Archive - mars 2011

Harmonization of the Microbial Limits Test – Enumeration – at Rechon

This is a rerun from April 2010 and is one of our most appreciated and widely read blogs. It is Maj-Lis Olsson, Analyst and responsible for the QC Micro lab at Rechon, who is the skilled author.

Efforts to harmonize the microbiological tests had been ongoing in the industry for some time and we really looked forward to the day when it would be enough to do one test and be in compliance with both European Pharmacopoeia (Ph.Eur) and United States Pharmacopeia (USP). At Rechon Life Science, we began to validate the first raw materials according to the new harmonized Ph.Eur/USP/JP method a couple of years ago.

The microbial enumeration test is designed to count the number of CFU in a non sterile product or raw material. The method is to put the material into a solution and then plate aliquots to determine the CFU/gram (or mL) of initial material. The method of plating can be pour plate, spread plate or filtration of material and then placing the membrane filter on the surface of an agar plate.

The harmonised texts came into force in Ph.Eur on January 1, 2007 and on May 1, 2009 in USP. The harmonization also covers the Japanese Pharmacopoeia (JP).
 

Life before harmonization

Before the harmonization we did our own type of harmonization i.e. selecting the largest sample volume, the longest incubation times and using all the strains mentioned in either one or the other pharmacopoeia, just to be able to do one test instead of two. It was not possible to do this for specified microorganisms, so for E. coli we had to perform two completely different tests.

 

Life during harmonization 

We realized rather quickly that based on the changes in these harmonized chapters it was necessary to perform new suitability tests for almost all of our raw materials and products. The reason was that many essential test parameters changed, e.g. incubation time, media for enrichment, subculture and selection. Moreover, strains, acceptance criteria and the performance of the suitability tests were changed. The new chapter on the total count also describes more in detail how the different media are to be tested, which led to further changes.

The days were spent on: writing protocols and specifications, making a lot of media, pouring plates, testing media, diluting raw materials, diluting microorganisms, mixing organisms and diluted raw materials, making suitability tests, counting days and colony forming units. If the acceptance criteria were met reports were written. If the recovery was insufficient we started from scratch with new dilutions, neutralization and so on…….
When the reports were written and approved, methods were written, the staff was educated and the new tests were implemented.

Life after harmonization

 – Ahhh wonderful, everything is much more efficient now!

 

The nine chapters that were harmonized are:

European Pharmacopoeia (Ph.Eur)
2.6.12 Microbial Examination of Nonsterile Products: Microbial Enumeration Tests
2.6.13 Microbial Examination of Nonsterile Products: Tests for Specified Microorganisms
5.1.4 Microbiological Quality of Nonsterile Pharmaceutical Preparations and Substances for Pharmaceutical Use

US Pharmacopoeia (USP)
<61> Microbial Examination of Nonsterile Products: Microbial Enumeration Tests
<62> Microbial Examination of Nonsterile Products: Tests for Specified Microorganisms
<1111> Microbiological Examination of Nonsterile Products: Acceptance Criteria for
Pharmaceutical Preparations and Substances for Pharmaceutical Use

Japanese Pharmacopoeia (JP)
35.1 Microbial Examination of Nonsterile Products: Microbial Enumeration Tests
35.2 Microbial Examination of Nonsterile Products: Tests for Specified Microorganisms
7 Microbiological Examination of Nonsterile Products: Acceptance Criteria for
Pharmaceutical Preparations and Substances for Pharmaceutical Use

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