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Based on the basic requirements for the use of centrifuges in the pharmaceutical industry as well as GMP requirements, design specifications are established to ensure the reliability, reproducibility, consistency, and safety of centrifuges during production processes (when processing specific products). 1. Model selection: Choosing the appropriate model is crucial for meeting GMP requirements. For certain specific products and locations, some models are not suitable; even with significant efforts in terms of design, it may not be possible to achieve the desired results. Users of centrifuges should submit a specification document URS outlining their requirements for such centrifuges; that is, they should specify the exact needs based on the actual working conditions, the physical and chemical properties of the materials to be processed, the processing requirements, and control aspects, so as to determine the appropriate model together with the manufacturer. 2. Material selection: The specifications require that the surfaces of equipment in direct contact with drugs do not undergo chemical reactions with the drugs or absorb them. Therefore, for a specific medium, appropriate materials should be selected for manufacturing in order to meet the aforementioned requirements, as well as to fulfill the basic requirement of corrosion resistance. These materials are not limited to metal materials such as drums; all components that come into contact with the material must meet this requirement, including seals, fasteners, and so on. The selection of materials is crucial for achieving corrosion resistance and meeting cleanliness requirements; appropriate materials are chosen based on the corrosion data of the materials to be separated (chemical properties, temperature, concentration, etc.). For piping used in applications with high cleanliness requirements, sanitary-grade pipes and sanitary-grade quick-install fittings should be selected to eliminate potential contamination from the pipes and to facilitate cleaning. 3. Structural design and surface treatment: During design, joint surfaces should be reduced as much as possible (or eliminated) in order to avoid dirt accumulation in the gaps between these surfaces, which makes cleaning difficult. The weld joints should be continuous (without any interruptions in welding); fillet welds should be ground to form smooth, rounded corners, while butt welds should be smoothed out. All sharp edges and corners must be rounded to create smooth transitions; protrusions and depressions should be eliminated as much as possible, in order to remove areas that are difficult to clean and spots where liquid or debris can accumulate. All stainless steel surfaces should be polished in order to minimize the adhesion of contaminants to the surface of the equipment and improve cleaning efficiency. During the maintenance of the centrifuge, maintenance personnel, tools, spare parts, and other items can all cause contamination in the sterile workshop. Therefore, the design of the centrifuge should feature a simple structure, ease of disassembly, and convenience in transportation, to ensure the rationality and reliability of its design. 4. Online cleaning: To ensure consistency in each batch of products and prevent contamination due to the product’s own structure as well as microorganisms and pathogens, cleaning, disinfection, and sterilization systems should be incorporated into the design (using solutions acceptable to the user). All surfaces need to be easy to clean, and it must be ensured that contamination or chemical reactions cannot occur during the production process. Multiple cleaning heads or tubes are installed in the interior of the centrifuge (at multiple locations), allowing the centrifuge to clean its internal, invisible surfaces without having to open the cover or while it is in operation. 5. Airtightness: Pharmaceutical centrifuges, whether used for non-sterile or sterile drugs, as well as for drug intermediates or finished drugs, require high standards with regard to the environment during their production process. Under high-level environmental requirements, such as in sterile workshops, there are sterile areas classified as Class C, Class D, etc.; good airtightness enables effective isolation between the outside environment and the interior of the machinery. The solid, liquid, and gas phases within the centrifuge’s interior must not cause pollution to the workshop environment ； Conversely, operators and the external environment must also not contaminate the materials. Therefore, pharmaceutical manufacturers should inform the centrifuge manufacturer of their sealing requirements when placing orders. 6. Meeting explosion-proof requirements: In applications involving organic solvents such as methanol, ethanol, and toluene, the production system must meet explosion-proof standards; therefore, the safety of the centrifuge during operation becomes a key consideration in its selection. There are many factors that contribute to an explosion: concentration of flammable gases, pressure, temperature, ignition sources, oxygen, etc. For specific media or applications, whether in the liquid or gas phase, factors such as the concentration of flammable gases, pressure, and temperature should be taken into account during process design. Due to it being a process-related issue, it will not be discussed here. Regarding fire sources, when designing a centrifuge, sufficient safety clearance must be provided for moving parts to eliminate any potential frictional contact and collisions. The machine must have measures to eliminate static electricity. For braking devices, energy-dissipating braking is generally used (a non-contact type of braking; its drawback is that the braking time is slightly longer than that of contact-type braking, especially when the moment of inertia is large under full load). Mechanical friction-based braking devices must not be used. For conveyor belts, anti-static belts should be used to eliminate or reduce the likelihood of static electricity generation. 7. Gas source: The pneumatic actuating components used in centrifuges, such as pneumatic scrapers, gas-assisted scrapers, and gas recoil devices, are powered by gas (compressed air or compressed nitrogen). The gas source must be purified to ensure that the pharmaceutical products are not contaminated by impurities present in the gas. If used in explosion-proof environments, nitrogen should be used as the gas source. 8. Removal of residual filter cake and regeneration of filter cloth: In top-discharge centrifuges (where manual top discharge or bag-lifting discharge is used), the filter bag is removed during each discharge process. Consequently, it is relatively easy to remove the residual filter cake, and the regeneration of the filter cloth is also more convenient. No further details will be provided here regarding this type of centrifuge. Instead, we will mainly describe the methods for removing residual filter cake and regenerating filter cloth in scraper-discharge centrifuges. Scraper discharge centrifuges (vertical scraper discharge centrifuges, horizontal scraper discharge centrifuges, etc.), being automatic types of centrifuges with filter cloths installed on the drum walls, are somewhat more difficult to disassemble and assemble compared to top-discharge centrifuges. There is a safety distance (5–10 mm) between the scraper and the filter cloth to prevent the scraper from damaging it. For ordinary chemical products, the presence of this residual filter cake layer does not pose a significant problem; however, in the pharmaceutical industry, such residual filter cake cannot meet the requirements for eliminating contamination between batches. To remove the residual filter cake, a gas-assisted scraper is installed on the scraper itself, and gas backflush nozzles are placed outside the filter holes of the drum. During scraping, high-pressure gas passes through these filter holes from the outside inward, impacting the filter cloth and the layer of residual filter cake; this causes the filter cloth to oscillate pulsatively and to move inward, thereby using a gentle pushing force to bring the filter cloth closer to the edge of the scraper and reducing the thickness of the residual filter cake layer. At the same time, the high-pressure gas emitted by the gas backflush nozzles blows away the residual filter cake from the filter cloth. This device can effectively reduce or eliminate residual filter cake, while also regenerating the filter cloth to a certain extent. The removal of residual filter cake helps to eliminate the filtering resistance caused by such residue during the next filtration process, thereby improving filtration efficiency for materials with smaller particle sizes or higher viscosity.