To assess the preservation adequacy of your pharmaceutical products against microbial contamination, we use challenge testing for pharmaceuticals, also known as preservation efficacy testing (PET). 

Why challenge testing is important

We conduct challenge testing to substantiate preservation adequacy against microbial contamination, which may occur under reasonably foreseeable conditions of storage and use.

Ideally pharmaceutical products must be tested during their development stage.

Our scope of accreditation

In 2009 we received the EU Good Manufacturing Practice (GMP) certification by the Greek National Organization for Medicines (EOF) for microbiological testing (non-sterility) of human and veterinary medicinal products in various dosage forms.

Which challenge testing protocol we use

EP reference standard

The European Pharmacopoeia (EP) reference standards involves challenging the preparation in its final container, wherever possible. It uses a prescribed inoculum of suitable micro-organisms, (Pseudomonas aeruginosa, Staphylococcus aureus, E. coli, Candida albicans, Aspergilus brasiliensis).

Screening is performed by:

  • Storing the inoculated preparation at a prescribed temperature,
  • Withdrawing samples from the container at specified intervals of time
  • Counting the organisms in the withdrawn samples.

The results

The results are available within 35 days.

The preservative properties of the preparation are adequate if there is a significant drop or no increase, as appropriate, in the number of micro-organisms in the inoculated preparation at the temperatures and time prescribed.

You receive preliminary real-time reports on intermediate readings throughout the screening process. If you are based in the EU, we offer 24-hour courier service.

Minimum sample quantity


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