RESUMO
Objective:To compare the volatile constituents in mugwort leaves produced in Qichun, Hubei Province and Nanyang, Henan Province. Methods:The volatile constituents were extracted using headspace heating and analyzed using gas chromatography-mass spectrometry (GC-MS). Then a qualitative analysis was made according to the standard database provided by the National Institute of Standards and Technology (NIST) and the relative contents of each constituent were calculated using the peak area normalization method. Results:A total of 59 compounds were identified from the mugwort leaves from Qichun and 51 compounds were identified from the mugwort leaves from Nanyang. These mainly include monoterpenoids, sesquiterpenoids, CxHyOz and other compounds involving the aldehyde, ketone, alkane and benzene. The mugwort leaves from Qichun and Nanyang share 32 common volatile constituents. The chromatographic peak area of identified compounds accounting for 96.38% of GC-MS total chromatographic peak areain Qichun mugwort leaves, versus 95.54% of that in Nanyang mugwort leaves. Conclusion:The headspace heating extraction combined with GC-MS technology can evidently display similarities and differences of volatile constituents in mugwort leaves produced in different areas and thus provide scientific basis for the quality and screening of mugwort leaves.
RESUMO
The aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. A water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan [CMCTS], decylalkyl dimethyl ammonium and epichlorohydrin. The elemental analysis showed that the target product with 10.27% of the maximum grafting degree was obtained. To assess the preliminary safety of this biopolymer, cell toxicity assay was employed. In order to further investigate quaternary ammonium carboxymethylchitosan application as pharmaceutical excipient, aspirin was chosen as model drug. The effect of quaternary ammonium CMCTS on aspirin release rate from sustained-release matrix tablets was examined by in-vitrodissolution experiments. The results showed that this biopolymer had a great potential in increasing the dissolution of poorly soluble drug. With the addition of CMCTS-CEDA, the final cumulative release rate of drug rose up to 90%. After 12 h, at the grade of 10, 20 and 50 cps, the drug release rate increased from 58.1 to 90.7%, from 64.1 to 93.9%, from 69.3 to 96.1%, respectively. At the same time, aspirin release rate from sustained-release model was found to be related to the amount of quaternary ammonium CMCTS employed. With the increase of CMCTS-CEDA content, the accumulated release rate increased from 69.1% to 86.7%. The mechanism of aspirin release from sustained-release matrix tablets was also preliminary studied to be Fick diffusion. These data demonstrated that the chitosan derivative has positive effect on drug release from sustained-release matrix tablets