Application of microwave vacuum equipment in pharmaceutical industry

Microwave extraction, namely microwave assisted extraction (MAE), according to the different absorption capacity of different substances, some areas of the matrix material or some components of the extraction system are selected to be heated. The extracted materials are separated from the substrate or system, with small dielectric constant and relatively poor microwave absorption capacity

1. Mechanism of microwave extraction. Microwave is an electromagnetic wave with frequency between 300MHz and 300GHZ, which has four basic characteristics: volatility, high frequency, thermal and non thermal characteristics. The microwave frequency is 2450MHz. Microwave heating is a kind of rapid rotation and direction arrangement of polar molecules (H2O, CH2Cl2, etc.) of heating materials in microwave electromagnetic field, which results in tearing and friction heating. The heat transfer formula of traditional heating method is heat source, vessel and sample, so the efficiency of heat transfer is limited. Microwave heating is directly used for heating materials, and its mode is heat source → sample → utensils. The air and the container basically do not absorb and reflect the microwave, which fundamentally ensures the rapid transmission and full use of energy The characteristics of microwave extraction. ① It is reflected in the selectivity of microwave, because of the selective heating of polar molecules, the selectivity is dissolved. ② Mae greatly reduces the extraction time and improves the extraction speed. The traditional method takes several hours to ten hours, and the ultrasonic extraction method also takes half an hour to an hour. Microwave extraction only takes a few seconds to minutes, and the extraction speed is increased by several tens to hundreds or even thousands times. ③ Microwave extraction is limited by the affinity of solvent, and more solvents can be selected, and the use of solvent is reduced. In addition, microwave extraction is used for large-scale production, safe and reliable, pollution-free, belongs to green engineering, and the production line is simple and can save investment. Microwave extraction is generally suitable for thermal stability substances. For heat sensitive materials, microwave heating materials which are easy to denaturate or inactivate require good water absorption. Otherwise, it is difficult for cells to absorb enough microwave to destroy themselves, and the microwave extraction of production and release has poor selectivity for the components . application of microwave extraction. Microwave extraction is widely used in the extraction of glycosides, flavonoids, posts, polysaccharides, alkaloids and other components. ① Alkaloids. Ganzler The content of spartine in microwave extract is 20% higher than that of vibration method, and the speed is fast and the solvent consumption is also greatly reduced The parameters of solvent, particle size, humidity, microwave power and irradiation time were studied. The extract is equivalent to the traditional method, but it takes only 30 seconds. Some scholars have studied the influence of microwave technology on Ephedrine Extraction in ephedra, compared the inferior of microwave extraction and conventional decocting. After all, microwave method has obvious amount of Ephedrine Extraction than decoction, and half of the crude ephedrine extract is obviously in the total amount of ephedrine pieces, which is in line with the traditional Chinese medicine theory of boiling powder. The results of the measurement of dry solid and chorionic promotor were used to compare microwave and reflux. According to the results of the determination of dry solid, the content of velvet with obvious potential in microwave treatment is the index in unit time than that of reflux extraction, and the content of velvet extracted by reflux is higher than that of microwave extraction. ② Address class. Deng Shouzhu and others studied the influence of microwave technology on the extraction of phenol from rhubarb. The effects of microwave output power, material size and leaching time on the extraction rate were investigated by orthogonal experiment. According to the microwave immersion scheme and the usual decocting method and ethanol reflux method, the results showed that the material particle size had a great influence on the extraction of benzene, and the electric power had a significant influence on the leaching, and the time had a certain influence on the leaching. The extraction rate of free mites by microwave is obviously higher than that of the traditional decocting method, which is equivalent to the ethanol reflux method. Shen Lan and others used the phenol components of different polar locations in rhubarb and cassia as the index components. The results showed that microwave extraction method had no obvious selectivity for the extraction of different polar components in rhubarb and cassia. However, under the same temperature, flavin, chrysophanol, xanthopherol, and chrysophanol were selected from rhubarb and Cassia by microwave extraction The extraction rate of emodin methyl ether was significantly higher than that of Semen Cassia seed. ③ Flavonoids. Liu Chuanbin and others combined microwave cell breaking with solvent extraction to extract salidroside from Rhodiola Alpinia callus. The results show that the preparation of Rhodioloside can be fully brewed out after microwave treatment for 1 minute, and the water can be bubbled for 10 minutes at room temperature. Compared with the traditional method, the former has short time, no need to be heated and the impurities in the solution are less. The flavonoid components in Ginkgo leaves were also extracted by this method. After 5 minutes microwave treatment, 70% ethanol was used to reflux for 1 hour. The content of flavonoids in the extract was 18.8% higher than that of the non microwave treatment. The paper layer analysis showed that the properties of flavonoids would not change under the microwave temperature. Li Shenghe and others also studied the extraction technology of ginkgo flavonoid glycosides by this method, and got ideal results. In addition, yanshuxiao and others extracted antioxidant substances from ginger. The results showed that the extraction rate of flavonoids was significantly increased after microwave treatment for 5 minutes. Guo zhenku et al. Studied the microwave extraction of baicalin. In orthogonal design, the best technology is 70% microwave power (high power 850 watts), 35% ethanol as solvent, 30 times solvent, 0.15Mpa pressure, 30 seconds constant pressure zhangmengjun, etc. the best conditions for extracting flavonoids from Glycyrrhiza by micro wave are solid-liquid ratio of 1/8, ethanol concentration of 78%, microwave power of 388 watts, The extraction time is 1 minute. The extraction rate of microwave method (24.6mg/ml) was significantly higher than that of water extraction (11.4mg/ml). Chen Bin et al. Studied the microwave extraction technology of isoflavonoid from Pueraria Puerariae. 77% ethanol was used, the solid-liquid ratio was 1/14, under the condition of 60 ℃, the microwave intermittent treatment was carried out for three times, and the total flavonoid extraction rate reached more than 95%. Compared with the traditional thermal extraction, the total flavonoid was not only high productivity, but also fast and energy saving. The results showed that the extraction efficiency was improved, the extraction time was shortened and the score rate of the effective components was significantly improved. ④ Soap glycosides. According to the study, the microwave method was used to extract saponins from the plant. Results the microwave treatment for 5 minutes basically reached the normal heating effect of 2 hours. The extraction of saponins was considered to be finished after 10 minutes microwave extraction. ⑤ Organic acids. Guo zhenku and other special microwave sample preparation systems with high pressure control precision designed by himself have investigated the extraction conditions of chlorogenic acid and isochlorogenic acid compounds in honeysuckle. Compared with ultrasonic extraction, the extraction rate is nearly 20% higher than that of ultrasonic. The results of microwave bubbling of glycyrrhizic acid in Guo Jintang and other applications can be obtained in 8 minutes, which is equivalent to the continuous reflux bubbling for 3 hours. Microwave vacuum drying equipment

Microwave vacuum drying equipment ⑥ Polysaccharides. The staff of the school of medicine of Shihezi University of Xinjiang have done a lot of work in the microwave extraction of polysaccharides. The plants extracted include licorice, commercial land, Cistanche, rhodiola root, Rhodiola leaves, astragalus, and dangshen. In mcl-3 microwave reactor, they were reflux with a certain amount of petroleum ether, ether and 80% ethanol for 20 minutes. The residue was put into microwave again. After 20 minutes of water extraction, the polysaccharide content was measured. The extraction rate was higher than that of traditional method, and the extraction time was shortened by about 12 times. Tangkehua et al. Obtained the polysaccharide by microwave, and confirmed that microwave extraction of fructose in 80 ℃ alkaline medium combined with microwave pretreatment can obtain a high extraction rate. Liu Yi et al. Treated the root by microwave, then decocted the polysaccharide with water. The content of the polysaccharide showed that the yield of crude polysaccharide was 33.062%, the mass fraction was 75.211%, and the method was decocted by water alone. Some people use microwave to extract tea polysaccharides, and the score rate of tea polysaccharides is 2.52%. UV and IR linear analysis show that the technology has no effect on the chemical structure of tea polysaccharide products. In addition, the score rate of the oligosaccharides extracted by microwave method was significantly higher than that of non microwave conditions, and the dissolution time was shortened significantly, only 6 minutes. ⑦ Volatile oil. At present, many overseas scholars have begun to use microwave to extract volatile oil. Pare, Canadian environmental agency, applied for a U.S. patent in 1991. The natural products include mint, celery, cedar leaves and garlic, etc. and are microwave transparent (self alkanes, etc.) or partially transparent (methanol, dichloromethane, etc.) solvents. The extraction process and requirements mentioned in the patent are: (1) the material is crushed, and the extracted components can absorb microwave radiation ② the material is put into the microwave transparent or partially transparent extractant ③ the microwave radiation of a certain frequency is used to extract ④ the extract ⑤ is recovered or directly used (if it is not necessary to separate).