The term sterility refers to the absence of viable microorganisms; bacteria, germs and viruses in the product. Viable microorganisms multiply in the product, eventually destroying it and making it unsafe to use. It is therefore important to validate sterility. Pharmaceutical manufacturers are required to ensure the sterility of their products, especially those intended for parenteral or implantable use. Therefore, the guarantee of sterility ensures that these products are of high quality, efficacy and safety in use. Sterility Assurance Level (SAL) is the ratio that enables sterile drug manufacturers to give an arbitrary number to show the level of sterility in their products.
The concept of the level of guarantee of sterility
As mentioned above, SAL is a ratio. Gives the probability that a viable microorganism is present in the product. For example, an acceptable sterility guarantee level is 10-6. This means that for every million products that have undergone sterilization, there is at least one viable microorganism. However, there is a difference in SAL depending on the intended end use of the product and the stability of the product for sterilization. For example
• Assurance Standard 10-6 also referred to as pharmaceutical sterilization is intended for heat-resistant intravenous pharmaceutical products
• Standard Level Assurance 10-4 (SLA 10-4) referred to high level sterilization intended for heat resistant medical devices
• Standard Level Assurance 10-3 (SLA 10-3) referred to as low level sterilization intended for reusable medical devices that have been validated after cleaning.
However, sterile pharmaceutical factories face the problem of evaluating the success of the sterilization process used. It is impossible to score a standard 10-6 guarantee on a trial. Therefore, to overcome this limitation, the level of sterility assurance for sterilization is obtained from model experiments. The conclusions drawn from these experiments confirm a certain standard level.
In this case, The level of sterility guarantee They can be used to determine how many microbes are destroyed under certain sterilization conditions. In this case, a predetermined number of microorganisms undergo the sterilization process. Then the number of microorganisms is determined after testing. The biomarkers were contaminated with maximum resistant microorganisms for the specified sterilization process. This enables the containment of all possible microorganisms subject to sterilization.
For example, an sterilization process that destroys 106 resistant microorganisms in a biomarker can ensure a standard of 10-6. Usually the “half-cycle method” is used. It involves exposing the resistant microorganism in biomarkers to half of the conditions expected in the actual sterilization process. The resistant organism is often subjected to half the time, but not all conditions of other sterilization procedures are altered. Therefore, to ensure that the actual sterilization process is successful, the “half-cycle method” must achieve the corresponding sterilization guarantee level. This means that if the “half-cycle method” sterilization process achieves a standard assurance level of 106, it will guarantee a sterilization assurance level of 10 to 6 when applied to the finished product. The “half-cycle method” test ensures that the final product is subject to “overdone” conditions.