Microbial enumeration to USP <61> and tests for specified microorganisms to USP <62>, for non-sterile drugs, raw materials and finished products.
| Tests | Total aerobic plate count (TAMC) and total yeast & mold (TYMC) to USP <61>. Tests for specified micro-organisms to USP <62> on request. |
| Products | Non-sterile drugs, raw materials, excipients and finished products, for oral, topical and other routes. |
| Reported as | CFU per gram, per mL or per patch, compared with your specification or the USP <1111> criteria. |
| Method suitability | Shown for each product before results are reported, so the product does not hide organisms that are present. |
| Sample | Amount confirmed with the laboratory before shipping. |
| Price and timing | Quoted per project. |
| Accreditation | Performed under the laboratory’s ISO/IEC 17025:2017 quality system. |
Bioburden counts the micro-organisms in a product that is not required to be sterile and compares the count with the product’s specification. Products that must be sterile, such as injectables, are tested for sterility instead (sterility testing, USP <71>). The product and its specification decide which applies.
The total aerobic plate count (TAMC) counts the bacteria and fungi that grow on soybean-casein digest agar. The total yeast & mold count (TYMC) counts those that grow on Sabouraud dextrose agar. USP <62> tests for the absence or limited occurrence of specified micro-organisms: bile-tolerant Gram-negative bacteria, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus, Clostridia and Candida albicans. Which of these apply, and to what amount of product, comes from the product’s specification; USP <1111> gives the general criteria by route of use in the limits table below.
USP <61> describes how each kind of product is prepared so that organisms can be recovered from it. The count is made by membrane filtration or a plate count; the most probable number method is the least accurate but can suit some products with very low counts. The method is chosen for the product and shown to be suitable before results are reported. Tell us your product type and we confirm the preparation and method with you.
| Product type | How the sample is prepared |
|---|---|
| Water-soluble products | Dissolved or diluted, usually 1 in 10, in buffered sodium chloride-peptone solution pH 7.0, phosphate buffer pH 7.2 or soybean-casein digest broth, adjusted to pH 6 to 8 if needed. |
| Non-fatty products that do not dissolve in water | Suspended, usually 1 in 10, in the same diluents. A surface-active agent such as polysorbate 80 (1 g/L) may be added for poorly wettable materials. |
| Fatty products | Dissolved in isopropyl myristate sterilized by filtration, or mixed with the minimum quantity of sterile polysorbate 80 or another non-inhibitory surfactant, warmed to not more than 40 °C (45 °C in exceptional cases), then diluted 1 in 10. |
| Aerosols and sprays | Transferred aseptically into a membrane filter apparatus or a sterile container. The total contents or a set number of metered doses from each container is used. |
| Transdermal patches | Release liners removed, patches laid adhesive side up and covered with sterile porous material such as gauze, then shaken for at least 30 minutes in a diluent containing polysorbate 80 and/or lecithin. |
Source: USP <61> as harmonized with the European and Japanese Pharmacopoeias (JP 4.05 harmonized text).
General acceptance criteria from USP <1111>, in CFU per gram or per mL unless noted. A limit of 101 allows up to 20, 102 up to 200 and 103 up to 2,000. Your monograph or product specification sets the limit that applies.
| Route of use | TAMC | TYMC | Specified organisms, absent in |
|---|---|---|---|
| Oral, non-aqueous (tablets, capsules, powders) | 103 | 102 | E. coli (1 g or 1 mL) |
| Oral, aqueous (solutions, syrups, suspensions) | 102 | 101 | E. coli (1 g or 1 mL) |
| Rectal | 103 | 102 | None listed |
| Oromucosal, gingival, cutaneous (creams, lotions, ointments), nasal, auricular | 102 | 101 | S. aureus and P. aeruginosa (1 g or 1 mL) |
| Vaginal | 102 | 101 | P. aeruginosa, S. aureus and C. albicans (1 g or 1 mL) |
| Transdermal patches (per patch, including adhesive layer and backing) | 102 | 101 | S. aureus and P. aeruginosa (1 patch) |
| Inhalation* | 102 | 101 | S. aureus, P. aeruginosa and bile-tolerant Gram-negative bacteria (1 g or 1 mL) |
| Substances for pharmaceutical use (raw materials, APIs, excipients) | 103 | 102 | As the monograph requires |
*Special requirements apply to liquid preparations for nebulization. Source: USP <1111>, Tables 1 and 2.
The product, its route of use, the specification or monograph limits and the number of lots. We confirm the sample amount, method and price before you ship.
Questions about a sample or a method, call 360-967-7010 or email [email protected].
