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Objective: To analyze and compare the difference of volatile components between Trifolium pratense and T. repens seeds.Method: The volatile components were extracted by the headspace solid phase microextraction (HS-SPME) method and analyzed by gas chromatography-mass spectrometry (GC-MS),and the relative contents of the components were calculated by the area normalization method.Result: Fourty six compounds were identified in the seeds of T. pratense,with a total peak area of 3.48×109 for the volatile components. The compounds with high content in this species were 1-octen-3-ol (30.24%),1-hexanol (11.94%),heptane,2,2,4,6,6-pentamethyl (11.00%),nonanal (7.74%),octanal (6.79%) and hexanoic acid (6.04%). 44 compounds were identified from the seeds of T. repens,with a total peak area of 6.37×109 for the volatile components. The compounds with high content in this species were 1-octen-3-ol (42.98%),heptadecane (14.47%),3-octanol (9.42%),n-caproic acid vinyl ester (8.82%) and pyrimidine-4,6-diol,5-methyl (6.59%). 20 components were commonly shared in the seeds of T. pratense and T. repens,but the content of each component was quite different. 1-octen-3-ol had the highest content in the common components. T. pratense seeds had 26 unique components,accounting for 54.85%of volatile components. T. repens seeds had 24 unique components,accounting for 46.79%of volatile components.Conclusion: The seeds of both T. pratense and T. repens have rich volatile components,but there are great difference in the variety,peak area and relative content of the volatile components between these two varieties
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AIM To investigate the distribution of volatile components and inorganic elements from Vernonia amygdalina Del..METHODS Volatile components and inorganic elements in different parts of V.amygdalina were analyzed and measured by HS-SPME-GC-MS and ICP-OES techniques.RESULTS Forty-four,sixty-seven,fifty-seven chemical compounds were identified from the root,stem and leaves of V.amygdalina,accounting for 83.9％,92.0％,83.9％ of the volatile components,respectively.Nineteen inorganic elements in total were detected,and the contents of As,Be,Bi,Co were too low to detect;The three inorganic elements with the highest content in root,stem and leaves were Mg,Al and Fe.CONCLUSION There are abundant volatile components and inorganic elements in V.amygdalina,with varying distribution in its different parts.
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To study the effect of value-added tax(VAT) based on the actual tax burden of public hospitals.It was found that the value-added tax burden rate varied,while the tax saving effect was undesirable.It suggested that the public hospitals should make efforts to curb the situation of "no reduction,but increase",and work well in tax planning.
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OBJECTIVE: To investigate the effect of copovidone (PVP/VA), hydroxypropylmethylcellulose acetate succinate (HPMCAS) and hydroxypropylmethylcellulose (HPMC) on drug dispersion and in vitro dissolution of solid dispersion by using nifedipine as model drug. METHODS: Nifedipine solid dispersion was prepared by hotmelt extrusion (HME) technology, and the drug dispersion was evaluated by differential scanning calorimetry (DSC) and dissolution test. RESULTS: DSC analysis results showed that nifedipine was amorphous in all HME extruders. Drug release from solid dispersion prepared with HPMCAS reached 100% in 30 min, but was only 75% for PVP/VA solid dispersion. Adding 5% HPMC E5 to PVP/VA extruders before dissolution test could raise the drug release from 75% to 90%. CONCLUSION: HPMCAS or combination of PVP/VA and HPMC E5 are desirable polymers for nifedipine solid dispersion.
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OBJECTIVE: To investigate the effect of polymers, including hydrophilic polymers and swelling aids, on floatability and dissolution of ciprofloxacin hydrochloride gastro-retentive tablets. METHODS: Hydroxypropyl methyl cellulose (HPMC), hydroxyethylcellulose (HEC) and hydroxypropylcellulose (HPC) were used as hydrophilic swelling excipients, and disintegrants crospovidone (PVPP XL and PVPP XL-10) or croscarmellose sodium (CCS) were used as swelling agents to facilitate the swelling/floating and drug release. Initial floating time and floating duration were tested to evaluate buoyance, and drug dissolution was tested to evaluate the controlled release. RESULTS: Using HPMC K250 and PVPP XL as excipients for ciprofloxacin hydrochloride gastro-retentive tablets could obtain products with rapid onset of floating, long floating durion and desirable drug release. CONCLUSION: Variety and amount of polymers have dramatic effects on buoyance and drug release of gastro-retentive tablets. HPMC K250 and PVPP XL are suitable excipients for ciprofloxacin hydrochloride gastro-retentive tablets.
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<p><b>OBJECTIVE</b>To set up the fittest medium and optimum condition for leaves from Rehmannia glutinosa to form regenerated plantlets directly and to induce microtubers.</p><p><b>METHOD</b>Leaves of different phases obtained from the virus-free plantlets were incubated in some kinds of media on the back side.</p><p><b>RESULT AND CONCLUSION</b>The fittest medium for the formation of regenerated plantlet was MS + 6-BA 2.0 mg.L-1 and the fittest medium for the induction of microtuber was MS + 6-BA 1.0 mg.L-1 + NAA 0.5 mg.L-1. The optimum incubation temperaue was 25 degrees C and the light length was (2,000-3,000 lx) 12 h.d-1.</p>