Testing categories
Microbiology

ULPL offers a variety of microbiological services, such as testing and analyzing products ranging from raw materials to finished goods from a broad range of industries. Our microbiology department is staffed with scientists experienced in testing AOAC, FDA, USP, and other internationally harmonized methods of microbiological testing.

ULPL has provided microbiological services to pharmaceutical, disinfectant, cosmetic, personal care, over-the-counter, dietary-supplement and many other industries.A more detailed list of the new USP <61> and <62> can be found below. Effective May 2009, the new USP <61> and <62> provide harmonization to the existing European Pharmacopeia method for testing non-sterile pharmaceuticals. This includes over-the-counter (OTC) and personal care products. The original total mictobial limits USP <61> underwent significant changes and split into two part new parts, USP <61> and <62>.

USP <61> Microbial Enumeration Tests such as total aerobic microbial count (TAMC), and total yeast and mold count (TYMC). The Microbial Enumeration Tests' changes lude new pass/fail criteria, longer ubation durations, and the disallowing of retests. Negative control is now required every time that the product is tested. Organism validation in TSA plates have changed to Staphylococcus, Pseudomonas, and Bacillus subtilis.

USP <62> Microbiological Examination of Non-Sterile Products: Tests for Specified Microorganisms. The modifications on microbiological medias for specific pathogens like Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Clostridia, bile–tolerant Gram-negative bacteria, and Candida albicans. Critical changes have been made to enrichment broth, ubation temperatures and ubation duration. Organisms such as Candida albicans, Clostridia species, and bile-tolerant Gram-negative bacteria may be required to be tested depending on product type per FDA and USP monograph. Negative control is required everytime that the product is tested.

List of our Microbiological Services:
• Cosmetic & Personal Care Microbiological Laboratory Services
• Pharmaceutical Industries Microbiological Laboratory Services
• Disinfectant Services
• Nutritional and Dietary Supplement Microbiology Testing

Cosmetic & Personal Care Laboratory Services

USP <61>, Total Aerobic Microbial Count, TAMC
• TAMC USP <61> provides very specific guidance for assessing total aerobic bioburden present in product.
• TAMC determines the total number of aerobic bacteria per mL (gram) of the cosmetics, personal care, or pharmaceutical product.
• TAMC method requires 48 to 72 hours incubation testing.
• TAMC is a mandatory mirobiological test for every lot of personal care product before sale to consumer.


USP <61>, Total Yeast and Mold Count, TYMC
• TYMC USP <61> uses Aspergillus brasiliensis (ATCC 16404-mold) and Candida albicans (ATCC 10231-yeast) as positive control.
• TYMC determines the total number of yeast and fungi per gram of the product.
• TYMC method requires a minimum of five to seven days of incubation testing.

Note: USP <61> and <62> methods of microbiological testing must include a positive control microbe and a negative control of diluents.

USP <51>, Antimicrobial Effectiveness
The antimicrobial efficacy test evaluates the effectiveness of preservatives used in the health, beauty, personal care, cosmetic and pharmaceutical products according to USP <51>. Each of the known strains of pathogenic organisms (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis) with predetermined colonies population are added to the product separately. Test sample colonies are counted at specified time intervals to determine the effectiveness of the preservative. The log reduction of the microorganism at day 7, 14, 21, and 28 are reported. This test requires 28 days of preservative efficacy.

The test demonstrates the efficacy of the product to stop the growth of pathogenic organisms. At least 100-150 mL or grams of the product are necessary to run this test. The antimicrobial effectiveness test is required only once per product unless the product formula or the manufacturing process involved any modification.

Criteria for Tested Microorganisms in Preservative Effectiveness:

Pharmaceutical Industries Laboratory Services

USP <61>, For Pharmaceutical Industry Testing
• USP <61>, Total Yeast and Mold Count, TYMC
• USP <62>, Microbial Examination Tests for Specified Microorganisms
• USP <51>, Antimicrobial Effectiveness Testing (Preservative Effectiveness)
• USP <1111>, Criteria Acceptance for Pharmaceutical OTC Product Testing

USP <61>, Total Aerobic Microbial Count, TAMC
TAMC USP <61> provides very specific guidance for assessing total aerobic bioburden present in products. TAMC determines the total number of aerobic bacteria per mL (gram) of the cosmetic, personal care or pharmaceutical product.TAMC method requires 48 to 72 hours incubation testing. TAMC is a mandatory mircobiological test for every lot personal care products before sale to consumer.

USP <61>, Total Yeast and Mold Count, TYMC
TYMC USP <61> uses Aspergillus brasiliensis (ATCC 16404-mold) and Candida albicans (ATCC 10231-yeast) as positive control.TYMC determines the total number of yeast and fungi per gram of the product. TYMC method requires a minimum of five to seven days of incubation testing.

Note: USP <61> and <62> methods of microbiological testing must include a positive control microbe and a negative control of diluents.

USP <62>, Microbial Examination of Nonsterile Products: Tests for Specified Microorganisms. USP <62> allows for the determination of the absence of, or limited occurrence of, specified microorganisms.

A listing of tests for specified organisms is as follows:
Bile-Tolerant Gram-Negative Bacteria: The presence of gram-negative bacteria is indicated by red precipitate around the colonies in Violet Red Glucose Agar. The product complies with the test if there is no growth of colonies.

ubation Time: 3 Days
Salmonella: The possible presence of Salmonella is indicated by the growth of well-developed, red colonies, with or without black centers in Xylose Lysine Deoxycholate Agar. The product complies with the test if colonies of the types described are not present.

Incubation Time: 3 Days
Pseudomonas aeruginosa: Growth of yellow-green to blue colonies in Centridmide Agar indicates the possible presence of P. aeruginosa.

incubation Time: 3 Days
Staphylococcus aureus: Presence of S. aureus is indicated by the growth of yellow or white colonies surrounded by a yellow zone in Mannitol Salt Agar.

ubation Time: 3 Days
Clostridia: An occurrence of fluorescent orange to bright red colonies in Columbia Agar indicates the presence of Clostridia.

Incubation Time: 3 Days
Candida albicans: Growth of white colonies in Sabouraud Dextrose Agar may indicate the presence of C. albicans.

Incubation Time: 5 Days

USP <51>, Antimicrobial Effectiveness Testing

The antimicrobial efficacy test as defined in USP <51> evaluates the effectiveness of an antimicrobial preservative in the health, beauty, personal care, or cosmetic product. The test is carried out in such a way that the product is challenged with the known strains of the microorganisms. Personal care and cosmetic testing samples are tested at different intervals to determine the survival of the organisms.

The test demonstrates the efficacy of the product to stop the growth of pathogenic organisms like staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis. The microorganism survival is monitored for the duration of 28 days and analyses are made on the 7th, 14th and 28th day.

Criteria for Antimicrobial Effectiveness
The requirements for antimicrobial effectiveness are met if the criteria specified under the following table are met. The term ‘no rise’ is defined as not more than 0.5 log10 unit higher than the previous value measured.

Criteria for Tested Microorganisms


USP <1111>, Microbiological Examination of Nonsterile Products: Acceptance Criteria for Pharmaceutical Preparations and Substances for Pharmaceutical Use.

Manufacturers must ensure a low bioburden of finished dosage forms by implementing current guidelines on Good Manufacturing Practice during the manufacture, storage, and distribution of pharmaceutical preparations.

Microbial examination and analysis of nonsterile products is performed according to USP <61> and <62>. The following tables list the criteria for both pharmaceutical preparations and substances for pharmaceutical use:



Please note that this list is not necessarily exhaustive, and for a given preparation it may be necessary to test for other microorganisms depending on the nature of the starting materials and the manufacturing processes involved.

Disinfectant Services

FDA guidelines for testing hard surface disinfectants to determine the efficacy of disinfectants against three organisms: Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella. This methodology is based on AOAC methods. There are several different claims made under this test. A log reduction greater than or equal to 99.99% of the bacteria must be observed in order for the disinfectant to pass this test.

Disinfectant Kill-Time:
This microbiology lab test examines the rate-of-kill antimicrobial formulations tested against single selected pathogenic microorganisms such as Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella, and produces data that provides basic information on such formulations. This test is often used to characterize kill kinetics and the substantial efficacy of a wide range of sanitizer products.

The time-kill study involves observing the same process at certain times in minutes intervals within exposure to create a more comprehensive report of the organism kill kinetics of the product, from 30 seconds to 15 minutes. A log reduction greater than or equal to 99.99% of the bacteria must be observed in order for the disinfectant to pass this test.

Nutritional and Dietary Supplement Microbiology Testing

USP <2021>, Microbial Enumeration Test
For non-sterile botanical and dietary supplement powders, capsules, and liquids, the following tests are required as stated by USP <2021>:
• Total Aerobic Microbial Count (TAMC)
• Total Yeast and Mold Count (TYMC)
• Absence of Gram-Negative Bacteria

USP <2022>, Absence of Specified Microorganisms
Good Manufacturing Practices (GMP) requires objectionable organisms be absent from nutritional and dietary supplement products as per USP <2022>:
• Absence of Escherichia coli
• Absence of Salmonella species
• Absence of Staphylococcus aureus
• Absence of Clostridium species

Retests can be performed to confirm doubtful results by making allowances with a larger sample size.

USP <2023>, Microbiological Attributes of Nonsterile Dietary Supplements
The recommended maximum, allowable acceptable microbial limits for dietary supplement ingredients and products according to USP <2023> are as follows. Recommended Microbial Limits for Dietary Supplement Ingredients and Products.