OBJECTIVETo prepare quercetin nanostuctured lipid carriers (QT-NLC), and detect their physicochemical properties.

METHODQT-NLC was prepared by emulsification ultrasonic dispersion method, and the optimum prescription was screened out by orthogonal design. Transmission electron microscope was used to observe QT-NLC morphology. Granulometer was applied to determine zeta potential, particle size and distribution. DSC was adopted for phase analysis. Centrifugal ultra-filtration method was used to determine entrapment efficiency. Dialysis method was adopted to detect drug release in vitro of preparations.

RESULTQT-NLC prepared under optimum conditions was mostly spherical grains, with the average particle size of (175 +/- 25) nm, which were distributed evenly, and zeta potential was (-23 +/- 0.3) mV. DSC results indicated that the drug was dispersed in nano-particles in a non-crystalline state, with an entrapment efficiency of (95.43 +/- 0.23)% and a drug-loading capacity of (2.38 +/- 0.24)%. The in vitro drug release was 32.2% in 2 hours, which was followed by a sustained release.

CONCLUSIONEmulsification ultrasonic dispersion method is applicable for preparing QT-NLC, as nano-particles are distributed evenly, with good reliability. This processing technology is safe, reliable and highly reproducible.

Delayed-Action Preparations ; Drug Carriers ; Emulsions ; Lipids ; chemistry ; Nanoparticles ; chemistry ; ultrastructure ; Particle Size ; Quercetin ; chemistry

Objective To evaluate effects of soles with different hardness on kinematic parameters of human lower extremity during walking by conducting kinematic analysis on subjects walking with soles of different hardness. Methods Subjects were required to wear 3 kinds of shoes with soles of different hardness and walk on the treadmill at the speed of 6 km/h. Vicon infrared camera system was used to capture the motions of subjects during walking, and kinematic parameters such as heel height, toe height, knee angle and ankle angle were collected for experimental analysis. Results Compared with the other shoes, the gait cycle was increased when subjects wearing soft-soled shoes, with the smallest angel of the forward pendulum of crus. The forward pendulum of thigh was the smallest and the back pendulum was the largest when subjects wearing medium-hardness shoes. The forward pendulum of thigh was the largest and the back pendulum was the smallest when subjects wearing hard-soled shoes. The time of swing phase was relatively stable. Conclusions Soft-soled shoes are more suitable for slow walking during a short period, while medium-hardness shoes have the smallest impact on lower extremity kinematics during walking for a long period, and hard-soled shoes are suitable for fast walking during a short period.