Sterilization vs. Pasteurization For Parenteral Products
What is sterilization?
Sterilization is any process that removes, kills, or deactivates all forms of life. Sterilization is related to the term sterile, which means a complete absence of viable microorganisms or microbes that have the potential to reproduce. Thus, sterile products that undergo sterilization are often chemically or heat sterilized after being placed in their final packaging. The chemical or heat sterilization kills any microorganisms inside the products (obtained during manufacturing and packaging). This chemical or heat sterilization process after final product packaging is known as terminal sterilization.
What is the difference between sterile and aseptic?
While both sterile and aseptic products will prevent microbial contamination following use, the processes by which microbial contamination is prevented are different. An aseptic process prevents contamination by the exclusion of microorganisms. In contrast, products created using a sterile process use a terminal sterilization process to kill live microbes before product use. Though the definitions for aseptic and sterile are not the same, sterile is used interchangeably with aseptic. Indeed, many products labeled as sterile are manufactured by aseptic processing rather than terminal sterilization.
What is pasteurization?
Pasteurization is a method named after its inventor, French chemist and biologist, Louis Pasteur. Pasteurization is a technique to kill pathogenic organisms (such as bacteria) without harming the flavor or quality of the product. Pasteurization is known for its use in milk. However, pasteurization is used for other products like beer, wine, fruit juices, and more! The traditional pasteurization method for milk involves heating the milk to 145°F (63°C) for 30 minutes or, heating it to 160°F (71°C) for 15 seconds, followed by rapid cooling to the temperature at which it is stored, below 50°F (10°C).
What is the difference between sterile and pasteurized for parenteral products?
The process of pasteurization is not robust enough to sterilize parenteral products or other medical products that bypass the body’s natural defense barriers (i.e., mouth, nose, skin, and anus). Thus, pasteurization cannot be used for sterile parenteral products.
Can parenteral products be pasteurized?
Some parenteral products use pasteurization after filling, not for sterility but to reduce fungal contamination. Pasteurization can be used as an alternative to anti-fungicidal reagents for products that can withstand a low heat treatment of 60°C for 10 hours.
What are sterilization validations?
Sterilization validations validate sterilization processes. Sterilization validations determine the presence or absence of microorganisms on the product after undergoing a sterilization cycle. Sterilization cycles can be moist heat, chemical gas, radiation, and other sterilization mechanisms such as filtration. The most popular method for sterilization validation is an overkill method. Overkill methods are used to verify that a certain sterilization process can achieve a certain level of sterility even if the bioburden is higher than expected, in a difficult to sterilize location, or the sterilization cycle runs inefficiently. Depending on the goals of the sterilization validation, either a full-cycle approach or a reduced level of treatment known as a partial cycle approach will be performed. An example of a partial cycle approach is a half cycle approach. Overkill sterilization validations are governed by ISO 17655-1.
Why are sterilization validations important?
Sterilization validations are an important quality control step that verifies that sterilization methods effectively kill any microbes in a product. As microorganisms exist on every surface (including our body), microbes can be accidentally introduced during the manufacturing or packaging process in many ways. Some of the most common examples are contamination through the raw materials used, technicians, tubing/piping used to transfer product between development stages in a process, or the manufacturing environment itself. Sterilization validations are used to ensure that the sterilization process can appropriately kill any viable microorganisms that accidentally enter the product during manufacturing and keep patients safe during parenteral product use.
Summary
Overall, pasteurization is a method to reduce the amount of bacterial and other harmful microorganisms in a product. Pasteurization is not robust enough to meet the sterilization requirements for parenteral products. However, some parenteral products may undergo a pasteurization process after filling to reduce fungal contamination when appropriate. When it comes to product sterility, sterilization validations are imperative for regulatory approval of parenteral products. Maintenance of sterility ensures that patients will not be at risk of infection following product use. Ensure you choose a contract testing organization that can provide appropriate sterilization validations for your parenteral product needs.
Ethide Labs is a contract testing organization specializing in Sterilization Validations & Sterility Testing. Ethide Labs also offers EO Residual Testing, Microbiology Testing, Cytotoxicity Testing, Bacterial Endotoxin Testing, Bioburden Testing, Package Integrity Testing & Environmental Monitoring services for medical device companies and allied industries. Ethide is an ISO 13485 certified facility.
References
International Organization for Standardization. Sterilization of health care products- Moist heat- Part 1: Requirements for the development, validation, and routine control of a sterilization process for medical devices. Geneva (Switzerland): ISO; 2006. (ISO 17665-1:2006/(R)2016).
Melissa Conrad Stöppler. Medical Definition Of Pasteurization. Medicine Net. 2021.
United States Pharmacopeial Convention. <1115> Bioburden Control of Non-Sterile Drug Substances and Products. Rockville, MD, USA. 2021. (USPC <1115>).
