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Compendial Testing

Non-sterile is not un-specified.

A non-sterile product still has a number to hit and a list of organisms it must not carry. USP <61> gives you the count. USP <62> gives you the absence. We run both on the same sample, against your specification.

USP <61>USP <62>USP <1111>
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Two chapters, one release decision

USP <61> enumerates: total aerobic microbial count and total combined yeast and mold count, reported against the limits for your dosage form. USP <62> screens for absence: the specified organisms that disqualify a product regardless of how low the total count is. A product can pass one and fail the other, which is exactly why release testing runs both rather than treating the count as a proxy.

Choosing the right limits

USP <1111> maps recommended limits and the organism list to the route of administration and dosage form — an oral aqueous preparation, an oral solid, a herbal product and a topical each carry a different combination. We will work through that mapping with you rather than testing a default panel, so you are not paying for screens your product does not need or, worse, missing one it does.

  • Escherichia coli, Salmonella species, Pseudomonas aeruginosa and Staphylococcus aureus
  • Bile-tolerant Gram-negative bacteria, Candida albicans and Clostridia where the dosage form calls for them
  • Presumptive positives confirmed and identified to species rather than reported as a presumptive
  • Method suitability on your matrix before any routine testing begins

What you get back

  • TAMC and TYMC counts reported against your release specification
  • A stated result for each specified organism screened, with the method used
  • Your method suitability report covering recovery and neutralization on the matrix
  • Species-level confirmation of any presumptive positive, not a presumptive result
  • A release-ready certificate your quality unit can sign against
What's included

The scope of microbial limits testing.

USP <61> enumeration

TAMC and TYMC by plate count or membrane filtration, reported against your release specification.

USP <62> specified organisms

Screening for E. coli, Salmonella, P. aeruginosa, S. aureus, bile-tolerant Gram-negatives, C. albicans and Clostridia.

Method suitability

Recovery proven on your actual matrix, with antimicrobial activity neutralized.

Specification setting

Help mapping USP <1111> recommended limits to your dosage form and route of administration.

Confirmatory identification

Presumptive positives confirmed and identified to species by MALDI-TOF.

Cosmetics, supplements & OTC

Routine release programs for personal care, nutraceutical and OTC monograph products.

Common questions

Microbial Limits Testing, answered.

Which specified organisms do I actually need to test for?
It depends on the route of administration and the dosage form, and USP <1111> sets out the mapping. Oral aqueous preparations are screened for E. coli; oral solids and products containing raw natural material typically add Salmonella and bile-tolerant Gram-negative bacteria; topical and transdermal products are screened for S. aureus and P. aeruginosa. Send us the dosage form and route and we will confirm the panel before quoting.
What is method suitability and why does it come first?
It is the demonstration that your product does not suppress the very organisms the test is looking for. Preservatives, alcohols, surfactants and actives all inhibit recovery, and a product tested without validated neutralization returns clean results that prove nothing. Suitability establishes the dilution and neutralization scheme, runs once per product, and is repeated when the formulation changes.
Do you test cosmetics and dietary supplements?
Yes. Personal care, nutraceutical and OTC monograph products are a routine part of the workload, and the compendial framework is the same one applied to pharmaceutical non-steriles. We can set these up as a recurring release program with a standing specification rather than quoting batch by batch.
What happens if a specified organism is detected?
The presumptive is confirmed and identified to species before anything is reported — a presumptive Salmonella that turns out to be a harmless environmental isolate should not cost you a batch. If it confirms, you get the identification, the isolate record and the supporting data your investigation needs, and we will look at whether the source is plausibly the product, a raw material or handling.
How do USP <61> and <62> relate to each other?
They are complementary halves of the same release decision, usually run together on one sample. USP <61> is the enumeration test — how much is there. USP <62> is the absence test — whether specified organisms are present at all. A low total count does not demonstrate absence of E. coli, and an absence result says nothing about total load, so neither chapter substitutes for the other.
Often run together

Related testing.

Bioburden Testing

Total aerobic microbial count and total yeast and mold count on raw materials, in-process samples, water and finished units — the number your sterilization cycle is validated against.

USP <61>ISO 11737-1

Stability Studies

Chambered storage, a pull schedule you don't have to manage, and microbiological testing at every time point — the evidence behind a shelf life or a beyond-use date.

ICH Q1A(R2)USP <1150>USP <797>

Growth Promotion Testing

Lot-by-lot qualification of your culture media — proof that every batch of plates and broth recovers the compendial challenge organisms before you trust a result to it.

USP <61>USP <62>USP <71>

Ready to scope your microbial limits testing?

Send us the product and the claim you need to support. We'll confirm the method, the sample count and the turnaround before anything ships.

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