1. Extraction method
At present, the separation and purification methods of Oleanolic Acid Sigma commonly used in this field mainly include: organic solvent extraction method, precipitation method, column chromatography step elution method, macroporous adsorption resin method, high-speed countercurrent chromatography, etc. Microwave extraction is to use the difference in the ability of substances with different structures to absorb microwaves in the microwave field, so that some regions in the substance or some components in the extraction system are selectively heated, so that the extracted material is separated from the substance or system. , into the extractant with small dielectric constant and relatively poor microwave absorption ability. The advantages of this method are that it has high selectivity to the extract, high extraction rate, fast extraction speed, less solvent consumption, safety, energy saving, and simple equipment. Simulated moving bed chromatography technology is to introduce the design idea of simulated moving bed into liquid preparative chromatography, which not only maintains the advantages of low consumption, high separation purity, and variable temperature operation of liquid preparative chromatography, but also overcomes the usual liquid preparative chromatography. The disadvantage of not being able to operate continuously makes it have the characteristics of strong separation ability, small size of equipment, low investment cost, and it is especially beneficial to the separation of materials with high heat sensitivity and difficult separation.
CN201510083053.9 provides a method capable of effectively extracting and separating oleanolic acid in Prunella vulgaris. The method for extracting oleanolic acid from Prunella vulgaris of the present invention comprises the following steps:
(1) pulverize the dried Prunella vulgaris, pass through a 20-60 mesh sieve, place it in a microwave synthesis extractor for extraction, add ethanol solution to reflux for extraction; filter out the extract, concentrate under reduced pressure to recover the solvent to obtain extract A;
(2) adding petroleum ether to the extract A for leaching, then dissolving with an ethanol solution, filtering, and entering the filtrate into simulated moving bed chromatography for separation to obtain component B rich in Oleanolic Acid Sigma;
(3) The solvent is recovered and dried under reduced pressure to obtain oleanolic acid with a purity of more than 95%.
The Oleanolic Acid Sigma extraction method of the present invention adopts the technology of combining microwave-assisted extraction and simulated moving bed chromatography to separate and purify, and determines the relevant process parameters. The steps are simple, the product purity is high, the extraction and separation time is short, and the production efficiency is obtained. improve.
2. Preparation of oleanolic acid polyvesicular liposomes
At present, the related preparations of oleanolic acid in clinical practice are mainly Oleanolic Acid Sigma tablets, but oleanolic acid is a fat-soluble drug, which has the disadvantages of low dissolution rate in the gastrointestinal tract, poor absorption, and obvious first-pass effect in the liver, making it a Bioavailability is greatly reduced, therefore, research and development of new formulations of Oleanolic Acid Sigma is necessary. CN201510401465.2 provides an oleanolic acid multivesicular liposome with high bioavailability, a preparation method and application thereof. Include the following steps:
1), take by weighing soybean lecithin, cholesterol, glyceryl trioleate, oleanolic acid, stearic acid and be dissolved in organic solvent, dissolve and form oil phase;
2), add a specified amount of oil phase to the inner water phase, and shear and disperse with an emulsifying machine to form colostrum;
3), take the colostrum of the specified amount and join in the outer water phase, vortex oscillation forms double milk;
4), the double emulsion is rapidly transferred to a round-bottomed flask, and the organic solvent is removed by rotary evaporation to obtain oleanolic acid polyvesicular liposomes.
In the present invention, oleanolic acid is loaded in the lipid layer of multivesicular liposomes to prepare oleanolic acid multivesicular liposomes (OA-MVLs), in order to improve bioavailability, achieve slow release of drugs, and reduce the number of administrations , the purpose of improving patient compliance.