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Degradation of Propylene Glycol (Oxidation)
Hello,
First of all I am very beginner to cosmetics formulation and if you found stupid terms or way to ask question, kindly ignore.
My batch was:
Titanium 30%
Zinc Oxide 10%
Kaolin 20%
Propylene Glycol 40%
Color (as per shade)I just mix these ingredients in a dough mixer and form a hard base. It looks great and work as aqua makeup. I pack this batch in jar. After 7 days all batch jars start extracting water like stuff. All my packaging got wet.
When I search this issue on google they says that propylene glycol react with oxygen and degrade.
After that I change Propylene Glycol with Glycerin. And amazingly glycerin did the same as propylene glycol extract water.
Required Features:
A base that can be easily applied with wet sponge. PG or Glycerin attracts water so I use these chemicals (no other requirement from these chemicals)I request that kindly suggest me what can I do with my batch so that I can extend shelf life of my product.
Shelf life only means that base maintain its look and hardness rather then become aqueous or soft.
Thanks in advance.
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6 Replies
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PG or Glycerin attracts water
You answered your own question. -
Belassi has it right. There is no solution to your two mutually incompatible goals.
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Have you actually thought this through? When I have trouble formulating, I find it useful to consider what I am doing in simple terms. In your case, I see:
“Combining 40% of basic metal oxides, with 20% of aluminium silicate - thus 60% of basic oxide/silicate mixture, with 40% of a polyol. (In this respect, propylene glycol and glycerine are so similar in their properties as to make little difference.)
Even if you package in hermetically sealed containers (thus eliminating the hygroscopic problem) the ingredients will separate because a polyol has no appreciable yield value; gravity will make the ingredients separate according to their density and particle size. -
@Belassi thanks for your reply. In this case should I go for some emulsion to mix with powder phase?
I mix all metal oxides together with kaolin and red oxide and yellow oxide in a mortar. (I call this phase powder phase)
Then I need to make a dough. In my beginning I use simple water but after 2 months water evaporated and aqua makeup converted into shrinked cake that was moving in packaging jar.
Could you please direct me to right path. Just need an emulsion that Hold my powder phase in stable shape.
I had tried polawax, water and paraffin emulsion but batch lost waterproofing and washed quickly.
And @Bobzchemist thanks to you too for keeping eye..
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I think it is too much solid form to suspend into an emulsion. If you want the emulsion to be waterproof or not easily washable, you can make an W/O emulsion or even an ointment.
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This is not a simple problem. You need a carrier liquid that is not hygroscopic but is water-soluble/water-dispersible so that it can be applied with a wet sponge, but not so water-soluble that it comes off the face too easily. Emulsions won’t work due to shrinkage. Ointments won’t work due to the wet sponge requirement.
It would be so much simpler to make a traditional pancake or hot-pour foundation. Have you considered this?
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