Stability testing cosmetics is an important step in the manufacturer of products to ensure that the end result is something that is effective and safe. Well formulated and stable treatments are not only safe and effective, they are also much more pleasant to use. Like many of you, I’ve purchased cosmetics that separate, or start to smell badly just a short period after opening. It’s possible that the manufacturer of these products may not have tested them adequately to ensure their stability under certain conditions.


Stability testing for cosmetics is a complicated process that involves 3 main tests:

  1. Physical and Chemical Integrity Tests. Evaluate color, odor/fragrance, pH value, viscosity, texture, flow, and emulsion stability (signs of separation)
  2. Microbiological Stability Tests. Evaluate the degree of contamination with bacteria, mold, and yeast.
  3. Packaging Stability Tests. Evaluate the impact of packaging on the contained product.

How To Stability Test

Companies can do stability testing for cosmetics in real time or under ‘accelerated’ conditions, which aim to speed up the results of real time. Most companies perform tests using “Accelerated” Conditions. The actual tests involved vary depending on the product, its packaging and its anticipated shipping, storage, display and use. The following tests may be conducted:

  • High Temperature Testing: High temperature testing is commonly used as a predictor of long-term stability. Storage and stability at a range of high temperatures (between 37 and 45oC) is a good predictor as to how long a product will maintain its integrity.
  • Cycle Testing: Often called a freeze-thaw cycle, the product is frozen and thawed three times testing a range of temperatures from below freezing to high room temperature.
  • Centrifuge Testing: Centrifuging is the process of rapidly rotating a product to force its contents (typically fluids) to separate out.
  • Light Testing: Formulas and packaging can be sensitive to UV radiation. Light testing helps to predict if the product or packaging will discolor in its chosen container.
  • Mechanical Shock Testing: As products are transported, shipping movements may damage them. Vibration testing can help to determine if this will happen. Products should also be monitored for changes in color, odor/fragrance, viscosity and pH value.

Microbiological stability tests assess microbial contamination either during the production and filling or during the use of the cosmetic by the consumer. These tests are very important to ensure that the treatment is safe and maintains its quality. In particular, we are concerned about dangerous bacteria.

Finally, cosmetics should also be tested to be stable in the container in which they are packaged.

The topic of stability testing for cosmetics sounds like a boring one. Yet, it is a complex process and an important one too. For your health and safety it’s imperative that the cosmetics you are using have gone through these widely recognized standard tests.


★ Reviews

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39 reviews

I'm loving this deodorant from Apothekari! I'm very skeptical about natural deodorants because I perspire a lot and had always used antiperspirants. Wanting to go more natural, I've tried a few natural deodorants and this is by far the best. I can apply in the a.m., go overnight, and work out the next a.m. without having to reapply. I also love the smell. I have scent sensitivities and this citrus-ginger mix doesn't bother me at all. Super-happy with my purchase.

My recent order of apothecary

I’m so pleased with my products! My skin is already more radiant, pores are tighter !

Great deodorant!

I’ve tried many natural deodorants with mixed results. The Apothekari deodorant works GREAT, even when doing intense workouts. I also like the scent of all of the products. The skin of my underarms seems to have improved texture as well. I will definitely repurchase.

It works wonders! But strong scent...

This is the first and only natural deodorant that has kept me fresh for more than 6 hours. I put it on at night after my shower and it keeps me Oder free for around 12 hours. LUMÉ couldn’t do that for me! I wouldn’t buy this particular scent again though, I thought it would have a nice balance between the Neroli and Rose, but I cannot smell Rose at all - in my opinion it comes off smelling very manly. Next time I will order the lavender and bergamot scent.

The deodorant is great, gently shake and roll on. It’s very watery so I rub my arms back and forth to get it applied everywhere and then wait for a second in front of the fan before putting on a shirt. But it sooo worth it!!! Amazing deodorant and no rashes! My skin feels healthy. I have been using it for about a month.

Game Changer!

I've tried prescriptions and other products that claim to help with vaginal dryness and none compare to this product. So natural and no added hormones or perfumes. A real game changer for me! Also BEST name for this!

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