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Validation Services


In our lab we can perform several testing protocols according to GLP standards, among which are microbiology, stability, challenge, SPF testing, safety in use, claim support, effectiveness prooving, clinical studies, packaging approval etc.


In vitro testing of cosmetic products

- Microbiological tests

Microbial tests demonstrate the ability of the product to prohibit microbial growth during normal use. In this test the total viable count and pathogens checkup are performed. In Natura Laboratoriji microbiology testing is preformed according to ISO Guidelines.

Within the microbiological testing we check for:

  • Total aerobic plate count
  • Yeast and Molds
  • Staphylococcus aureus
  • Pseudomonas aeruginosa
  • Candida albicans


- Challenge test (Preservation efficacy test) of cosmetic product. We are performing challange test according to ISO 11930:2012. The efficacy of the preservation of a cosmetic product is an essential test, related to the product robustness against microbiological contamination. No preservation challenge test is needed if a product has high / low pH / is based on organic solvents / EtOH > 20% / low water activity and therefore this product may be considered as low risk product (ISO 29621:2010)


- Stability testing of cosmetic products

The physical and chemical characteristics are established during this test, ensuring that no changes in physical state of the finished product occur during transport, storage or handling of the product.


In vivo testing of cosmetic products and efficacy testing


- Patch testing


- Safety in use tests under dermatological control


- Efficacy testing


  • Skin hydration (Corneometer)
  • Sebum on the skin surface, scalp and hair (Sebumeter)
  • Assessing melanin content and erythema level (Mexameter)
  • Transepidermal waterloss and skin barrier function (Tewameter)
  • Elasticity measurement by suction (Cutometer)
  • pH-Measurement on skin and scalp (pH-Meter)
  • Gloss on skin, lips, nails and hair (Skin-Glossymeter)
  • Skin topography directly from the skin (Visioscan)
  • High resolution standardized full face photography for treatment documentation (VisioFace)
  • Assessing the skin macro relief by replica and oblique lighting (Visioline)
  • Assessing the skin micro relief (Skin-Visiometer)


- SPF testing: UVA in UVB

Efficacy studies


An understanding of the instruments and their limitations is essential when considering the design of clinical trials to support a claim. The methodology and precautions that have to be taken when measuring skin hydration using the Corneometer were described in the February issue of SPC and on[1] and this instrument is probably the most commonly used of all skin measuring devices (source:



With TEWL we specialize in safety and in vivo efficacy testing of nutritional complements for skin, cosmetic ingredients and cosmetic products. Evaluation studies, both sensory and bioengineering, are completed with various groups of volunteers (e.g. skin type, age, ethnical). An example of these tests would include sebum casual level testing and moisture level testing. Moisture is evaluated using a Corneometer® (C+K) and a Sebumeter® (C+K) is used to help determine sebum casual levels. TEWL measurements are performed using a Tewameter® (C+K). TEWL shows whether skin is in a good condition (source:

[1] Khazaka D & Uhl C, Taking measurements in principle and in practice, SPC, February, 45-46 & (2010)

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