-
Oil droplets accumulated on top of oil free serum. How?
I made this niacinamide serum 8 days ago.
Niacinamide 5%
Lactic acid 5%
Peg 12 dimethicone 0.1%
Phenoxyethanol 0.5%
Salicylic acid 0.1%
Citric acid 0.2%
Piroctone olamine 0.006%
Caprylhydroxamic acid 0.05%
Water
pH 4.
Piroctone olamine and Caprylhydroxamic acid dissolved in phenoxyethanol then added. Salicylic acid added when it was hot. Everything dissolved properly and product was clear.
After 8 days there are some oil droplets on top of the serum. Although this formula doesn’t have any oil or anything that is not water soluble.
What would be happening?
-
3 Replies
-
I’m curious, did you find the “culprit”?
-
How could the pH be 4 with all those acids? Are you testing the pH of the product or the 10% solution in distilled water? Try the latter. And make a buffer with sodium citrate to prevent pH fluctuations.
Oil droplets could be the contaminants in your plastic bottle or in your materials, if they’re ever oil-droplets in the first place. I assume they are the recrystalized SA or Piroctone olamine because these two have poor solubility in water. Use solubilizers like glycols, Peg-8 and polysorbates.
Log in to reply.