Application Of Supercritical Fluid To Traditional Chinese Medicine Of T.Wilfordii And The Study On Solubility

Supercritical fluid extraction (SFE) is one of the key technologies used in modernization of traditional Chinese medicine. It is environment friendly and efficient energy saving. Tripterygium Wilfordii Hook.f. (T.Wilfordii) is a kind of traditional Chinese medicine, which has immunosuppressive effect. The extracts derived from traditional methods have severe toxic and side effects and the content of the main active component in the extracts is very low. So in this article, the SFE was applied in the extraction and analysis of the active components in T.Wilfordii. Meanwhile, the new dosage form of the extract of T.Wilfordii was also investigated. These researches can improve the efficacy of the medicine and promote the modernization and internationalization of traditional Chinese medicine industry. The theoretical research on the solubility in supercritical fluid was also done. This theoretical research has the guiding role for the process design of SFE.The supercritical carbon dioxide (SC-CO₂) modified with static co-solvent extraction was used to extract the active components from T.Wilfordii. Taking the yield and content of triptolide, total alkaloids and tripterine as quality indexes, Some influence factors such as co-solvent variety and its composition, the extraction temperature, pressure and the static soak time were studied. The experimental results show that when 75% ethanol as co-solvent is used for 3 h of static soak time under the extraction temperature of 43℃and pressure of 25 MPa, the yield of the main active component triptolide is 3.49 times as much as that of the traditional method of 95% ethanol reflux extraction-chloroform extraction. The results of chromatographic fingerprint of the SFE extract show that the extraction by the SC-CO₂ modified with static co-solvent is stable and the similarity of ten batches of SFE extracts is between 0.95 and 1.00. The results of pharmacological experiments in vivo and in vitro show that the efficacy of SFE extract is 3⁴ times as much as that of the drugs while the toxicity of SFE extract is only one half of that of the drugs on sale.Based on the above extraction results, triptolide in the plant was further extracted with SC-CO₂ combined with high-pressure solvent. The effect of variety of co-solvents, adding modes and usage, extraction temperature and pressure were investigated. The results show that, the yield of triptolide is 1.25 times higher than that of SC-CO₂ modified with static co-solvent extraction when the operation parameters are as follow: the ratio of 85% ethanol solution added to the raw material is 1 mL/g in the presoak stage, the flow rate of SC-CO₂ is 1.5 L/min, the flow rate of co-solvent of 85% ethanol, 1 mL/min, the extraction temperature, 50℃, extraction pressure,25 MPa, 15 min of presoak, and 30 min of extraction time. As this process needs a large amount of solvent, its feasibility should be investigated further.In order to reduce the toxicity of the SFE extract of T.Wilfordii, the complicated extracts were entrapped into liposomes by thin film-dispersion method. The effects of process parameters and composition of prescription on the entrapment efficiency of tripterine and total alkaloids were studied. The results showed that the entrapment efficiency of tripterine and the total alkaloids are respectively 98.10% and 88.63% under the optimum conditions.The SC-CO₂ modified with static co-solvent extraction was also used as pretreatment method in the determination of tripterine in T.Wilfordii. The pretreatment process was optimized by investigating the effects of co-solvent variety, extraction temperature, extraction pressure, extraction times and usage of co-solvent on the yield of tripterine. This method reduced the consumption of the organic solvent and time. Recovery of tripterine for SFE varies from 90.5% to 103.2% for samples with different content levels. The limit of detection and quantification are 2.2μg/mL and 7.36μg/mL. All the other indexes also satisfy the analytical requirements.Finally, the solubility of fatty acids, fatty alcohols, fatty esters and triglycerides in SC-CO₂ was studied. In this research, the linear relationship between the parameters in Chrastil's equation and the solutes'molecular connectivity indices (MCIs) was built. So the solutes'solubility can be estimated only by their MCIs. This method is proved to be simple and can estimate the solubility in the order of magnitude.