Formula Feedback

Your formula includes:

• Vitamin C (Liquid AA2G™) 5%: According to the product description for Ascorbyl Glucoside (AA-2G Stabilized Vitamin C), this form of Vitamin C is stable and effective in a narrow pH range of 6.5-6.8.
• Salicylic Acid (BHA) 1%: The product description for Salicylic Acid (BHA) states it is used for exfoliation and acne treatment. For Salicylic Acid to be effective as an exfoliant, it needs to be in a formulation with a low pH, typically around 3-4.
• Light Cream Maker™ 1%: This acts as your emulsifier and thickener. The description says it works in a pH range of 2.5-11, so it is compatible with both high and low pH environments in terms of its own stability, but it doesn't resolve the incompatibility of the active ingredients.
• Propylene Glycol 40%: This is a solvent and humectant. The description confirms its use as a solvent in cosmetics and that it can be used to dissolve ingredients like Salicylic Acid.
• Polysorbate 20 3%: This is a solubilizer/emulsifier.
• Water 50%: The base of your cream.

The fundamental problem is that you cannot have both Ascorbyl Glucoside (AA-2G) stable and effective at pH 6.5-6.8 and Salicylic Acid effective at pH 3-4 in the same product. If you formulate at a low pH for Salicylic Acid, the AA-2G will degrade quickly. If you formulate at a higher pH for AA-2G, the Salicylic Acid will be much less effective for exfoliation and acne treatment.

Mixing Instructions

Given the incompatibility issue, it is not recommended to mix these ingredients together in a single formula as proposed. The resulting product would likely be unstable and ineffective for at least one of the key active ingredients.

Recommendations for a Beginner

• Separate Formulas: As suggested in the conversation you shared, the best approach is to create two separate products:
  • One product for skin whitening using Vitamin C (AA2G) formulated at its optimal pH of 6.5-6.8.
  • A separate product (like a toner or serum) for acne and exfoliation using Salicylic Acid formulated at its optimal low pH (around 3-4).
• pH Measurement: As discussed in the conversation, you should measure the pH of your water phase before combining it with the oil phase (if any) and ideally before adding thickeners that create a gel, as this pH will be the final pH of your product. Use a reliable pH meter for accuracy.
• Ingredient Research: Always research the optimal pH range and compatibility of all your ingredients before creating a formula. This is crucial for the stability, effectiveness, and safety of your product.
• Start Simple: As a beginner, start with simpler formulas that have fewer active ingredients and known compatibilities.