickly and completely than in Tuizhang oculentum, so Tuizhang gel has enhanced the bioavailability. CONCLUSION: The Tuizhang gel is characterized by slow-release to some degree, and it shows a promising future on ophthalmic drug delivery.

[Studies on preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex].

OBJECTIVE: To find the best condition of the preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex. METHOD: L9(3(4)) table was used to examine the effects of 4 factors, and the inclusion rate of each test was determined of orthogonal test. RESULT: The best condition was:oil:beta-cyclodextrin:water = 1:8:60 (mL:g:mL), stirring for 1 hour at 80 degrees C. CONCLUSION: The complex prepared on the condition aforementioned is stable and stirring has a highest inclusion rate.

[Comparative studies on isolation and purification of Chinese medicine decoction].

OBJECTIVE: To evaluate different methods by treating water-decocted liquid of 6 Chinese medical herbs and 4 co-prescription respectively with alcohol, ultrafilter, macroporousresin and clarifier. METHOD: The contents of target component in those extracts were determined with HPLC or titration, and quantitative and qualitative determination of the impurity components, such as polysaccharide and protein, was made. RESULT: Each method showed its advantages and disavantages. CONCLUSION: Different method can be chosen according to the clinical and preparation demands or the characteristic of components.