Sterile fluids steam sterilization

Great care is needed in the design of autoclaves and sterilization cycles because of the requirement for the presence of moisture. The autoclave must be loaded to allow complete steam penetration to occur in all parts of the load before timing of the sterilization cycle commences. The time required for complete penetration, the so-called heat-up time, varies with different autoclave constmction and different types of loads and packaging materials. The time may not exceed specific limits in order to guarantee reproducibility and, for porous loads, saturated steam. The volume of each container has a considerable effect on the heatup time whenever fluids are sterilized. Thermocouples led into the chamber through a special connector are often employed to determine heatup times and peak temperatures. The pressure is refleved at the end of each sterilization cycle. Either vented containers must be used or... 

British Standards Institution (1991) Specification for Steam Sterilizers for Aqueous Fluids in Rigid Sealed Containers BS 3970. London BSI. 

Industrial fermentors, as well as pipings, pipe fittings, and valves, and all parts that come into contact with the culture media and sterilized air are usually constructed from stainless steel. All ofthe inside surfaces should be smooth and easily polished in order to help maintain aseptic conditions. All fermentors (other than the glass type) must incorporate glass windows for visual observation. Naturally, all fermentors should have a variety of fluid inlets and outlets, as well as ports for sampling and instrument insertion. Live steam is often used to sterilize the inside surfaces of the fermentor, pipings, fittings, and valves. 

Blow-fill technology is an aseptic process whereby the container is formed from thermoplastic granules, filled with sterile solution and sealed, all within one automatic operation. The bulk solution should have a low bioburden and is delivered to the machine through a filling system that has been previously sanitized and steam sterilized in situ. Concern has been expressed that the machine itself may generate particles. The plastic granules are composed usually of polyethylene, polypropylene or one of their copolymers and are heat extruded at 200°C into a tube. The two halves of a mould close around this tube and seal the base. The required quantity of sterile fluid is filled into the container, which is then sealed. Products packed in this way include intravenous solutions, and small volume parenteral, ophthalmic and nebulizer solutions. The... 

Chemical Decontamination. Standardized procedures for chemical "sterilization" are generally set forth in manufacturer s instructions, but such procedures are of limited value when used in contact with concentrated biological fluids. These procedures, used with new and clean components, will give a percentage of sterile runs, but overall are laborious and moderately expensive in quantity of materials and time required. The present Millipore Minitan system incorporated steam sterilizable hardware, but the filter packets themselves cannot withstand steam sterilization. 

Mixtures of steam with air may be used for sterilizing sealed containers of aqueous fluids provided that steps are taken to ensure homogeneity of the steam-air mixture throughout the chamber, and the process has been validated. 

Good resistance to steam, pressurized hot water, ethylene oxide, and even gamma radiation makes SPS a good choice for applications that require sterilization. Favorable biocompatibility ratings (as measured by ISO 10993 testing) emphasize the capability to utilize SPS compounds for non-fluid/tissue contact medical devices. 

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