Formulating a sunscreen lotion with mineral UV filters.
want to make a sunscreen lotion without other actives than the UV filters, for
own use. The SPF will be about 15. The UV filters I use are micron. zinc- and
titanium(di)oxide, coated with simethicone (SofiTix).
I also want to add another, volatile silicone, because of its nice skinfeel. I
know silicones can be tricky, so I hope the stability of the way I formulated
etc will be sufficient. This is the first time I will be working with
My formula, feel free to comment, much appreciated!
E-wax (glyceryl stearate + PEG100 stearate)
sunflower seed oil
6% SofiTix (nano zincoxide/nano
0.3% benzyl alcohol + DHA (Cosgard)
0.1% potassium sorbate
acid in aqua for pH < 5.5
Disperse SofiTix in mixture of sunflower oil + cyclo D5
glycerin, heat to 70C
emulsifiers + petrolatum -> 70C
phase 1 to the 2+3 emulsion in the cooling phase.
preservatives + α-tocopherol.
QUERY: Would 9% oil be enough
to disperse 6% SofiTix?
If so, should I use even less oil in the premix and add oil to phase 3?
Would this be stable enough for the 1% cycloD5 and the simethicone coating?
I wanted to add benzyl alcohol to prevent discoloration by potassium sorbate,
like @DRBOB@VERDIENT.BIZ said. I don’t use it very long, so it probably won’t
Is pH 5.5 low enough for potassium sorbate to ‘metabolize’ into sorbic acid?
Thanks a bunch!