Using USP <61> to determine Microbial Enumeration

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DYNALABS provides USP <61> as the pinnacle test to determine Microbial Enumeration (aka bioburden) in non-sterile samples. This microbial analysis acts as a quasi-sterility test with an expected CFU count for monitoring the microbiological profile of a product’s ingredients and of finished products.

The presence of certain microorganisms in nonsterile preparations may have the potential to reduce or even inactivate the therapeutic activity of the product and has a potential to adversely affect the health of the patient. Manufacturers have therefore to 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 of nonsterile products is performed according to the methods given in the texts on Microbial Enumeration Tests 〈61〉 and Tests for Specified Microorganisms 〈62〉. Acceptance criteria for nonsterile pharmaceutical products based upon the total aerobic microbial count (TAMC) and the total combined yeasts and molds count (TYMC) are given in Tables 1 and 2. Acceptance criteria are based on individual results or on the average of replicate counts when replicate counts are performed (e.g., direct plating methods).

         –USP 40/ NF 35 <1111>
General Chapters-Microbiology 2015 Expert Committee

DYNALABS tests USP <61> in a dedicated microbiological laboratory utilizing cGMP processes.  We perform USP <61> Method Suitability to ensure product compatibility with certified ATCC organisms for growth promotion.  The following product types are

  Method 1 Aqueous
  Method 2 Aqueous Neutralization Required
  Method 3 Suspension
  Method 4 Suspension Neutralization Required
  Method 5 Fatty
  Method 6  Fatty Neutralization Required
  Method 7 Aerosols
  Method 7 Aerosols Neutralization Required
  Method 9 Transdermal


Recommended Raw Material Qualification, Taken from USP 1229.3