[Meemcha]

Look or ask for in-vivo data as that information actually tells you what you can expect from an active. In-vitro and ex-vivo can give you some insight, but in-vivo is what you want. If a material doesn’t have any data supplied, then you either choose to believe the supplier or pick another material. There are some exceptions, usually with common ingredients. For example, no supplier will provide in vivo data for an essential oil, but there are plenty of studies on essential oils for various skin and health concerns, you just need to research.

[Meemcha]

Literally any face wash with mild surfactants, decent amount of superfatting agent and pH 5-6 is more skin friendly than this all-natural pH gazillion thing.

[Meemcha]

Maybe your method is the problem? Try adding guar at the end, before NaCl. Let hydrate, then add salt. You are introducing a lot of water after the gum has been hydrated.

[Meemcha]

I buy deodorants, shower gels, shampoos and sometimes conditioners because I’m too lazy to make them and it wouldn’t be significantly (if at all) cheaper. And sunscreens I buy because I like to leave that to the guys with more zeros in their development budgets. I’m quite fond of the La Roche Posay Shaka Fluid. Now, my face skin is weird and I have to make all the face stuff myself. Among my favorite ingredients are peptides, vit C (been playing with 3-0-ethyl ascorbic acid lately), ceramides and salicylic acid (not in a same product though). 

[Meemcha]

MarkBroussard said:

@raiyana

There is no such thing as “water-soluble salicylic acid”, but there is a product that is a complex of Salicylic Acid and Acacia Sengal Gum from BASF that is readily water soluble, but expensive realtive to SA.

You will need on the order of 30% glycols (Methylpropanediol + Butylene Glycol) to keep the SA from crystallizing.  Add the SA to the Glycols at 70C or so, stir until dissolved, then add to the hot water phase and let it cool down while stirring.

I would ditch the Polysorbate and instead add Cocoamidopropyl Dimethylamine which will help further dissolve the SA and add 1% Sodium Citrate for good measure.

Finally, adjust the final pH of your concoction to 3.5 - 4.0

Although this is not marketed as such, it is effectively an OTC Acne drug product.

I was recently looking into this product and noticed there is no preservative. The pH is 3.2-3.8 and we assume the glycol input is around 30%, but I am wondering if this is really enough for the product to be self preserving. I am a bit of a germophobe and always like to be on the safe side and it’s bugging me if adding a tiny bit of preservative here would be a good precaution measure or simply unnecessary. 

[Meemcha]

suswang8 said:

Hi, @Meemcha.

For some reason, this derivative is still not widely used; thus, very little information about it seems to be available online.

I saw that a couple of websites describe it as water soluble, in which case I would be tempted to just add it at 1pct to start with and test there.  If you are making 50g samples, that is only 0.5g used/wasted.  May I ask where you found that information about dissolving it in the citric acid mixture first?  I can only imagine it is necessary to do that if the pH of this product is so low that the “shock” of it going into water with a pH of c.7 is too much for it to handle? I really don’t know. 

Hey @suswang8,

Thank you for the response! The first time I saw the buffer recommendation is on my supplier’s site. 

But then, while researching, I found it also here. And this Selco brochure says ‘Ethyl Ascorbic Acid can easily be incorporated in cosmetic emulsion and other formulations. It is water soluble. The recommended pH range is 5.0 - 6.0. For better stability and to avoid pH-drift to acidic pH- values the use of 1 % citrate buffer is recommended.’

I wasn’t planning to work around pH, but to play with it in products with pH 5-6. Just trying to understand if and why pH might drift with this material. Either way, I’ll make a few different samples and keep them at 30-35 deg. Celsius for some time and see what happens. I’ll post the results here in case you are curious

[Meemcha]

ngarayeva001 said:

OMG! These prices are shoking! I wish they have a version of this website in English….

Google translate works just fine with these prices . These guys are giving stuff away for free in comparison to the prices I am paying in the EU. Unbelievable! I just e-mailed them. Momma is getting some new toys :smiley:

[Meemcha]

@”Dr Catherine Pratt” that makes perfect sense and I did take it into consider. However, in one of the knock-outs with this formula, I added 1% Polyquaternium 7 preserved with sodium benzoate before any other cool-down phase ingredients and preservatives and it still affected viscosity. And a few days ago I was at the local dm store reading conditioners’ LOIs and saw one containing behentrimonium chloride, cetrimonium chloride and sodium benzoate as the only preservative. It got me even more confused :smiley:

[Meemcha]

@ngarayeva001  Thanks for the suggestions. Will get amodimethicone. Have you tried cyclopentasiloxane&dimethiconol blend? 

@Vnnil I’ve already tried that and had same issues. But anyhow, I will have 
repeat the same tests with DMDMH as the only preservative. And I tried adding keratin alone to an unpreserved sample and was okay at 0.5%, but I did notice change in viscosity at >1%.
I also tried adding only Euxyl before any cool-down phase ingredients and it didn’t affect viscosity. Will post update here how it went with DMDMH.

[Meemcha]

Bill_Toge said:

if you want to use sodium benzoate you’ll need a secondary, non-ionic emulsifier (e.g. ceteareth-20), both for increased electrolyte tolerance and for stability

Switching to DMDM Hydantoin :smiley:

[Meemcha]

Gunther said:

Is that a hair conditioner or a skin cream?

If it’s the former, then why it contains oil, isopropyl myristate, propylene glycol, Sodium phytate and keratin?
They do nothing in a rinse off product, increase cost and may destabilize the product.

Why so much citric acid?

You can try some cetyl + cetostearyl alcohol instead of just plain cetyl, it makes the emulsion more stable, albeit the texture is slightly different.

It’s an attempt to create a sort of 2in1, rinse off detangling conditioner and anti-frizz leave-in product. I did some research on some existing popular similar products and built the ingredient list around them. I was planning to make a version with silicone and compare them.
That is roughly how much CA it took to keep the pH in 4.5-5 range.
Already tried cetyl-cetearyl combo in various ratio and I still find the texture with cetyl only nicer and smoother. But I will try this combo again with EDTA and DMDMH. Thanks Gunther

[Meemcha]

ngarayeva001 said:

It would be much better if you swap those oils to silicones (not 10%, like 3-4)

@ngarayeva001 I am testing both versions, oils vs. silicones and was planning to compare results. Just ordered EDTA and DMDMH, and will continue testing when I get them. I remember reading your posts about your attempt at a hair conditioner/mask. Have you done any formula updates recently?

[Meemcha]

Perry said:

EDTA perhaps

Thought so. Thank you Perry!

[Meemcha]

Perry said:

It’s probably an electrolyte problem. Anionics (sodium benzoate, sodium phytate) and cationics (behentrimonium chloride, cetrimonium chloride) shouldn’t be used together. The problem is easily solved by using DMDM Hydantoin instead of sodium benzoate.

Thank you @Perry! I have been thinking of that, but I decided to give it a try as I am seeing them all the time with BC and CC and was wondering how others overcome this issue. Do you have any suggestions for a suitable chelate here?

[Meemcha]

Perry said:

@MarkBroussard - I see your 66 ingredients and Tata Harper raises you 72!

https://goop.com/beauty/skin/new-tata-harper-serum-elixir-vitae/

OMG 
Next comes a new products with 86 actives for $650 . I’m not sure I’d pay $450 for 30 ml of concentrated fairy dust .

Perry said:

@Meemcha - Cost savings!  

When I worked at my old company we first had a rule that no (claims) ingredient could be used at less than 0.1%. Then we figured out the cost savings of going to 0.01% was like $300,000 a year. So, the new rule was 0.01% minimum. I think by the time I left the minimum was 0.001%. :smiley:

I need a few more decades to wrap my head around this . When the client I mentioned asked the lab which forms of extracts were used, they answered “it doesn’t really matter, we just dump whatever we have in stock”

[Meemcha]

Perry said:

 It’s more efficient to just make a good guess based on the ingredient list than it would be using analytical instruments to get the formula. 

This reminds me, I was recently working on an existing formula modification. A client hired a lab to formulate and manufacture their product. They weren’t happy with the samples, so they sent me the LOI to get a second opinion. There were 66 ingredients out of which 45 were various botanical extracts. My guess was that they probably had them all at around 0.05-0.1% only for the claims. When I told this to them, they got curious and decided to buy the formula from the lab. All 45 extracts were present at 0.00006%. Not in my wildest dreams would I guess this. Bit still, If i were to copy it based on the LOI, I’d go wit my initial assumption of 0.05-0.1 and the end result would probably be similar, only with higher production cost. 

[Meemcha]

It often takes quite some time and money, but it is totally doable as long as LOI is correct. I get reverse engineering requests from clients all the time and I usually decline them. It is interesting how many of them think that reverse engineering should be cheaper than new formula development because “the formula is out there, you JUST have to copy it”. When a client actually said this to me, I actually copied and pasted the LOI and said “done” 😆

[Meemcha]

Pharma said:

Meemcha said:

…May I trouble you for a brief explanation of that 3:1 limit as recommended concentration of Polysorbate 20 is usually up to 10%. What am I missing here?

That’s just a rule of thumbs. In order to be transparent or at least translucent, emulsion droplets have to be in the form of small micelles rather than droplets. Empty polysorbate 20 micelles contain only about 80 surfactant molecules. Essential oil molecules need to be dissolved between the lipophilic tails rather than forming a core as is the case with ‘standard’ emulsions. Else, the droplets become too large and the solution turns milky. That’s why the ratio of EO to surfactant is a lot small than the ratio of oil phase to emulsifier in a common cream/lotion.

Furthermore, larger droplets tend to cream whilst small micelles are small enough to be subject to brownian motion which counteracts/supersedes gravity.

Thank you! After I posted this today, I did a quick test with Ho wood essential oil. Same thing as with Palmarosa, I got a clear solution at 9:1 ratio. But this wasn’t with pure water, I had 20% lavender hydrosol as well. PEG-40 HCO, on the other hand, did a wonderful job at 5:1 ratio. 

Gunther said:

Polysorbate 20 and/or PEG-40 HCO often need 5x the oils weight.
Only about Poly Suga Mulse D9 works fine at 3x.

I regularly use PEG-40 HCO at 4 or 5:1 ratio and works wonderfully. I actually started this PS 20 quest because I am constantly seeing recommendations for 1:1 ratio for solubilization and it tickled me because my experience said differently and I wanted to check if I was missing something. I wasn’t as PEG-40 HCO really beats it in clear products.

[Meemcha]

@Pharma I am currently experimenting with Polysorbate 20 as EO solubilizer in a toner. Just yesterday I did a seris of Knock-out experiments and ended up with only water, Polysorbate 20 and palmarosa essential oil. Even with 6:1 ratio it was still cloudy. I will try and see what happens with other EOs these days. May I trouble you for a brief explanation of that 3:1 limit as recommended concentration of Polysorbate 20 is usually up to 10%. What am I missing here?

[Meemcha]

EVchem said:

@Meemcha we have used it at 18-20% in anhydrous product. Can’t speak much to performance as we didn’t perform any testing, the client just wanted a stable Vitamin C form with hiiigh percentage. it has not discolored in 50C oven  and it has been almost 5 months

Thank you!

[Meemcha]

Belassi said:

We use that Spectrastat at 0.7% and have never had an issue, even with pea proteins and high aloe vera content. Also should include EDTA at 0.2%.

Thank you!

@MarkBroussard @Pharma @ngarayeva001 have you ever used/seen tetrahexyldecyl ascorbate being used at concentrations above 10%?

[Meemcha]

MarkBroussard said:

Yes, Phenethyl Alcohol would work well in this type of formula

Will look into it. Thank you! 

Speaking of vit C, what are you thoughts on Tetrahexyldecyl ascorbate?

[Meemcha]

Thank you all for the comments! 

MarkBroussard said:

I recently tried it in a formula and found it to be weak on yeast/mold, so I would not recommend it as a stand alone preservative.  Couple it up with a fungicide + chelating agent and you should be in good shape.

You find Spectrastat or Eco weak on mould? I am using a chelator already. Any suggestions on a fungicide?

Perry said:

As an aside, I wish instead of “green formulating” people practiced “safe formulating”

I couldn’t agree more. There is a trend I am seeing on the local market where there is a bunch of vitamin C serums containing MAP or SAP preserved with pottasium sorbate and sodium benzoate. It was frustrating at the beginning, but now it’s just scary. I find it very hard to understand this trending preservative-free frenzy. 

[Meemcha]

Which synthetic surfactants have negative effects on human health and what are those effects exactly? And how does potassium olivate with its pH not have negative effects on health of the skin?