2% Salicylic Acid solution cloudy?
I’ve been trying to make a 2% Salicylic Acid serum (basically copying Paula’s Choice) but my resulting solution was cloudy.
The formula I used was:
10% Salicylic Acid in Propanediol + Propylene Glycol (50/50 mix of both) 20% Sodium Citrate 1% Polysorbate 20 3% Green Tea Extract (liquid) 1.5% Tetrasodium EDTA 0.15% Distilled Water 74.05% Liquid Germall Plus (haven’t added this yet) 0.3%
1. Mix 10% Salicylic Acid in 45% Propanediol and 45% Propylene Glycol
2. Mix Sodium Citrate, Tetrasodium EDTA, Green Tea Extract, Polysorbate 20, and Distilled Water in a separate beaker
3. Add in the 10% Salicylic Acid
After mixing the beakers together, I noticed that the final solution was cloudy. After letting it sit overnight, it didn’t look like the SA was precipitating but it was still cloudy. pic 1 pic 2 (same pictures as below) Oh, and the solution was pH 4.
The rest of my 10% SA stock however was still clear.
A redditor said that they had some experience with polysorbate making their product cloudy. So I did another test: (yes this only adds up to 99.7%. I left 0.3% blank for the Liquid Germall Plus I would’ve added).
6% Salicylic Acid in Propanediol + Propylene Glycol 33.33% Sodium Citrate 1% Distilled Water 64.87% Polysorbate 20 0.5%
1. Mixed Sodium Citrate into the Distilled Water
2. Added in the Salicylic Acid - At this point the solution was still clear, no precipitates
3. Added in the polysorbate 20 - when I mixed this in for a glass stirrer, it turned the solution cloudy. I used a hand mixer for 30 seconds afterwards to thoroughly mix it and it was still cloudy. No SA crystals though.
I also mixed a separate beaker without the polysorbate 20:
1. Added the 6% SA directly into water - saw small slivers of precipitate start to form
2. Added in the sodium citrate and put the beaker into a hot water bath for 1-2 min - solution cleared up and no more precipitates remained.
Conclusion: looks like the Polysorbate 20 is making my solution cloudy. Not sure 1. If this is a problem 2. How to fix it
If anyone has any advice/experience, it’d be appreciated.