Sterility testing plays a vital role in the manufacturing processes of pharmaceutical and healthcare products. Its purpose is to ensure that any products intended for injection or implantation into the human body are free from any viable microorganisms. The main objective is to identify the presence of any contaminating microorganisms, such as bacteria, fungi, or yeast, which could pose a risk to the safety of the product. Regulatory bodies like the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have established stringent guidelines for sterility testing in the pharmaceutical industry.
Adhering to these regulations is crucial for obtaining product approval and market authorization. At Chromak Research, we specialize in providing Sterility Testing USP services for sterile pharmaceutical products, medical devices, and water.
Methods of Sterility testing
There are various methods for sterility testing, including membrane filtration, direct inoculation, and isolator-based methods. Each method has its advantages and limitations, and the choice depends on the nature of the product being tested.
- Membrane Filtration: This technique involves the passage of the product through a membrane filter that traps microorganisms. The filter is subsequently placed in an incubator, and any microbial growth is observed. In this approach, the test sample effluent is moved onto a cellulose nitrate or cellulose acetate membrane filter that can retain microorganisms. Depending on the product being tested, specially designed membranes may be utilized. The filter is then transferred to two specific nutrient test media and left to incubate for a period of 14 days. Membrane filtration allows for the processing of large sample volumes and facilitates the removal of substances that hinder the growth of microorganisms through the use of specific rinse agents. This method is suitable for testing soluble solids, oils and oily solutions, ointments, creams, antibiotic solids, aerosol products, and devices with sterile pathways.
- Direct Inoculation: In this approach, the product is introduced directly into a suitable culture medium, and the growth of any microorganisms is closely monitored. With the direct inoculation method, the product or medical device remains in direct contact with the test media throughout the entire incubation period. Test samples or portions of the sample item (SIP) are immersed in the test media and incubated for a duration of 14 days, allowing any microorganisms present on the sample to thrive and multiply under optimal conditions. Direct inoculation offers the advantage of requiring a smaller sample volume and is particularly beneficial for samples that cannot undergo membrane filtration, such as surgical sutures, gauze, and surgical dressings.
- Isolator-Based Methods: Isolators provide a controlled environment for performing sterility tests, minimizing the risk of contamination during testing.
The drug development process necessitates dependable sterility testing and the creation or verification of product-specific methods. At Chromak Research, we have a proven history of providing assistance in testing cell lines, media, in-process materials, and final products for the pharmaceutical, biopharmaceutical, and medical device sectors. Additionally, we possess a strong quality infrastructure to facilitate CGMP testing in accordance with USP and EP methodologies.
Chromak Research Labs conducts growth promotion testing to verify that every batch of media is capable of supporting the growth of the six microorganisms mentioned in the USP Sterility Tests. Before conducting a sterility test according to USP, our laboratory carries out method suitability testing for each specific product formulation to ensure the selection of an appropriate testing method.