[Bill_Toge]

+1 for bisulphite

also you may want to consider adding an excited-state quencher, e.g. benzophenone-4 or Tinogard Q, that will keep the concentration of reactive radicals, e.g. oxygen, to a minimum

[Bill_Toge]

water activity is related to the amount of water present, but it’s a function of molecules rather than % w/w; as many cosmetic materials are complicated mixtures with ill-defined molecular weights, the simplest way to gauge it by far is to measure it directly

[Bill_Toge]

another possibility is that the ingredients list is incomplete; the only way to be sure is to examine the product physically

[Bill_Toge]

just out of curiosity, why does it have to be clear?

[Bill_Toge]

yes, that’s definitely a formula

[Bill_Toge]

yes

[Bill_Toge]

cold-pressed shea and cocoa butter often have crystalline components in them, which are removed in refining

if you melt and re-solidify unrefined butters, this can cause them to give the end product a gritty texture, the severity of which is highly variable depending on how quickly they’re cooled

[Bill_Toge]

@mhart123 the fact the coconut oil has figures for arsenic, mercury, lead etc. just means it’s been analysed for those metals; the fact those figures are all less than 0.1 ppm means the oil doesn’t contain arsenic, mercury, lead etc., as 0.1 ppm is the smallest amount that can be detected with that particular method

[Bill_Toge]

bergamot oil works well as a fragrance, but make sure it’s furanocoumarin-free

[Bill_Toge]

it’s much easier to do it as an anhydrous product; this removes many of the complicating factors present in emulsions

a number of manufacturers make hydrophobically coated zinc oxide specifically designed for sunscreens, which is relatively easy to disperse

but yes, it will be very expensive to test

[Bill_Toge]

@Pharma PG-3 palmitate is solid at room temperature, and PG-3/PG-4 oleate are liquids; aside from that there’s no practical difference

[Bill_Toge]

I’ve used Tego Care PBS 6 a lot, always in combination with a low HLB emulsifier; it’s a very versatile and useful tool, since the polyglyceryl-6 behenate in it acts as an anchor, and helps stabilises otherwise difficult emulsions, e.g. large amounts of acid, salt or urea

it’s functionally similar to Arlacel 165 and analogues (glyceryl stearate / PEG-100 stearate) with the bonus of not containing PEG derivatives

for low-viscosity systems, e.g. serums, the low HLB emulsifier was polyglyceryl-4 oleate, and for creams and similar, the low HLB emulsifier was glyceryl stearate (SE or NSE depending on the application)

[Bill_Toge]

ointments are generally water-free and water-resistant, generally they don’t contain preservatives at all

Nguyen said:

By the way, is there a big difference between PEG-40 and normal hydrogenated castor wax in terms of stability and efficiency that you or anyone may share from your experience?

I’ve read somewhere that a byproduct of the PEG-40 hydrogenated castor wax is dioxane, which can cause cancer. If there is not much difference, I would choose the normal one.

Thanks again for your comments.

they are physically very different materials - PEG-40 hydrogenated castor oil is a sticky, lanolin-like paste miscible with water, while hydrogenated castor oil/castor wax is a very hard, hydrophobic wax that can gel oils

PEG derivatives designed for use in personal care or pharmaceuticals contain less than 1 part per million of dioxane, so your exposure to it is minimal to non-existent

[Bill_Toge]

(daily product dosage in grams) x (percentage of raw material) x (ppm of ethylene oxide) ÷ 100 = daily exposure of ethylene oxide in μg

[Bill_Toge]

lauryl glucoside is not an effective emulsifier, you’d be better off removing it

also, an emulsion can’t be W/O if it has a high HLB emulsifier in it; thermodynamics favours O/W by any means possible, and W/O only forms if there’s no possible way for O/W to form, i.e. no high HLB emulsifier

[Bill_Toge]

in my experience, a combination of malleable microcrystalline wax and sucrose acetate isobutyrate makes a passable substitute

[Bill_Toge]

Cafe33 said:

Hi Belassi. I believe UPS in Mexico to be one of the most dishonest companies I have ever dealt with. I will never use UPS again. The drivers also like to pretend like they passed for delivery and will claim nobody was home. We have 24 hour security in the building, so there is ALWAYS someone available to accept any package.

Citylink freight in the UK used to be exactly like this, except they’d claim they were turned away - no wonder they went bust

[Bill_Toge]

Amira said:

@Bill_Toge 
Zinc oxide is active ingredient for its antimicrobial effect and reducing odor. 
If i use citric acid to lower ph, is it still react with zinc oxide? 

zinc ricinoleate (already in the formula) will do that job a lot better

with zinc oxide, the same thing will happen with any acid

[Bill_Toge]

most vegetable oils have negligible (if any) phenol content; they’re more common in essential oils

[Bill_Toge]

oleic acid can aggravate Malassezia growth; surfactants based on C12-24 acids, saturated or unsaturated, generally don’t

also, outside C12-24 they’re not effective surfactants; they’re either too hydrophilic (< C12) or too hydrophobic (> C24) to be active at the oil/water interface

[Bill_Toge]

the zinc oxide is reacting with the acid, which is why you’re needing to use a lot of it - I’d suggest removing the zinc oxide

[Bill_Toge]

could you provide a photo of these pails?

[Bill_Toge]

try using AMP instead of TEA

[Bill_Toge]

it doesn’t help that your xanthan gum is anionic, and Varisoft EQ is cationic

[Bill_Toge]

alternatively, you can create an emulsion with a very polar oil phase and solubilise the salicylic acid that way