Microbial Limits Test
ILS perform Microbial Limit Testing to the EP and the USP. The testing is used to estimate the total number of viable micro-organisms present and for the absence of specific pathogens in pharmaceutical articles of all kinds.
The microbial limit (contamination) test is used to test the microbiological content of pharmaceutical products which are not designed to be sterile, or raw materials used in the production of other products.
The principle of the Microbial Limit Test is that each viable microbial cell present in a sample, will, when mixed with an agar medium, and after incubation, form a visible separate colony.
The enumeration of these colony-forming units (cfu), when taking into account sample preparation will give an estimate of the microbial population of the product under the specified incubation conditions.
Or that a range of dilutions of the sample, in a specified number of tubes containing a suitable medium and under specified incubation conditions, will give an estimate of the microbial population of the product using most probable number tables.
Or that filtering liquid samples, or dilutions of solid samples, through a membrane filter will retain any microbial cells on the filter and that each viable microbial cell present on the filter will, after incubation, form a visible separate colony when the filter is applied to the surface of an agar plate.
The enumeration of these colony forming units (cfu), when taking into account sample preparation, will give an estimate of the microbial population of the product under specified incubation conditions.
That non-selective enrichment, selective enrichment, selective plating and confirmatory testing will allow specific micro-organisms, which may be present in the sample, to be detected.
The presence of micro-organisms within purified water can also be assessed at ILS by performing a Total Viable Count using membrane filtration.
For more information or to obtain a free quotation for your testing requirements, please contact us
For pharmaceutical industry updates and information, including changes to regulations and methods, please go to the Industry Information page.