EMA publishes new questions and answers on Annex 1

The European Medicines Agency (EMA) publishes answers to frequently asked questions on good manufacturing practice (CGMP) and good distribution practice (GDP) on its website at irregular intervals, as discussed and agreed by the GMP/GDP inspectors' working group. The published questions and answers may also become obsolete and then be removed when the relevant guidelines are updated.

Four new questions have been added to the catalogue of Annex 1 questions:

1. What is the maximum Bioburden Level?


Update January 2019: This Q&A has been superseded by the Guideline on  "The Sterilisation of the medicinal product, active substance, excipient and primary container"  Please refer to this guideline for further information.. The specification limits for bioburden should be NMT 10 CFU/100 ml, in line with the guideline “sterilisation-medicinal-product and active-substance ref EMA/CHMP/CVMP/QWP/850374/2015)".

Note for guidance on manufacture of the finished dosage form - First version and Note for guidance: Manufacture of the finished dosage form.

When a prefilter is installed, unless otherwise justified, a bioburden limit of 10 CFUs/100 ml before first filtration is achievable in principle and is strongly recommended from a GMP point of view. Higher bioburden limits should not be justified by the high capacity of two consecutive bacteria retaining filters.

However, when appropriate justification is submitted (processes involving fermentation or other biological or herbal components, use of purified water for ophthalmic preparations, etc.), a bioburden limit of higher than 10 CFUs/100 ml before prefiltration may be acceptable. In such cases, it should be demonstrated that the first filter has the capability to achieve a bioburden prior to the last filtration of NMT 10 CFUs/100 ml, in line with the notes for guidance on manufacture of the finished dosage form (CPMP/QWP/486/95 and EMEA/CVMP/126/95).

2. Is rapid method valid for the detection of Microorganisms within Grade A and B


Rapid method is one of the alternative monitoring systems that may expedite the detection of microorganisms pending that the requirements of annex 1 points 9.28, 9.30 and 9.31) are fulfilled.

3. Is an isolator considered as "closed isolator" if the semi-continuous ingress and/or egress of materials during operations is conducted via reproducible biodecontamination steps (active VPHP material airlock)?


Annex 1 distinguishes two types of isolators:

  • Closed isolator systems exclude external contamination of the isolator’s interior by accomplishing material transfer via aseptic connection to auxiliary equipment, rather than use of openings to the surrounding environment. Closed systems remain sealed throughout operations;
  • Open isolator systems are designed to allow for the continuous or semi-continuous ingress and/or egress of materials during operations through one or more openings. Openings are engineered (e.g. using continuous overpressure) to exclude the entry of external contaminant into the isolator.

An isolator designed to interface with material transfer airlock that uses a reproducible bio-decontamination steps (active vapor-phase hydrogen peroxide (VPHP) decontamination) might be considered as a closed isolator as per Annex 1 glossary definition, provided that the interface can be shown to constitute an efficient barrier to the surrounding environment based on documented evidence from qualification/validation studies and monitoring data.

For instance. This might be possible , as long as the VPHP cycles are validated and filling chamber environment is protected by the sealed door (as barrier) while the integrity of airlock is broken during loading followed by decontamination cycle before opening the barrier again. Requirements of Annex 1 points 4.10, 4.11 and 4.12 should be considered.

It needs to be pointed out, that these elements should be discussed with the respective supervisory authority.

4. What are the requirements for the bioburden sampling to support parametric release?


Annex 1 point 10.4 states that for products authorised for parametric release, a supporting pre-sterilisation bioburden monitoring programme for the filled product prior to initiating the sterilisation cycle should be developed and the bioburden assay should be performed for each batch (sub batch) The sampling locations of filled units before sterilisation should be based on a worst case scenario and be representative of the batch. Any organisms found during bioburden testing should be identified and their impact on the effectiveness of the sterilising process determined. Where appropriate, the level of endotoxin/pyrogen should be monitored.

Annex 17 point 4.9 states that a pre-sterilization bio-burden monitoring program for the product and components should be developed to support parametric release. The bioburden should be performed for each batch. The sampling locations of filled units before sterilization should be based on a worst-case scenario and be representative of the batch. Any organisms found during bioburden testing should be identified to confirm that they are not spore forming which may be more resistant to the sterilizing process

The company should consider the bioburden by the batch or sub-batch to be sterilized.

A specific consideration should be given to the time between sampling, sterilisation and testing.

Any alternative to this approach should be thoroughly justified and should consider:

  • The materials involved including packaging materials;
  • Homogeneity of the bioburden within the different sub-batches;
  • Presence of the organisms;
  • Time between sampling and sterilisation.

The original version can be found on the EMA website at:  "EU GMP guide annexes: Supplementary requirements: Annex 1: Manufacture of sterile medicinal products".

Go back


Stay informed with the GMP Newsletters from ECA

GMP Newsletter

The ECA offers various free of charge GMP newsletters for which you can subscribe to according to your needs.

To subscribe, please click here.