Formulation questions for Bakuchiol, Vitamin C Derivative, and other ingredients

Question

I want to mix the following ingredients: Bakuchiol 1%, Dimethyl Isosorbide, Ascorbyl Tetraisopalmitate 5%, Q10 10% Powder Water Soluble, Argan Oil. Can I mix just these? How should I mix them? Is pH adjustment necessary? I have Citric Acid anhydrous. When applying to skin, do I need to leave it for 20 minutes before following with another cream because I see Vitamin C is present?

MySkinRecipes Expert · Accepted Answer

Subject: Regarding your Bakuchiol formulation

Hello,

Thank you for sharing your list of ingredients and questions. Let's address them:

Is the combination okay? How to mix?
Your list includes ingredients that are oil-soluble (Bakuchiol, Ascorbyl Tetraisopalmiate, Argan Oil) and water-soluble (Q10 10% Powder, Citric Acid). To combine these into a stable product, you will need a suitable base (like water, oil, or a cream base) and likely an emulsifier or solubilizer, depending on the type of product you want to make (serum, oil, cream). The list you provided seems to be the active ingredients and solvents, not a complete formulation base. Without knowing the base ingredients and the percentages of all components, it's difficult to give specific mixing instructions or confirm if they will form a stable product as listed.
Is pH adjustment necessary?
pH adjustment with Citric Acid is mainly needed if your formulation contains a water phase and the resulting pH is too high (alkaline) to bring it into a skin-compatible range (typically 4.5-6.5). Ascorbyl Tetraisopalmitate is stable over a wide pH range. Q10 powder (water-soluble) might have specific pH considerations, but a skin-compatible pH is generally suitable. If your formulation is anhydrous (contains no water), pH adjustment is not possible or needed.
Do I need to wait 20 minutes after applying due to Vitamin C?
The advice to wait 20 minutes after applying Vitamin C usually applies to L-Ascorbic Acid, which requires a low pH for efficacy and can sometimes cause irritation. Your listed formulation includes Ascorbyl Tetraisopalmitate, which is an oil-soluble Vitamin C derivative that is stable at neutral pH and is generally non-irritating. Therefore, you do not need to wait 20 minutes after applying a product containing Ascorbyl Tetraisopalmitate. If you are using L-Ascorbic Acid in a separate product, the waiting advice might apply to that specific product, but not because of the formulation you listed here.

To provide more precise guidance on mixing and pH, please share details about the base ingredients you plan to use and the desired final product type (e.g., oil serum, water-based serum, cream).

We hope this helps!