[michalby]

It’s a preformulated blend of 9:1 phenoxyethanol and ethylhexylglycerin at 0.4%, I oversimplified it in my original formula description, sorry.

[michalby]

I totally agree. Rehydrated plant extract is never going to be the same as a fresh one. And I’m not a fan of either of them :smiley:

The closest you can get to providing your customer a preservative free, shelf stable aloe is to sell the dehydrated juice as a powder, to mix with water or cosmetic products for immediate use. You can pack individual portions in capsules or provide a scoop, maybe add a fancy glass dish for mixing and sell that kind of story 😉

[michalby]

Perry said:

On dehydrating…What would I lose from the Aloe Gel (raw product, right out of the plant) by dehydrating it? 

[…]

When you dehydrate a plant you break down the natural structure of the proteins & other biomolecules. You jumble the polysaccharides & sugars and you evaporate off some of the phenolic compounds. Rehydrating will not bring back any of the evaporated materials. It will also not reform the secondary structures of most of the dehydrated proteins. The sugars will of course absorb the water but there is no guarantee it will reform the structure it had before you dehydrated it.

Think of beef jerky. If you take a steak and dehydrate it, you’ll get beef jerky. But if you put beef jerky in a bowl full of water you aren’t going to get back a steak. It’s nearly identical to what happens when you dehydrate/rehydrate aloe.   

I just want to clear up some things about dehydration. Not always proteins in a dried extract are denatured. A good examples are bromelain proteases and papain. They retain their enzymatic activity so the protein tertiary structure is preserved. A lot of plant proteins of course are sensitive to dehydration and especially heat.

[michalby]

@Abdullah @Pattsi, thanks!

[michalby]

mbach said:

A 1:10 methanol-water solution. It works, but I’m afraid the methanol will interact with potassium chloride and not give me an accurate reading

I can confirm that it is ok to measure pH in methanol solutions, don’t worry about that.

[michalby]

I’ve included just 0.2% of xanthan in my formula, because the difference between 0.2 and 0.3% was unnoticeable (so there’s no point in increasing it). 0.4% although a tiny bit more viscous (still not enough to make the product suitable for a jar) was already slimy and even a bit stringy. I’ll order siligel and try with sclerotium/xanthan combination now.

A pea-sized (~1ml) blob stays on the skin without running or sliding. But scooping it out of the jar is unsatisfactory. Like dipping a finger in apple sauce, just a coating remains and nothing is really being scooped out. It’s meant to be light, just not that light ::wink:

suswang8 said:

[…]

Regarding preservatives, if that is working via your testing, then I am not going to fault it, but I think 0.2% phenoxyethanol is considered quite low.  I assume you are adding in each of these components individually and not adding them as part of a pre-formulated, combined preservative?

This particular formula is not yet tested for microbial contamination after long storage and/or use. But I’ve successfully used that preservative combination before and tests came out fine.

I’ll keep you guys updated.

[michalby]

suswang8 said:

If you’re willing to add Ecogel, I would just as soon add an additional 0.1%-0.2% of gum — either a high-quality xanthan, Solagum, or sclerotium.

And are you sure that’s sufficient preservative?

So a 0.3-0.5% Ecogel plus 0.3-0.4% xanthan? Ok, I’ll try that! Is the ecogel here killing that stringy slimy xanthan skin feel?

Phenoxyethanol (and) Ethylhexylglycerin are at 0.4% (combined), I haven’t had any problems with that amount to date. Do you think it’s necessary to increase it or add another preservative?

Pattsi said:

https://www.neutrogena.com/products/skincare/neutrogena-hydro-boost-water-gel-with-hyaluronic-acid-for-dry-skin/6811047.html

https://www.neutrogena.co.uk/face/moisturisers/hydro-boost-water-gel#ingredients

Yeah, I see the polyacrylamide, carbomer and vinyl dimethicone crosspolymer, I suppose they achieved that smooth gel consistency with a specific combination of these. Neutrogena hydro boost was a reference, along with Clinique Moisture Surge, Laneige Water Bank and Watermelon Glow Sleeping Mask (although it was slimy in my opinion).

[michalby]

Hmm, I’m not sure about increasing the viscosity of the cream with a liquid surfactant such as polisorbate. Ceteareth-20 - fine, but it’s comedogenicity or waxiness might be a problem, I would realy love to keep the skin feel as light as possible.
I forgot to mention that the pH of the cream is 5.5. I haven’t tried carbopol ultrez-30 but I’ve made a batch with a pH of 6.2 and added a regular carbomer (that is viscous at a pH 6-7) it was a bit “crunchy” or “chunky” and it was sliding on a palm a bit like a gel hand sanitizer.

[michalby]

There were some concerns with squalEne (which is naturally present in the skin), or to be more precise the light-induced peroxidation products of squalEne.
SqualAne however is available in its pure form to be applied directly onto the skin. It’s used in high concentrations in salon oil cleanses.