The production of pharmaceutical products are subject to high quality demands. The applications listed
below operate under vacuum for separation without thermally degrading the products, and the inlet pressures vary by the process, anywhere from 0.01 Torr to 50 Torr.
Degassing is the removal of dissolved gases in liquid or solid products. Vacuum pumps are used for extraction of the unwanted gases from the product.
Distillation is the thermal process to separate different solvents from a liquid mixture. Each solvent differs in temperature, pressure and composition. To separate different solvents from each other, the vapor has to be removed from a boiling liquid mixture and recondensed after the evaporation. Vacuum pumps are used for removal of non-condensable, water and light solvents.
This is an evaporation and cooling process of supersaturated liquid to form crystals. Vacuum pumps are used to control the evaporation and cooling rates at various pressure ranges.
Drying is an operation to separate liquids from solids. The moisture has to be evaporated by introducing heat into the wet products. In order to prevent heat sensitive media from being thermally degraded, vacuum drying is used to maintain low temperatures.
FREEZE DRYING (A.K.A LYOPHILIZATION OR SUBLIMATION)
Sublimation is a process whereby a solid is transformed to a gas phase without going through the liquid phase. This allows for the removal of excess material without creating a degraded condition for the end products.
Freezing of the starting dilute solution to sub ambient temperatures induces solidification, first of the solvent, followed by solidification of the remaining solutes from a more highly concentrated composition. An environment of reduced pressure while the product is maintained at sub ambient temperature promotes sublimation, converting the ice directly to water vapor, avoiding the return of the composition to the liquid state. This allows drying while retaining the attributes of the frozen preparation.
Sterilization is a process designed to remove or destroy all viable forms of microbial life, including bacterial spores. Widely used methods are Steam and Ethylene Oxide (ETO) sterilization. A vacuum pump is used to evacuate the sterilization chamber and handles the inert gases like Nitrogen and flammable gas ethylene oxide.
In the pharmaceutical industry, vacuum pumps come into contact with solvents, vapors and various gases. Therefore, end users are seeking a vacuum pump with reliable performance and durability. Custom vacuum design for this industry should consider the following:
1) Material of construction of the vacuum pump and system
2) Process compatible solvents for sealing medium for liquid ring pumps
3) Staging vacuum systems that consist of booster/air ejector/roughing pump
4) Dry vacuum pump with flushing and purging options
5) System design with knock out pot, Pre condensers & Post condensers
6) Explosion-proof electrical
7) Automation and controls
Tuthill Vacuum & Blower Systems provides comprehensive engineering solutions and products solutions to cover the wide spectrum of inlet pressures and suction capacity for the chemical and pharmaceutical markets.
Steam Sterilization uses high temperature steam to destroy all living organisms. The Steam Sterilization Process consists of loading products within the chamber or autoclave, evacuation of the atmospheric air down to a pressure of approximately 1.5-2" Hg A, and multiple steam cycles where the autoclave is backfilled with steam to elevated pressures and temperatures and then re-evacuated and backfilled to insure contact and sterilization, a drying cycle to remove all steam, and then proper bleed up to atmosphere, and product removal. The effectiveness of the sterilization process relies upon the repeatability of the evacuation/pressure pulsation process to remove air and insure steam penetrates the product. The vacuum system must be able to perform effectively and reliably pumping down the autoclave whether containing air or steam.
The typical vacuum pump used is a water-sealed Liquid Ring Vacuum Pump with or without an inlet condenser. Tuthill Vacuum & Blower Systems has been designing and manufacturing such systems for decades and can offer a pumping package to provide what the customer prefers to meet rigorous pumpdown times for air and/or steam evacuation while handling the process gases and vapor heat loads. Full sealant recovery systems are used to minimize waste water, but once-through or partial-sealant recovery systems can be provided if preferred.
The Ethylene Oxide (EtO) Sterilization Process is preferred for sterilizing temperature or moisture sensitive products. It uses Ethylene Oxide gas which is toxic, flammable, and carcinogenic to chemically attack, through an alkylation reaction, the DNA of the microorganisms. The Ethylene Oxide Sterilization Process normally requires that the products be preconditioned in a controlled environment of temperature and humidity whether outside or inside the chamber. The autoclave or chamber is then evacuated to approximately 1.5-2" Hg A. In some cases evacuation of the air is followed by inert gas (normally Nitrogen) injections and re-evacuations to insure air removal through dilution. A leakup test may also be performed to check chamber leak integrity before introduction of the EtO. Temperature and humidity are controlled depending upon the products being sterilized with maximum temperatures normally less than 60°C. The gaseous phase EtO is injected into the chamber. Again, the EtO concentration and exposure time depends upon the product and ease of penetration and sterilization balanced against ease of cleanup of residual EtO. The EtO is then removed through successive evacuation and aeration processes.
The typical vacuum system used is a water-sealed Liquid Ring Vacuum Pump. Because EtO is completely miscible with water, it can dissolve in the sealant water during discharge and outgas during exposure to the pump suction reducing the net pumping capacity at lower pressures. In some cases a Booster/Liquid Ring may be used to enhance the low pressure pumping capacity, or a Dry Pump may be used which avoids contact with a liquid.