Best emulsifier for low pH moisturizers? BTMS vs Lotionpro 165, Montanov 68, Ewax or?
Looking to make a sleek pH 3.8 moisturizing lotion with 10% glycolic acid, used Polawax aka Emulsifying wax NF in the past, but find it too waxy.
Some commonly used emulsifiers are (with prices from lotioncrafter for comparison):
Lotionpro™ 165 $6/lb (Glyceryl Stearate, PEG 100 Stearate) must be thickened with e.g. cetyl alcohol, creates sleeker emulsions than Emulsifying wax. Very common due to its low cost.
BTMS-25 $20/lb also just called BTMS (Behentrimonium Methosulfate, Cetearyl Alcohol) cationic emulsifier, can create very thin and glidy emulsions that leaves the skin feeling moist presumably due to it sticking to the skin, often thickened/stabilized with cetyl alcohol.
Montanov 68 $30/lb (Cetearyl Alcohol, Cetearyl Glucoside) liquid crystal emulsifier, potential issue with ocular irritation due to the glucoside? Expensive and don’t see any clear advantages, similar feel to Lotionpro.
Emulsifying Wax NF $8/lb ( Cetearyl Alcohol, Polysorbate 60) waxier than Lotionpro 165 due to the longer C18 stearyl alcohols, doesn’t need a thickener - not a great choice for lotions.
To me BTMS-25 gives the best skin feel of the bunch, any reason not to use it over Lotionpro 165 apart from the higher cost? I find with Lotionpro you’ll need some added silicones or other film formers to get similar glide and skin feel. Does the BTMS also act as a humectant actually improving moisturization and not only moisturization-feel?