Members Directory - Chemists Corner

Forum Replies Created

LabGuy

Professional Chemist / Formulator
April 17, 2024 at 9:20 am in reply to: Deodorant stick dries slowly on skin

Too much propylene glycol, try reducing it.
LabGuy

Professional Chemist / Formulator
April 12, 2024 at 3:19 pm in reply to: 20% Zinc Oxide for SPF 50?

Wow, that’s impressive.

My guess is that maybe they’re using Zinc Oxides of different sizes (it helps to balance SPF/PFA and achieve broad spectrum protection). Also, maybe there’s soothing ingredients in the formula that prevents erythema. During testing, this can help to boost the SPF value.
LabGuy

Professional Chemist / Formulator
April 9, 2024 at 7:27 am in reply to: Water based stick shrinking

Thanks Matt!

I already did a version with 30% Propanediol. Had to reduce Sodium Stearate also, cause as I increased the glycol concentration, the stick got harder. Now I’ll let it at 45ºC to see how it goes 🙂

Why would you suggest cutting back glycerin though?