Endotoxins are poisonous substances that are produced in bacteria, and continue to exist after the bacteria has been destroyed. Therefore, a sterile surface may still retain dangerous endotoxins.
21CFR Part 211.94 states: “Drug product containers and closures shall be clean and, where indicated by the nature of the drug, sterilized and processed to remove pyrogenic properties to assure that they are suitable for their intended use.”
Depyrogenation and sterilization processes are used to eliminate viable matter and reduce the amount of endotoxin on vials or other containers used in pharmaceutical processing and distribution. These processes utilize dry heat at a prescribed temperature and duration. It is up to the pharmaceutical manufacturer to decide what cleaning, sterilization, and depyrogenation is appropriate for their given process.
The air used in the depyrogenation process must be filtered by leak free HEPA grade air filters.
Depyrogenation tunnels and continuous ovens are continuous systems that are used to reduce the amount of endotoxin to an acceptable level on glass or metal vials or other process containers and accessories.
Depyrogenation ovens are batch systems used to reduce the amount of endotoxin to an acceptable level on glass or metal vials or other process containers and accessories.
The items being subjected to the depyrogenation process must remain at the specified temperature for the specified time period for the process to be successful. Reduced heat-up and cool down periods as well as increased maximum temperature can increase the total throughput of the equipment.
In the past, the duration of batch depyrogenation processes has been determined by the ability of the HEPA filters to maintain the cleanliness class required (normally Class 100). Failure of the HEPA filters was a likely event during the heat-up and cool-down cycles. More recently, advances in HEPA filter technology have helped to reduce the negative impact HEPA filters have on the duration of the process.
Camfil Farr's Termikfil is an example of a new high-temperature HEPA filtration technology. Specifically designed for use in depyrogenation ovens and tunnels for sterilization purposes, Camfil Farr’s Termikfil is the only HEPA filter guaranteed to operate for a minimum of one year at a temperature of 350°C (662°F) while maintaining the leak-free integrity required to pass FDA validations.
The Termikfil frame is manufactured from ceramic based materials. The frame sealing method, using an element constructed of an exclusive polymineral material, provides leak-free performance when properly mounted to filter sealing surfaces. A unique, high-temperature, microfine glass media ensures consistent filter performance throughout the life of the filter. A stainless steel face grid is installed on both the air entering and air exiting sides of the filter to ensure protection of the media pack and add to the filter pack’s structural integrity. The Termikfil is pretreated, and pre-qualified, during the manufacturing process, with an exclusive heat preparation cycle (572º F, 300º C).
New high-temperature air filtration technologies have allowed equipment manufacturers to focus on other process related issues, maximize equipment performance, and reduce the cost of equipment operation.
Visit the High Temperature Filters section for more information about Camfil Farr high temperature products.