Face serum formula

Blue_LavanderBlue_Lavander Member
edited September 4 in Formulating
Hi, beautiful community! Thank you for accepting me on your forum!
I do not have studies in the cosmetic or chemistry field, and all my formulations that i do for my own use are made after intensive research and reading many articles about the indredients, their properties and safety.
I would like to know your opinion about the following vitamin c serum formula. My questions are:
1. I know that i am theoretically in the safe range of ingredients concentration, but do you think that 10% Polysorbate 80 and 20% Propylene Glycol are too much for a leave on product, used on the face? I needed 10% Poly80 in order for my serum to look clear.
2. Does my formula need a chelator agent? (sodium phytate)
3. I would appreciate your thoughts about the formula, what is your opinion? Mistakes? Do you think i can use it on my face and also get the most loved benefits of Vitamin C?

The serum is kept in the fridge.
The pH, i hope is getting closer to 3.... I wanted to be 3, but i cant know exactly because my pH meter will arrive next month. I lowered the pH with Lactic Acid, and i tested it with stripes, also i compared it with fresh lemon juice which i know is even more acidic....

The formula:

52.88% Distilled Water
15% L Ascorbic Acid
20% Propylene Glycol UPS
0.52% Ferulic Acid
1% Tocopherol (min 50% mix)
10% Polysorbate 80
0.6% Cosgard (benzyl alcohol, salicylic acid, glycerin, sorbic acid)

Thank you!
( Sorry for my speaking mistakes but english is not my mother language).


  • @Blue_Lavander A chelator not only traps unwanted metal ions, but it also improves the performance of preservatives, so yes, I'd recommend adding one. I believe your vitamins are way too high, especially the ascorbic acid. Propylene glycol is also definitely high, considering also that it's not only an penetration enhancerm but also a known allergen beyond 4-5%. Polysorbate is also high, and I'd check first what is it that's causing the loss of clarity (maybe even the very low pH could contribute, and actually, it's lower than the skin pH which is roughly in between 4.5-5.5...reducing the amount of Tocopherol could also help). 
  • @Blue_Lavander Go through L’Oreal’s patent for C E Ferulic. I believe you don’t have enough glycols to stabilise LAA. 

    @ketchito, there’s nothing wrong with 15% of LAA. Some researches suggest 20% is an optimal amount.

  • ngarayeva001 you're right! I'm familiar with formulas up to 10% of LAA, but I believe I was outdated with that info, since I found some studies with higher doses. Good to know, thanks  :)
  • Blue_LavanderBlue_Lavander Member
    edited September 7
    Hello! Thank you for your replies! I appreciate them so much!

    I will try to explain a bit why i did what i did. Might not be the right decisions (due to lack of background in chemistry), but i am experimenting and learning :)....

    The reason why I chose to use 20% PG is because i know that above that concentration, in an aqueous solution doesnt support bacterial growth, so is contributing to the preservation of the formula. Secondly, i needed to disolve the Ferulic Acid in. Also i thought that maybe will help Vitamin C to penetrate into the skin. I red that it can be used in cosmetics/drugs at an even higher concentration, and that not everybody is allergic or irritated by it. I tried it on my face and i didnt have any reaction, but yes, maybe is too high the concentration and in time can cause problems for the skin...

    Before using Poly80 in the final product, i did separate tests, mixing oil with Poly 80 and distilled water at different ratios. The clarity of the solution wasnt influenced by the pH.
    So first I reached clarity at 10% with distilled water, and i kept same ratio for the final product that has acidic pH, and the clarity remained the same.
    Again...if is too much 10%, probably i should find a better solubilizer... Or to repeat the tests.

    I chose 15% LAA, because i red that it is efficient above 8-10% and over 20% can be irritating, so i thought that is better to stay in the middle.

    Ngarayeva001, I looked over the L'Oreal's patent, and i understood what you ment when you said that i need more glycols.... Problem is, that i barely found PG where i live. If i want for example Ethoxydiglycol, i have to order from another country (and probably i will). Another reason why i used PG that much. 

  • Hello,

    hopefully my contribution will help little bit. 
    About the pH - I think pH 3 is nearly self-preserving. Plus you have added preservative, so I think the high amount of PG is not really necessary. 

    15% LAC is great, I'm using 20% myself. Although, some ppl may experience irritation, so starting with lower is better - Timeless Vit. C serum is 20% + E + Ferulic acid .. they say it may arrive cloudy, but it will turn clear over time. Check maybe their ingredient list and compare? :) 

    Happy Formulating!
  • Blue_LavanderBlue_Lavander Member
    edited September 11
    thank you for the reply, Paprik!

    I knew the Timeless ingredients list, and from their order, yeah...they used less Polly 80 than me... Maybe 1:1 with Vitamin E...
    When i did that, the solution became milky and while resting, tiny oil dropplets gathered on the surface. Still milky until today, after more than one week. The same with the sample of 1:4 (vitamin e, polly80), with the difference that with this ratio, the oil doesnt separate.
    Maybe i had to use just 4% of Polly80, even if the solution will stay milky 🤔

    I am using many other actives on my skin, inclusive tretinoin, so i didnt want to start directly with 20% vitamin c. 
    By the way, this serum that i did is not stinging my face at all, and after 10 days is still clear like in the begining. No sign of oxidation 😁.

    Here a picture with samples of Vitamine E and Polly 80 in different ratios (after 10 days).
    Ratios: 1:4, 1:10, 1:1

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