• Quality Assurance

    We guarantee that the methods we use for microbial control keep the highest possible quality.
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    All our equipments are validated and regularly calibrated and re-qualified.
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Method Suitability Test

Method validation with MST or IFT


Before an analysis of raw material and/or end product can be done, a MST (Method Suitability Test) or IFT (Interfering Factor Test) needs to be performed. This is done in order to control the effect of microbial growth in the presence of product but also to verify that the method itself is suitable (for example; is the product filterable?). If a method or product is changed, a new MST or IFT might be necessary to perform in order to assure the validity of the test.

We perform method validations when introducing a new product or raw material for enumeration tests , test for specific mikroorganisms, sterility control and endotoxin tests.

MST for enumeration of microorganisms is done by inoculating the product with ≤ 100 CFU of microorganisms, defined by the pharmacopoeia.  Ph Eur 2.6.12 / USP describes inoculation and recovery of Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans and Aspergillus brasillensis with suitable substrates.

MST for specific microorganisms is done by inoculating the product with < 100 CFU of microorganisms, defined by the pharmacopoeia.  Ph Eur 2.6.13 / USP describes inoculation and recovery of Escherichia coli, Salmonella, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridia, Candida albicans and bile tolerant gram negative bacteria with suitable substrates.

Interfering Factor Test (IFT) for endotoxins verifies the method of choice by pointing out possible inhibitory or enhancing properties of the product. The validation includes testing of different concentrations/dilutions of the product in order to set the detection limit below the specification limit, also called Maximum Valid Dilution (MVD). The validation is described in Ph Eur 5.1.10 “Guidelines for using the test for bacterial endotoxins” and USP . For new parenteral products, IFT is required for three different production batches. This is described in Ph Eur 5.1.10.

Analysis result, response time

Based on the degree of required method development the analysis time could vary but normal time requirement from sample arrival to analysis report-out are approximately 20 business days.