OBJECTIVES: To develop a two-dimensional liquid chromatography method to determine the content of vitamin D₃ in cod liver oil preparations. METHODS: The samples were prepared by saponification and extraction, and the content of vitamin D₃ was determined by two-dimensional liquid chromatography with dual-pump-single-valve switching dual detectors. The chromatographic column, capture device, and detection wavelength were optimized; the linearity, system suitability, recovery rate, repeatability and sample stability of the method were investigated, and further validated in actual sample determination. RESULTS: A column switching two-dimensional chromatography method was developed. In the first chromatography dimension, an Agilent PoroShell SB-C8 (50 mm×4.6 mm, 2.7 μm) column was used with acetonitrile-water as the mobile phase with gradient elution at a flow rate of 1.0 mL/min and detection wavelength as 264 nm. An Agilent Zorbax SB-C18 (150 mm×3.0 mm,1.8 μm) column was used in the second chromatography dimension with acetonitrile as the mobile phase at a flow rate of 0.42 mL/min, and detection wavelength as 264 nm. In determining vitamin D₃ content, there was a good linear relationship in the concentration range. The system suitability, recovery rate, repeatability and sample stability all met verification requirements. CONCLUSIONS The two-dimensional liquid chromatography method developed in this study is accurate, reproducible and simple, and can simultaneously separate pre-vitamin D₃, trans-vitamin D₃, vitamin D₃, and tachysterol D₃.
Cholecalciferol/analysis* ; Cod Liver Oil/chemistry* ; Chromatography, Liquid/methods* ; Chromatography, High Pressure Liquid/methods*

Objective To develop a method for detection of avanafil and flibanserin adulterated in health food by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Methods The separation and analysis were performed on an Agilent Eclipse Plus C18 column(2.1 mm×100 mm,1.8 μm),with a mobile phase of acetonitrile and 0.1%acetic acid(containing 20 mmol·L-1 ammonium acetate)(60:40).Electrospray ionization(ESI) source was applied and operated in positive mode.Multiple reaction monitoring(MRM) mode was used to quantify avanafil and flibanserin.Results The assay linearity of avanafil and flibanserin were confirmed in the range of 2-20 ng·mL-1(r2>0.99).The extraction recoveries varied from 94.6% to 110.0%,and the precision of RSD was <5.0%.The limits of detection were 0.21 and 0.42 μg·kg-1 for avanafil and flibanserin,respectively.Conclusion The method was specific,sensitive and accurate.Therefore,it can be used to detect avanafil and flibanserin which were illegally added in health food.

Objective To establish the quality standard of Xiao'er resuqing gantules.Methods Rhei Radix et Rhizoma,Bupleuri Radix,Forsythiae Fructus,Puerariae Lobatae Radix in the granules were qualitatively identified by the method of thin layer chromatography (TLC).The content of baicalin was analyzed by the method of high performance liquid chromatography (HPLC).Results There were good specificities of the TLC method to identify Rhei Radix et Rhizoma,Bupleuri Radix,Forsythiae Fructus,Puerariae Lobatae Radix.The linear range of baicalin was 0.116 2-1.743 0 μg (r =1.000 0).The average of recovery and RSD were 100.61％,0.79％ (n =6),respectively.Conclusion The method established in this study is simple,accurate,reliable and suitable to be applied to quality control for the preparation of Xiao' er resuqing granules.

OBJECTIVETo establish a method for determination of 7-ethyl-10-hydroxycamptothecin (SN-38) in microdialysates from rat brain.

METHODSThe concentrations of SN-38 were measured by LC-MS/MS method with Agilent Eclipse Plus C18 (2.1 mm ×100 mm, 1.8 μm) reversed phase column using acetonitrile-0.1% methanoic acid as mobile phase with gradient elution at a flow rate of 0.3 ml/min and temperature at 35 degree. Multiple reaction monitoring using the precursor to product ion combinations of m/z 393.1→349.1 was performed to detect SN-38 in microdialysates from rat brain.

RESULTSBlank microdialysate had non-interference. The method was linear over the concentration range of 0.1015-1015 ng/ml (r=0.9995); and the lower limit of quantification (LOQ) was 0.1015 ng/ml. The recovery of assay for SN-38 ranged from 97.54%-100.60%. The intra- and inter-day precision and stability were both well. The concentrations of SN-38 in brain microdialysates presented pharmacokinetics process and achieved the peak after 220 min.

CONCLUSIONThe fully validated LC-MS/MS analytical method has high specificity and sensibility, which can be used effectively to analyze SN-38 in microdialysates from rat brain.

Animals ; Brain Chemistry ; Camptothecin ; analogs & derivatives ; analysis ; Chromatography, Liquid ; methods ; Male ; Microdialysis ; Rats ; Rats, Sprague-Dawley ; Sensitivity and Specificity ; Tandem Mass Spectrometry ; methods

Objective To investigate the serum concentration of vascular endothelial growth factor (VEGF) and its soluble receptor 1 (sFlt-1) in patients with systemic lupus erythematosus (SLE) and its correlation with clinic and pathologic parameters.Methods serum levels of VEGF and sFlt-1 in a group of 60 patients with SLE and 30 healthy controls were assessed by ELISA.Results The VEGF and sFlt-1 serum levels were higher in active SLE group than the control group (P＜0.01).The VEGF/sFlt-1 ratio in the control group was lower than that in the active SLE group.inactive SLE group and LN group (P＜0.01).Particularly the ratio increased in WHO class Ⅴ LN group compared to WHO classⅡ,Ⅲ,Ⅳ LN group (P＜0.05).The semm level of sFlt-1 was correlated to proteinuria (rs=0.6244,P＜0.01) and ESR (rs=0.4235,P＜0.01) and the serum levels of VEGF and sFlt-1 were correlated to the systemic lupus erythematosus disease activation index (SLEDAI) (rs=0.5046,P＜0.01 and rs=0.5152,P＜0.01,respectively).The serum level of VEGF was correlated with renal tissue activation index (RAI) (rs=0.3386.P＜0.05) and the serum levels of VEGF and sFlt-1 were not correlated to blood pressure,serum creatine,blood ureanitmgen,C3,C4,C-reative protein.The muhi-factors stepwise regression analysis indicated that serum VEGF was positively correlated with SLEDAI (R2=0.1 75,P＜0.05),serum sFlt-1 was positively correlated with ESR and proteinurine (R2=0.497,P＜0.05).Conclusion Serum VEGF and sFlt-1 are elevated in patients with active SLE and they can reflect the activity of the disease.The overcxpression of serum VEGF might be correlated to the proliferated glomerulonephritis and the overexpression of sFlt-1 contribhtes to proteinurla.The imbalance between these two factors may act an important role in SLE pathogenesis.

Objective To prepare ligustrazine-chitosan microspheres and to investigate the drug release behavior in vitro. Methods Microspheres were prepared using the spray drying method.The encapsulation efficiency was used to evaluate the influence of different formulation and preparation factors,the formulation was optimized by L9(34) orthogonal design.Results The optimal formulation and preparation factors were as follows: chitosan concentration(0.01 g/mL),ratio of chitosan to ligustrazine(1∶4),inlet temperature(120 ℃),air flow rate(500 L/h).The optimized microspheres had a spherical shape,the loading capacity was(18.60?0.15)%,entrapment efficiency was(93.01?0.76)%,the average diameter was(10.69?0.64) ?m.The drug release profile in vitro could be described by Higuchi equation Q=19.798 t1/2+25.209(r=0.997) at 1-15 h,which showed the prepared microspheres obviously had the sustained release effect.Conclusion The encapsulation efficiency of ligustrazine-chitosan microspheres is higher,the preparation method is simple,and the process is stable.It will provide the basis for realizing the industrialization in Chinese materia medica microspheres.