Understanding the Concept of Bioburden

Products or components employed in the pharmaceutical or medical arena call for control of microbial degrees developed during processing and handling. The numbers of microorganisms present on such items is acknowledged as the ‘bioburden’.  Bioburden or microbic limit examination is executed on pharmaceutical products and medical products as a quality check measure.  Read more about Pharmaceutical Supply Chain Strategies

Products or components utilized in the pharmaceutical or medical area call for control of microbial levels during processing and handling. Bioburden or microbial limit testing on these products establish that the demands are met.

Bioburden of raw material as well as finished pharmaceutical products could assist to ascertain whether the product follows the prerequisites of the BP, Ph. Eur. or USP. Bioburden testing of constituents could demonstrate the usage of adequate control measures during the preparation and handling.

Bioburden, according to the University of Rochester glossary, is the number of microorganisms with which an object is contaminated. This unit is assessed in CFU (colony forming units) per gram of product. In industry the number of measured CFU should not exceed an un-processed bulk action limit. These limitations are required by the FDA and similar regulatory bodies to ensure the acceptability of a drug product. The drug is also required to be tested as a bulk drug substance (bds).

Given the nature of the devices, organism levels equate to low levels of (acceptable) contamination through to sterility: bioburden testing protocols must ensure that the results truly reflect the degree of contaminant present. Consequently, the procedures for removing of organisms from the devices must be verifiable as to the degree of removal achieved, so that justifiable correction factors can be used before the final bioburden result is described.

Steps which may influence laboratory results include:

• Sample preparation

• Extractants used to remove/enumerate microorganisms

• Time allowed for removal/dissolution

• Aids to removal, such as ultrasonics or agitation

• Subsequent handling of the removed microorganisms, including plating and incubation

All of these will contribute to the correction factors that will be used before a realistic bioburden figure is reported.

Substantiation of the test processes for devices may be performed by immunizing with known levels of bacterial spores and so subjecting to normal laboratory procedures – the results (received vs. expected) will then bear the correction to be used. As an alternative, the device may be subjugated to repeated organism removal procedures and the percentage of total organisms present removed by a single rinsing ascertained. A correction constituent can then legitimately be used for routine bioburden monitoring.

Validation for raw materials or intermediates of finished products may also be carried out, as it is a pharmacopoieal prerequisite for the bioburden testing to be considered valid. Individual aliquots of sample in diluents are spiked with known levels of specified organisms, which then carry out the normal testing process alongside a control. Recuperation of organism, as compared with the control, has to be within specification or the test is considered invalid.

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