Bioburden and It’s Applications and Methods
Bioburden is the term used to describe microbial contamination of a product prior to sterilization. Microorganisms can be introduced at any point during the manufacturing process through raw materials, the environment, humans, or during the final stage of cleaning and packaging. Since the sources of contamination can vary widely, a product’s bioburden can fluctuate from batch to batch, routine bioburden testing is recommended.
Bioburden testing analyzes a product to quantify viable (living) microorganisms thereby providing a measure of microbial contamination — in colony forming units (CFUs) — within the products.
Bioburden Testing Applications
Bioburden testing is most commonly performed by the pharmaceutical and medical industries for quality control testing of pharmaceutical and medical products. Bioburden testing ensures that pharmaceutical products.
Conducting a Bioburden Test
A bioburden test is conducted using culture media appropriate for the type of microorganism being targeted, and typically involves two primary methods to measure the total viable aerobic count,
1- total aerobic microbial count (TAMC)and
2- total yeast and mold count (TYMC).
Bioburden Testing Methods
In order to estimate the bioburden load of a product, a sample needs to be prepared according to its physical characteristics, i.e. whether the sample is water soluble, fatty or non-fatty, or in aerosol form. Once the sample is prepared, there are two primary methods used to quantify the microbial load: the membrane-filtration method and the plate count method.
1. Membrane-filtration method: sample is filtered through a membrane with a pore size of ≤ 0.45 micrometers to isolate the microorganisms from the sample. The filter membrane containing the isolated microorganisms is then placed onto the casein-soybean digest agar and incubated for at least five days at (30–35°C) in order to detect bacteria. To detect fungi, use sabouraud dextrose based culture media and incubate for five days at (20–25°C).
2. Plate count method: sample product together with melted casein-soybean digest agar is poured into a petri dish and allowed to solidify. It is then incubated for five days at (30–35°C) before the TAMC is recorded. For fungi, use sabouraud dextrose agar and incubate for five days at(20–25°C) before the TYMC is recorded.
3. Most probable number (MPN) method: is a statistical method used to estimate the number of viable microorganisms in a sample. It is considered less accurate than the above two methods, but it can be used to test products where the bioburden is determined to be too low to provide reliable counts using the above methods, or when neither of the above methods are available.
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Resource Person: Anas Salama Hemaid
