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Stability Test
Hi Everyone
Can you help me regarding stability test?
We dont have Standard Operating Procedure for Stability Test, I just want to know, in cosmetics products, do we have a “universal procedure” ? I mean a procedure that most of R&D or Product developer follows.Thanks in advance
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8 Replies
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Here is the procedure that I use.
https://chemistscorner.com/how-to-stability-test-a-cosmetic-formula/This is pretty much how most people do it in the cosmetic industry. The PCPC publishes stability test procedures but it’s pretty much like the one I posted.
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Thank you ..
I have questions Sir @Perry , (I hope you dont mind)
8weeks(@45C) = 1 year, meaning, I need to store my sample in the oven for 6months to prove that the product has 3 years shelf life?How to establish tolerance of the parameters (pH, viscosity)? do we have standards or is this from company’s decision?
Thank You Again Sir.
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Apart from testing for stability and viscosity how, if at all, is the stability of the active ingredient tested over the product shelf life (eg, VitC)?
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@nitrick - Stability this isn’t an exact science so a simple calculation like you did is a good estimate but should not be looked at as a rule. This article has some information about stability testing and labeling.
http://dgra.de/media/pdf/studium/masterthesis/master_engeler-plischka_c.pdf
For tolerance parameters that’s up to the company. +/- 10% seems reasonable but it really depends on what you are testing. I would say the difference matters when a consumer could reasonably tell a difference.
@Pete - That depends on the active ingredient. For most ingredients you would do some sort of analytical assay to determine how much of the ingredient is still in the product.
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Thanks Perry
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thanks @Perry
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One question again Sir @Perry, thank you
do you use Arrhenius Principle in predicting the shelf life ??
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Arrehenius Principle - Sort of. Stability testing assumes that higher temperatures will quicken the rate of any degrading reactions. This is why 45C can approximate 1 Year at RT. However, cosmetic systems are too complicated for it to be of much predictive use.
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