Microbial Limits
Microbial limits testing per USP <61> with additional specificity per USP <62> are common microbiological assays performed on non-sterile pharmaceutical preparations, the precursors to those preparations, and waters for pharmaceutical purposes.
This testing is typically performed in 3 phases:
- The first phase is a series of preparatory tests demonstrating that the Method is appropriate for use with the item(s) to be tested and that those items will not be inhibitory to microbiological growth.
- The second phase, specific to USP <61>, is a microbial enumeration test quantifying any aerobic bacteria, mold and yeast that may be present in the sample.
- The third phase, conducted according to USP <62>, is a series of tests intended to screen the sample for specific microorganisms which typically include S. aureus, P. aeruginosa, E. coli, S. enterica and C. albicans, with C. sporogenes included as a representative anaerobe.
If an acceptance criterion is specified in a monograph, then microbial limits are provided.