
About Stability Testing
Hi there!
I really need some help on cosmetic accelerated stability testing.
I know that there ain’t no official guideline about it, so sometimes you can get a little lost/confused when you truly have to conduct a stability testing. I already studied some guidelines, like the IFSCC Monograph, the Colipa guideline, and ANVISA stability guide (Brazil), but I’m still confused about some topics. I know that there’s a lot of cosmetic systems, and they are all complexes, but I’m talking specifically about the stability of emulsions and shampoos/liquid soaps, since I normally don’t formulate makeup products.
So, my main question is: how do you truly ‘predict’ the expiration date of a cosmetic formulation? If my formulation (a emulsion) remains stable at 45ºC for three months (in an incubator) how long can I predict at normal conditions? 2 years? 3 years? What is the ‘rule’ that you guys follow?
The second one is: how can I conduct a ‘in real time’ stability testing? I mean, when the product is already being sold at the market. What is the periodicity of the readings?
Thanks in advande! 🙂
Best regards,