How stable is your formulation?
I remember reading about this years ago and then stumbled on it while doing research for the next Cosmetic Science in 300 Seconds video. It was interesting enough that I thought I would share.
Archeologists have discovered a container of color foundation makeup that is over 2000 years old. It was found in a dig in Southwark which is just outside of the southern part of London.
The cream was made from animal fat, starch and tin oxide. When researchers made a modern version of the formula they said it left a smooth powdery texture when rubbed into skin. Of course, I’m not sure how different the starting raw materials were. The biggest differences would be in the purity of the compounds used.
Anyway, the article doesn’t say whether the formula separated but if it didn’t, that would be an incredible feat of formulating. Imagine a 2000 year long stability test. I’ve had some formulas that have lasted 4 or 5 years, but 2000? Wow.
Although the ancient formula may not have passed all the stability testing. According to the researchers when they opened the jar there was a strong pungent rotten eggs smell. Not quite the kind of thing you want to put on your skin.
But it leaves me wondering, how would you modify a formula to be stable for 2000 years?
