Clarification of fermentation broth and culture broth, sterilization of biological products, etc., and used it as a key quality control point in biopharmaceutical work. In addition, filtration technology has also been widely used in the pharmaceutical production process. This article briefly analyzes the application of deep filtration technology in biopharmaceutical processes, hoping to get some valuable opinions.

　　1 Surface filtration and depth filtration are usually divided into two types of filtration technologies, surface filtration and deep filtration. This division is based on different mechanisms. Currently, in the biopharmaceutical industry, these two types of filtration have been widely used.

　　Surface filtration: Surface filtration is to achieve the filtering function by capturing particles on the surface of the filter material, so it is necessary to uniformly arrange the pore size of the upper and lower filter materials. Among them, filters, membranes, etc. are very representative surface filters. Combined with the theory of surface filtration, we can know that when the filter medium intercepts solid particles in the fluid, it mainly depends on the size of the pore size, so that the surface of the filter material will stay and accumulate some suspended impurity particles in the liquid.

In-depth filtration: Generally speaking, the filter material is composed of fibers. The channels formed by the gaps of the filter media are often very tortuous and slender. The gaps in the media are larger than the impurity particles to be filtered, so that the filter media will be deep in the longitudinal direction. Catch particles. It should be understood that the filtering effect does not occur on the outer surface of the medium, but occurs in all the voids of the medium. Under the action of thermal motion and fluid dynamics, some small impurity particles in the liquid will flow on the channel wall, and electrostatic adsorption and surface tension will trap these impurity particles. In recent years, with the continuous development of membrane technology, many companies and research institutions have developed high-performance filter membranes, which have strong deep filtration performance.

2 The development history of deep filtration technology and filter materials In the biopharmaceutical process, companies have very high requirements for the accuracy of filter media. In order to improve the accuracy of filter products, filter product suppliers often use The way is to increase the density of the filter material. However, there are some drawbacks in using this method. If the filter medium has a higher density, during the filtration process, the filter medium will have a larger pressure difference and reduce the flow rate, so the filtration performance will be affected. With high strength, some other phenomena, such as the breakdown of the filter material, will occur, so that the quality of the downstream fluid cannot be guaranteed.

　　 In the 1970s, the United States made clear regulations on filter media that asbestos materials should not be used, because asbestos materials have carcinogenic substances. Later, a scientist invented the ZETAPLUS filter material. This filter material does not use asbestos material, but has a stronger positive charge than asbestos, so that the pressure difference and flow rate problems in precision filtration can be well resolved. ZETAPLUS filter material is made from a mixture of two materials, namely filter aid and wood fiber matrix. In the production process, using chemical functional groups, the polymer resin can be connected to the basic components. This polymer resin is charged, which will form a stable chemical connection, so that the filter material can be electrostatically trapped. Charge.

　　3 Application of depth filter media in the field of biopharmaceuticals. In the process liquid of biopharmaceuticals, negative charges exist in many media, such as cells and cell debris, contaminated DNA, endotoxins, and so on. Under normal circumstances, the working principle of deep filtration can be divided into two parts, one is mechanical filtration, the other is electrostatic adsorption, through mechanical filtration, those particles larger than the pore size can be directly filtered. If the particles are smaller than the pore size, the Under low pH conditions, it will be negatively charged, which will adsorb on the resin because the resin has a positive charge. The use of a deep filter material with a positive potential can achieve the purpose of improving filtration efficiency.

Clarification of the fermentation broth: After the fermentation is over, after the crude liquid is separated, some other components will still be mixed in the supernatant, such as a small amount of cells, colloidal substances, cell debris, etc., these components are all negatively charged . If you use the ZETAPLUSS system's deep filtration products, these active ingredients can be refined step by step, which can organically combine mechanical interception and electrostatic adsorption. Practice has shown that this method has only a small pressure drop and a higher flux. The efficiency can be greatly improved, the operation process can also be simplified, and the downstream purification equipment can be protected.

　　 In addition to pyrogens: Pyrogens are what we commonly call endotoxins, which are cell debris, which are produced on the outer wall of Gram-negative bacteria. It is a lipopolysaccharide substance because it is produced by different bacterial species and has a molecular weight of millions. You know, the body will be greatly harmed by pyrogens. Under normal circumstances, the repeated adsorption of activated carbon is used to remove the pyrogen in the preparation. This method does not have a very good effect. At the same time, it requires greater labor intensity and greater loss. The use of ZETAPLUSP can effectively solve these problems. This product organically combines electrostatic adsorption and mechanical interception methods, which not only has a higher product yield, but also has better product quality, and does not require too much Labor intensity.