Comments on: Cosmetic Stability Test – Freeze Thaw Cycles

By: Perry

Perry — Mon, 05 Jul 2010 16:19:43 +0000

Please see our article on HLB formulating. http://chemistscorner.com/hlb-the-easiest-way-to-create-an-emulsion/

By: Prajakta Bhuskute

Prajakta Bhuskute — Mon, 05 Jul 2010 16:15:04 +0000

Thanks Perry
This is a very usefull information.
Can u please explain Hlb Calculation For a w/o emulsion system.

By: Perry

Perry — Mon, 07 Jun 2010 11:52:58 +0000

It really depends on the type of formula you are testing. 60C is probably too high a temperature to get any meaningful data for most products (esp. emulsions). The reason is that some of the raw materials will melt at that temperature and you get artificial negative stability results. If something is stable at 45C for 2 months, it is generally considered stable. Your 3 month standard is more extreme but if it’s stable there, then you’re in good shape.

Finally, 50g is probably not enough product to test. You should be using at least 100g. However, this depends on the formula too. If you are not testing viscosity then perhaps you can get away with a smaller amount.

By: Perry

Perry — Mon, 07 Jun 2010 11:49:38 +0000

A standard number of cycles for freeze/thaw tests is 3. I’m not sure I understand the second question.

Temperatures for a full stability should be near freezing, room temperature, and elevated temperatures. I’ve had success using the following temperatures. 4C, RT, 37C, 45C. But you might have different temperatures that are more convenient to use.

By: cris baysauli

cris baysauli — Mon, 07 Jun 2010 09:32:47 +0000

I would like to validate our stability method in formulating cosmetic products. Generally, after product formulation, we put 50 g samples under accelerated temperature testing at 45 degrees and 60 degrees. We consider a formulation to be stable after 3 months at 45 C and 2 weeks at 60 C. Is our method correct?

By: Bahman

Bahman — Sat, 29 May 2010 16:47:47 +0000

I have some doubts here:
How should we select the number of cycles and also the temperatures and what is the relation between these parameters and the field exposure?

By: Lisa

Lisa — Thu, 27 May 2010 00:15:52 +0000

Interesting, is there an industry standard method you could point me at? I work with food but I assume this could be applied with anything that is like a cream. it would be an interesting comparison.

By: Perry

Perry — Tue, 15 Dec 2009 18:45:11 +0000

Charbel – It doesn’t really matter that much. You just need it to be cold enough to freeze all the way through. 4C works for most products. -10C will work too but it’s not necessary how solid you freeze the sample. It just has to be frozen.

By: charbel Haddad

charbel Haddad — Thu, 10 Dec 2009 06:03:53 +0000

Dear Perry,

In step 3: what should be the temperature of the freezer ?

I did the Freeze thaw cycles before and I have used different temperatures ex: 4C, -10C .

Thank you

By: Joana Lou

Joana Lou — Tue, 08 Dec 2009 05:38:04 +0000

Can I ask for the specific storage conditions in the accelerated stability testing and real-time stability testing of cosmetic products in ASEAN countries?
I would also like to ask for the specific procedures involved in it. Thanks!