Objective:To explore the effects and mechanism of liraglutide on nitrogen monoxide (NO) release in human umbilical vein endothelial cells in the state of hypoxia and high glucose.Methods:A model of hypoxia and high glucose was established by using isolation and culture of primary human umbilical vein endothelial cells (HUVECs) in vitro.HUVECs were incubated with liraglutide and/or exendin (9-39) for 4 h.The metabolic ability of cells was detected by MTT assay,the activity of lactate dehydrogenase (LDH) was measured by a colorimetric method,and the levels of extracellular NO were measured by a nitrate reductive enzymatic method.The endothelial nitric oxide synthase (eNOS) mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR).Results:Compared with the model group,liraglutide could significantly increase cell metabolic ability,reduce LDH release,increase NO release and eNOS mRNA expression (P<0.05 or P<0.01).The above effects of liraglutide were partly inhibited by glucagon like peptide-1 (GLP-1) receptor antagonist exendin (9-39)(P<0.05).Conclusion:Liraglutide can improve endothelial relaxation function in HUVECs in the state of hypoxia and high glucose in vitro.The effect might be related to up-regulating eNOS mRNA expression and promoting NO release.

Objective:To develop an HPLC method for determining the total ginkgo flavonoid in self-emulsifying drug delivery sys-tem. Methods:Effective chromatographic separation was achieved using a phenomenex C18 column (250 mm × 4. 6 mm, 5 μm) with a mobile phase composed of methanol and water (0.4% phosphoric acid) with the ratio of 50 ∶50 (v/v). The mobile phase was pumped using an isocratic HPLC system at a flow rate of 1. 0 ml·min-1 , the detection wavelength was 360 nm and the column temper-ature was 30 ℃. Results:The three components in the total ginkgo flavonoid were well separated by the proposed method. The linear relationship between the peak area and the concentration was promising within the range of 2. 0-40. 0 μg·ml-1 for quercetin, 3. 0-60. 0 μg·ml-1 for kaempferide and 2. 0-40. 0 μg·ml-1 for isorhamnetin. The mean recovery of quercetin, kaempferide and isorham-netin was 98. 4%, 99. 7% and 100. 5% with RSD of 0. 92%,0. 62% and 1. 24% (n=9), respectively. Conclusion:The method is specific and stable in the determination of total ginkgo flavonoid in self-emulsifying drug delivery system.

Objective:To prepare total ginkgo flavonoid self-emulsifying drug delivery system(TGF-SMDDS)and estimate its char-acteristics in vitro. Methods:The formula of TGF-SMDDS was optimized based on the solubility tests,formula compatibility and microe-mulsion area in the pseudo ternary phase diagram. The appearance,morphology,particle size,zeta potential and in vitro dissolution of TGF-SMDDS were investigated. Results:The formula was composed of oleoyl macrogolglycerides as the oil phase,Tween-80 as the sur-factant and XCF as the co-surfactant. The ratio of oil phase,surfactant and co-surfactant was 10 ∶ 6 ∶ 4. The drug loading was 10. 0 mg· g -1 . After mixed with water,TGF-SMDDS was formed a clear and transparent microemulsion with homogeneous small spheres as seen un-der a transmission electron microscope. The particle size and zeta potential of TGF-SMDDS was(87. 4 ±26. 7)nm and( -13. 1 ±1. 5) mV,respectively. The accumulative dissolution of TGF-SMDDS in pH1. 2 hydrochloric acid solution was(96. 1 ±4. 8)% in 45 min. Con-clusion:The TGF-SMDDS can significantly enhance the dissolution of TGF in vitro,which may be a potential effective preparation for TGF.

Objective: To optimize the formula of bromhexine hydrochloride dry powder inhalations (BH DPIs). Methods: BH DPIs were prepared by freezing-drying combined with an air-jet milling method. Three factors, including the weights of mannitol (X1), leucine (X2) and poloxamer 188 (X3) in the formula were known to be associated with the quality of BH DPIs. A central composite design was used to investigate the effects of the three factors on the response angle (Y1), fine particle fraction (FPF, Y3) and aerody-namic diameter (Y4). Response surface and overlay contour plot were delineated according to the best-fit mathematic models. Opti-mum formula was selected by overlay contour plot. Results: The quantitative relationships between the three factors and the three re-sponses were obtained. The optimal formula was mannitol﹕leucine﹕poloxamer 188 (2. 4: 2. 22: 0. 05) in the excipients. The pre-dicted and observed values of the optimum formula were similar. Conclusion: The multi-objective simultaneous optimization of the for-mula of BH DPIs is achieved by central composite design-response surface methodology.