The objectives of this study are to prepare resveratrol loaded mixed micelles composed of poloxamer 403 and poloxamer 407, and optimize the formulation in order to achieve higher drug solubility and sustained drug release. Firstly, a thin-film hydration method was utilized to prepare the micelles. By using drug-loading, encapsulation yield and particle size of the micelles as criteria, influence of three variables, namely poloxamer 407 mass fraction, amount of water and feeding of resveratrol, on the quality of the micelles was optimized with a central composite design method. Steady fluorescence measurement was carried out to evaluate the critical micelle concentration of the carriers. Micelle stability upon dilution with simulated gastric fluid and simulated intestinal fluid was investigated. The in vitro release of resveratrol from the mixed micelles was monitored by dialysis method. It was observed that the particle size of the optimized micelle formulation was 24 nm, with drug-loading 11.78%, and encapsulation yield 82.51%. The mixed micelles increased the solubility of resveratrol for about 197 times. Moreover, the mixed micelles had a low critical micelle concentration of 0.05 mg · mL(-1) in water and no apparent changes in particle size and drug content were observed upon micelles dilution, indicating improved kinetic stability. Resveratrol was released from the micelles in a controlled manner for over 20 h, and the release process can be well described by Higuchi equation. Therefore, resveratrol-loaded poloxamer 403/407 mixed micelles could improve the solubility of resveratrol significantly and sustained drug release behavior can be achieved.

Objective:To research the rule of melatonin nasal absorption.Methods: The stability of melatonin in rat nasal wash was studied, after that the in situ rat nasal recirculation methods were used as experimental animal model to study the rule of melatonin nasal absorption.Results:Melatonin was stable in rat nasal wash, its absorption in nasal cavity accorded with first order kinetic equation. The absorption rate constants did not vary with melatonin concentrations.Conclusion:The mechanism of melatonin nasal absorption is passive diffusion, the average absorption rate constant is 1.054?10 -2 min -1 .

Objective: To analyze vaccination situation of oral live attenuated rotavirus vaccine (LLR strain) among children from six provinces in China. Methods: In 2014, we selected 12 counties in Guangdong, Jiangsu, Chongqing, Jiangxi, Heilongjiang and Gansu provinces by using stratified cluster random sampling method and extract information of children born from January 1, 2008 to December 31, 2012 from Children's Immunization Information System. We investigated ten children of each birth cohort in each county by checking the vaccination certification, and a total of 606 children were investigated. A survey was conducted to check the information of the children's vaccination certification with the data of Children's Immunization Information System by questionnaire including the basic information (province, county, name, gender, birth date, etc) and the rotavirus vaccination (vaccination date, dose, etc) to analyze the rotavirus vaccination situation. Results: 340 of 606 children were male. There were 121, 124, 122, 119 and 120 children born in 2008-2012, respectively. The proportions of the first and the second dose of rotavirus vaccination were 32.8% (199) and 9.7% (59). The proportion of the third dose of rotavirus vaccination among children born between 2008 and 2010 was 3.5% (13) since children born in 2011 and 2012 did not reach the age of third dose vaccination. The proportion of the first dose of rotavirus vaccination in high, middle and low per capita disposable income areas was 45.0% (91), 37.7% (77) and 15.5% (31) respectively (χ²= 43.15, P<0.001). Among 199 children vaccinated with the first dose of vaccine, the vaccination age mainly concentrated in 2 to 21 months, of which the peak was 5 to 13 months (66.8%, 133). The intervals between 2 doses of vaccination were mainly from 12 to 13 months (42.4%, 25) among the 59 children who received at least 2 doses of vaccine. In the 13 children vaccinated with 3 doses, the intervals between the second and the third dose were 12 months (5). Of the 271 doses of rotavirus vaccine vaccinated during 2008-2014, 34.7% (94 doses) were vaccinated in June-August, 88 were vaccinated simultaneously with 18 other vaccines, accounting for 32.5% of the total. Of the 18 other vaccines, inactivated vaccines such as diphtheria vaccine (30 doses), Hib vaccine (14 doses), group A meningitis vaccine (10 doses) were predominant. Conclusion The proportion of rotavirus vaccination was low and the vaccination age was relatively late. The vaccination mode was different from the recommendation of WHO. It is recommended that routine immunization of rotavirus vaccines should be carried out in early-months of children.