[fareloz]

will this work to moisturize skin?

I don’t think we can give you skincare advice because this is a question to your esthetician.

But we can give you feedback on the formula.

1. You have a lack of water thickener (in original product it is Xanthan Gum). It affects texture and stability.
2. You don’t disclose which preservative you are going to use, so 1% might be too high or too low depending on specific blend.
3. You want to add Vitamin E which is a broad name for several ingredients (Tocopherol Acetate, mixed Tocopherols, Tocopherol). Note that original product uses specifically Tocopherol Acetate to preserve oil, not every Tocopherol-like ingredient can do this.
4. They use different emulsifying blend (Glyceryl Stearate + Stearic Acid + Cetearyl Alcohol and ). You want to use Emulsifying wax NF, which is Cetearyl Alcohol and Polysorbate 60. And on top you want to add Cetyl alcohol. Therefore the final texture will be creamier, while original product is probably waxier/harder (due to Stearic Acid). It is fine if it’s your intention.

[fareloz]

It is another gimmick web site that tries to sell you products by using fear-mongering as marketing. It is obvious when you see “paraben free” badges (no scientific resources will say parabens are bad) and “trusted choice” badges (most likely they take money from manufacturers to assign this badge).

[fareloz]

Also, there is no such thing as “allergy free” skincare, because people are so unique that there are even people, who can develop allergy to plain water. That’s why there is no “allergy free” skincare. Correct term is “hypoallergenic” (which they also use) which mean products that do not contain common strong allergens (like citrus fragrances). But to you as a specific person this means nothing because you might have no allergy to strong allergens, but have an allergy to some regular ingredient like glycerin.

You must realize that all skincare on the market is SAFE. Personal sensitivity is PERSONAL, so the website is no help to you, you have to know your own allergens by tries and errors.

[fareloz]

Are you sure 1,2-Hexandiol is a sole preservative? To me it seems that 1,2-Hexandiol is a preservation booster, but not an actual standalone preservative. It is usually included in addition to more reliable preservatives.

[fareloz]

It depends. Usually yes, you want correct pH before adding the ingredient, because some ingredients might be sensitive (for example Sodium Ascorbyl Phosphate). But some (Niacinamide) are that sensitive to pH, so it can be adjusted later.

I don’t know about Alpha Arbutin, but it is better to be safe - measure and adjust the pH before and after addition (because the ingredient itself can change it)

[fareloz]

If you need a formulation service you can get it in another topic here: https://chemistscorner.com/cosmeticsciencetalk/discussion/formulation-services-needed-get-help-here/

[fareloz]

Allantoin solubility is 0.5% top. You have 40% water, so 0.2% is top.

[fareloz]

We need to know the testing procedure and efficacy criteria to answer the question

[fareloz]

If you need a formulation service - go here: https://chemistscorner.com/cosmeticsciencetalk/discussion/formulation-services-needed-get-help-here/

[fareloz]

Yes, shea butter is known to be notorious for getting grainy:
https://www.reddit.com/r/DIYBeauty/comments/1cid9na/i_think_my_homemade_beard_wax_is_suffering_from/

https://www.reddit.com/r/DIYBeauty/comments/ex7ziz/grainy_shea_butter/

[fareloz]

Niacinamide is water soluble. It won’t dissolve in oils.

[fareloz]

Ascorbic acid will dissolve in water that your skin has.

[fareloz]

HEC is mostly used in personal lubes because it has very slippery feel. Not sure you want it in a face cream. I would suggest switching to Xanthan Gum Soft or even better some synthetic polymer like Sepimax Zen or Aristoflex.

But if we look even deeper to the original intention. You want to make your face cream creamier. Usually we use oil thickeners for this. Cetyl Alcohol is the one who gives this creaminess feel without making the cream heavy,

[fareloz]

Aha… Then I see why cosmetic grade is more expensive. Thnx!

[fareloz]

Sepimax Zen? According to their marketing materials it should tolerant to acids and high glycol content

[fareloz]

Indeed. Acidic pH is good for bacteria that causes cavities, so I would be surprised to find acidic toothpaste

[fareloz]

For us the difference between cosmetic grade and food typically comes down to micro spec- lower for cosmetics than it is for food

Lower micro spec for cosmetics grade means less microbes allowed or more microbes allowed? (sorry, not native English speaker)

[fareloz]

I agree that it is exactly what happened. 5% of Curcylic is 2% of Salicylic Acid. Since pKa is below 3%, SA drops pH very much and the solution is losing the viscosity.

[fareloz]

I heat the SA with propanediol 1:15 ratio and then I mixed it with water

Solubility of SA is affected not only by amount of solubilizer, but other additions too. When you add water you decrease the solubility. When you have pure propanediol - you have very high solubility. When you have water+propanediol mix your solubility of SA in it is different. There is a whole study on how to calculate solubility in a mix of solvents: https://pubmed.ncbi.nlm.nih.gov/16649546/

I wrote an article on reddit on how to formulate SA in DIY based on my experience, commercial products and studies. It also contains few formulas: https://www.reddit.com/r/DIYBeauty/comments/1d22zx8/formulation_guidelines_for_salicylic_acid_2_serum/

pubmed.ncbi.nlm.nih.gov

Solubility prediction of salicylic acid in water-ethanol-propylene glycol mixtures using the Jouyban-Acree model - PubMed

To show the applicability of a solution model, i.e. the Jouyban-Acree model, for predicting the solubility of a solute in ternary solvent systems based on model constants computed using solubility data of the solute in binary solvent systems, the solubility … Continue reading

[fareloz]

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[fareloz]

The original tale about lactate buffer started (I assume) with this paper: https://pubmed.ncbi.nlm.nih.gov/25043489/

But the problem is that Urea is most stable at pH 6.0 and decomposes to ammonia, which is basic. So you need an acidic counterpart to neutralize it. Lactic acid has pKa of 3.8. At pH 5.5-6.0 there is almost none Lactic acid in the buffer to neutralize ammonia in case of pH drift.

The paper is also criticized and its issue is described in this discussion on this forum: https://chemistscorner.com/cosmeticsciencetalk/discussion/urea/

[fareloz]

Yes.

The oils definitely create an occlusion, but this layer is not bulletproof. It will prevent the absorption, but can’t hold it over time. You can experience it if you apply some oily product and then the TO suspension. It will sting over time when it reach the water in your face.

[fareloz]

I suspect “Xanthan Gum Transparent” is another name for Soft grade in your suppliers list.

I assume the reason it bubbles is the very high amount of HEC. The product is just too thick and bubbles can’t get out

• This reply was modified 3 months, 2 weeks ago by  fareloz.

[fareloz]

Xanthan Gum has different grades. You need Xanthan Gum Soft. And definitely not the food grade.

Why do you even want to hydrate HEC? Just put it to oil phase, it gonna hydrate itself during emulsification.

[fareloz]

As I said it doesn’t matter what your base is because you don’t have right equipment to disperse the filters. It is just out of reach for DIY. So I promise your result will be 100% failure no matter what DIY technique you have in mind. And since the reliable testing for SPF costs a lot and burns real persons I would strongly encourage you from doing DIY sunscreen because it will fail, you will loose money and hurt people for nothing.