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

Let customers speak for us

14 reviews
My Fave Four Apothekari products

The first product I purchased from Apothekari was the A for Anti Aging. I have Never been able to tolerate retinol products and always ended up bailing because of dry flaky skin. Until A for Anti Aging. It's Amazing! I have now added the Vitamin C, the Deodorant (Neroli Rose is my current favourite but the Lavender is great too), and most recently the More than Lip Service (thank you thank you thank you Apothekari :)). While deodorant and vaginal moisturizer may sound like odd gifts, these are my latest go-to's for the gal who has everything. All have become fans!

THIS WORKS! No odour for 24+ hours including a yoga session!

I'm blown away by how effective this is, and by how clean and well thought out the formula is. I'm not used to roll-on so that took a couple days to adjust to, but its so much more effective than the solids/creams i was using that it is totally worth it. I'm converted - and i think i have probably tried 90% of the natural deodorants out there over the last 10 years LOL. thank you for creating this.

I love this body oil!

This is so luxurious and moisturizing (i have dry, sensitive skin and most oils don't do the trick) and also miraculously absorbs very quickly. And the lemon rose scent is just transporting - i look forward to using this after my shower.

Bespoke Vitamin C Serum

I love it! Been using it for years. It’s so perfect to put on right after I wash in the morning. I’ve never been the greatest at sticking to a skin care routine but using the Vitamin C in the morning and A is for Anti-aging at night consistently over the years has kept my skin young and firm.
Would not want to imagine life (or my skin) without these two essentials. Thank you Sharmani!

*Received as press sample*

Pricing per bottle is definitely up there, but I think much like skincare, if you have struggled to find a deodorant that works for you, the price won't be as much of an issue because something like this can have a huge impact on your life. One bottle should last about 3-4 months with daily use which I think is fairly close to most deodorants. While I know there are baking soda-free options (baking soda can cause skin irritations due to pH disruptions) and options that use Deoplex, I have yet to find a combination of Deoplex and lactic acid which may be what's working for me. Honestly, the only thing I didn't enjoy was that "wet" feeling when I would first apply it, but after 15 seconds it dries down AND it doesn't stain clothing so that's a huge plus. Even though I received this as a press sample, I would buy this deodorant on my own as I didn't just smell good at the end of a long day, but I smelled like absolutely NOTHING which is WAY better to me than smelling like "I'm covering something up" or like body odour. I also trust and appreciate the research I know Apothekari has invested into making sure the formulation is scientifically sound so I know that's also partly where my dollars are going. I only need to apply once a day and I'm good to go so one bottle might even last more more than 4 months at the rate I'm going! HIGHLY recommend and even though all three scents had the same results, my preferred scent was the Lavender as it just one of my favourite scents overall!

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