Total aerobic microbial count

In the general chapter on microbial attributes of nonsterile pharmaceutical products, the guidance suggests that the presence of microbial contaminants in nonsterile products [25] can reduce or inactivate the therapeutic activity of the product and has the potential to adversely effect the health of the patients and recommends manufacturers to ensure that contamination levels are as low as possible for finished dosage forms. Microbial enumeration limits for raw materials (total aerobic microbial count and total combined yeasts and molds count) and finished dosage forms are described. For inhalation, nasal, and topical routes of administration, tests for total aerobic microbial count and total combined and yeast and mold count,... 

P. aeruginosa, and S. aureus are recommended. For vaginal preparations, testing for total aerobic microbial count and total combined yeast and mold count, E. coli, S. aureus, and C. albicans is recommended, while for oral liquids and solids, testing for total aerobic microbial count and total combined and yeast and mold count and... 

Sections 5.1.4 and 5.1.8 of the European Pharmacopoeia [61, 62] specifies microbiological quality criteria for non-sterile pharmaceutical preparations and raw materials. They are stated as Total Aerobic Microbial Count (TAMC) and Total combined Yeast and Mould Count (TYMC) (see Sect. 19.6.3) and requirements regarding specific micro-... 

Test methods for the microbiological examination are described in Ph. Eur. Sections 2.6.12 [65] and 2.6.13 [66] respectively. Section 2.6.12 describes qualitative methods for the determination of the total aerobic microbial count and the total yeast and mould count. Section 2.6.13 describes tests for specified organisms. 

The total aerobic microbial count (TAMC) is defined as the number of colonies observed on casein soya bean digest agar. The total combined yeast and mould count (TYMC) is defined as the number of colonies observed on Sabouraud-dextrose agar. The assessment consists of four steps sampling, sample preparation/testing, incubation, and interpretation. 

Potential level of microbial contamination (total aerobic microbial count, total yeast and mould count)... 

In general, bioburden counts in parenteral solutions are obtained by conducting the total aerobic counts and total yeast and mold counts as specified in the USP microbial limits test (61) or an equivalent test [72], In addition, membrane filtration of larger than specified volumes may also be used to detect any microbial contamination when sample results are expected to contain a negligible number of microbial flora or in the presence of potential confounding factors, such as antimicrobial... 

Usually, total aerobic bacteria, molds, and yeasts are counted by using a standard plate count in order to test the microbial limits. The microbial limit test may be customized by performing a screening for the occurrence of Staphylococcus aureus, Pseudomonas aeruginosa, Pseudomonas cepacia, Escherichia coli, and Salmonella sp. [56],... 

Various dry powder attributes are assessed at release and on stability. These include physical characteristics such as powder appearance, content uniformity, delivered dose uniformity, and particle size distribution. Chemical attributes that may be assessed include drug content, purity, and identity as well as the water content of a powder. Dry powders may also undergo microscopic evaluation for foreign particulate matter, unusual agglomeration, and particle size. Microbial limits also should be examined, including the total aerobic, yeast, and mold counts. The presence of specific pathogens should be ruled out. The dry powders also may be dissolved to test for pH level. In addition, certain compendial requirements for content and delivered-dose uniformity should also be measured. 

Microbial limit tests, as described in USP 24-NF 19 (<61>) provide the information necessary to conduct bioburden counts by quantitative estimations of viable aerobic microorganisms in pharmaceutical articles, raw materials, and finished dosage forms. Consult the EP or JP for any differences in these methods from those of the USP. Note that USP (<61>) is currently under revision and that the next version will be fully harmonized between the USP, EP, and JP. The microbial limit test comprises the total aerobic bacterial (microbial) count (TAG), the total combined yeasts and molds count (TYMC), and tests for indicator organisms. Bioburden tests are also referred to as total viable counts. This test estimates the total number of viable (culturable) aerobic microorganisms in various items including parenteral UBPS. The total viable count is obtained by adding the counts from the TAC and the TYMC. 

Microbial limits There may be a need to specify the total count of aerobic micro-organisms, the total count of yeasts and molds, and the absence of specific objectionable bacteria. The source of the herbal material should be taken into account when considering the inclusion of other possible pathogens (e.g., Campylobacter and Listeria species) in addition to those specified in the European Pharmacopoeia. Microbial counts should be determined using pharmacopoeial procedures or other validated procedures. The European Pharmacopoeia gives guidance on acceptance criteria. 

Total microbial populations are often higher in no-till soils. In a study comparing surface soils from long-term no-till and conventional tillage plots at seven United States locations, counts of aerobic microorganisms, facultative anaerobes, and denitrifiers in no-till soils were 1.14-1.58, 1.57, and 7.31 times higher, respectively, than in the surface of plowed soils (Doran, 1980). 

Microbial limits Total viable count for aerobic bacteria and yeasts/molds. X X... 

Tests for microbial limits may also have to be considered depending on the nature of the API, its method of manufacture, and its intended use. Sterility testing may be appropriate for APIs that will be used in parenteral or oral solution products that are sterile. Endotoxin testing may be needed for APIs intended for injectable products. Testing for the total count of aerobic microorganisms, yeasts, and molds and the absence of specific objectionable bacteria, such as Staphylococ-cus aureus, Escherichia coli. Salmonella, and Pseudomonas aeruginosa, may also be required. The tests described in the various compendia are generally used. 

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