Separation Of Phosphatidylcholine Extract And Usnic Acid Liposomes

There are two parts in this paper. The part one, untreated egg phospholipids as starting material was separated to gain E80 and the deep product E98, and the qualities of two products were evaluated. The quality parameters of E80 include acid value, iodine value, saponification value, the related substance, the water content, etc. Except for the options of quality parameters of E80, the ¹HNMR and ¹³HNMR was used to detemine the structure of PC. High-performance liquid chromatoguaphic (HPLC) was used to analyse the varieties of phospholipids and contents in two products. The part two, the fit ratio of E98 and cholesterol was choosed to prepare liposomal usnic acid. The liposomes' qualities were evaluated such as particle size, durg-to-lipid ratio, durg-carrying, encapsulated efficiency, etc. The stability of the liposomes was also measured after one month.The method of precipitation with organic solvent was used to gain E80. First, the raw material was dissolved and marinated by acetone and ethanol without water in turn, and precipitated with vaporized acetone to gain raw product, then the raw product was decolorized with activated carbon, and refined with 95% ethanol. Finally, product was obtained by secondary deposited with vaporized acetone, and freeze dried. According to the Chinese Pharmacopeia which published in the year of 2005, the quality parameters of E80 were evaluated. The results show that the method which mentioned above could procure valid product. The quality parameters are consistent with the standard of Baoji Libang Bioengineering CO. LTD. Comparison with the lipid E80 made in Germany, our product has same content. This showed that our product could repalce the lipoid E80 in our life.The further product E98 was prepared by means of column chromatography using E80 as raw material, and the eluant was the mixture of chloroform and methanol. The eluant solution was detected by TLC in real time. According as the result of TLC, the ratio of chloroform and methanol was changed. The eluant solution was collected in batches and concentrated, decolorized, then deposited and freeze dried. The quality parameters of E98 were evaluated using the method of E80. The result showed that the purity of the product was above 98%. The structure of PC was determined by means of ¹HNMR and ¹³CNMR.Using E98 and cholesterol as raw material, the liposomal usnic acid was prepared. And the quality parameter was alsoevaluated. The condition of HPLC and the detecting method to the encapsulate efficiency were established. A 250mm×4.6mm C₁₈ (5μ) colomn with a mobile phase consisting of methanol-phosphate buffer solution (pH about 5.0) = 70:30 (v:v) was used. Chromatography was performed at ambient temperature with flow-rate of lml/min and ultravioilet detection at 284nm. The mini-gel column made with Sephadex G-25 polyglucosan gel was used to separate liposomes and free drug, and using the vaporized water as eluant. The content of drug in liposomes was detected by HPLC. According to the data, the encapsulation efficiency was calculated. The result showed that the liposome could encapsulate drug 1mg/ml, the particle size was 130±20nm, the encapsulation efficiency was above 90%, and the drug-carring was about 1mg/50mg.It was found that the particle size of liposomal usnic acid deposited one month was a little bigger than before, which consisted with some documents said that it was concerned with the neutral phospholipids of PC. The encapsulate efficiency was lower also.