Category: Manufacturing and Bioprocessing
Purpose: The genus Mycoplasma represents a group of minute bacteria which have no cell walls. The species vary in size and morphology, cannot be Gram stained due to lacking a cell wall, and are parasites and commensals to cells in culture. Mycoplasmas are common in cell culture throughout the world, and some are pathogenic to humans. Due to these qualities, Mycoplasma detection testing is required across multiple compendia for therapeutic biologics. The four main compendia that require mycoplasma detection testing, the USP, the EP, the JP, and the FDA PTC all require a direct culture method and an indicator cell culture method to have a valid negative result for the detection of mycoplasma within a product matrix. Traditionally, when a product matrix is submitted for approval according to each compendium, a separate test has been required for each method per each of the four compendia. However, all four compendia have enough similarity between the methodologies that they can be harmonized. One set of tests, detection by direct culture and detection by indicator cell culture, can effectively be used instead of the four separate methodologies, with eight separate tests, to satisfy the compliance requirements across all four compendial requirements.
Methods: Breaking down each method, the direct culture method can be broken down into two components, agar inoculation and broth inoculation, allowing for review of the requirement categories across the compendium. The agar inoculation portion can be further separated into 9 categories for comparison (e.g., Sample Volume, Positive Control Organisms, Growth Promotion of Media, Incubation Times/Ranges, etc). The broth culture portion can be further separated into 12 categories for comparison. The indicator cell culture method can be separated into 17 categories for comparison across the 4 compendia.
Results: After breaking down the methods into each of the categories, a comparison between the compendia in each category was evaluated to determine the compendial requirement with the most structured criteria in each category. Each criterion was then evaluated again across the rest of the compendia to determine whether it met or exceeded the requirements across all of the compendia. These categorical criteria were then selected for each of the two methods to form an analytical method that would meet or exceed all of the compendial requirements across the four compendia as seen in Figure 1. These methods were then validated according to cGMP regulations to meet the requirements across all compendia.
Conclusion: Harmonizing the compendial testing for mycoplasma detection across the major compendia allows for one set of tests to satisfy the requirements for all of the compendia. This means that for each product matrix, one test can be used when filing for any or all of the indicated agencies, reducing the amount of testing, the overall time required to test for all of the compendial requirements, and the overall volume of product matrix needed for filing at multiple agencies. References: USP < 63 >, EP 2.6.7, JP General Information Chapter, PTC Guidance for Industry 2010 Chapter IV Section A.3.a