Formulating 2% Salicylic Acid Face Wash for Oily and Acne-Prone Skin

Question

I am trying to make a 2% salicylic acid face wash. I have few doubts related to this:

How much % is enough for a skin like with blackheads, whiteheads, T zone oily area, sebum on nose and chin, milia on forehead/under eye and acne prone skin (only on condition like dehydration/menstruation/more sugar consumption).
Which ingredients is good with salicylic acid: Niacinamide, Allantoin, Sodium PCA, Zinc PCA, Betaine. And in what %? If we can use all of them, then what is the %?
Which thickener is good for skin (PEG-150 distearate, C MEA, HEC, Xanthan gum)? If you have any other suggestions, then tell those. I have used 0.7% HEC and 0.7% Xanthan Gum, but it is giving gel like structure.
What is good solubilizer for Salicylic acid? I have tried to with sodium lauroyl Sarcosinate and it mix well, but I am thinking to replace this surfactant with glucoside. Currently I am using CAPB, Sarcosinate, SMCT. What surfactant is good for skin and in what %.

Answer 1

Creating a 2% Salicylic Acid face wash requires careful selection of solubilizers and thickeners to ensure stability and a pleasant skin feel. Below are the answers to your specific doubts:

(1) Optimal Percentage for Your Skin Type

For a skin profile with blackheads, whiteheads, an oily T-zone, and milia, 2% Active Salicylic Acid is the standard and most effective concentration for wash-off products. It is oil-soluble, allowing it to penetrate deep into pores to dissolve sebum and keratin plugs. For milia, consistent exfoliation with this concentration helps prevent the buildup of trapped keratin.

(2) Compatible Ingredients and Percentages

The ingredients you mentioned are excellent for balancing the potentially drying effects of Salicylic Acid:

Vitamin B3 (Niacinamide): 1–5%. Helps regulate sebum production and strengthens the skin barrier.
Soothing Agent (e.g., Allantoin): 0.1–0.5%. Essential for reducing irritation from the acid.
Amino Acid Complex: Using a pre-blended mix like Natural Make-Up Amino Acids (which contains Sodium PCA, Betaine, and Zinc PCA) at 1–3% is highly effective.
- Zinc PCA is particularly good for your oily T-zone as it suppresses excess oil.
- Sodium PCA and Betaine provide deep hydration to prevent the "dehydration-triggered acne" you mentioned.

(3) Recommended Thickeners

Gums like Xanthan or HEC often create a "snotty" or gel-like texture that doesn't feel like a traditional liquid wash. For a professional, clear, and "short" flow texture, consider:

SugarThick™ (PEG-120 Methyl Glucose Dioleate): Use at 1–3%. It is a high-performance thickener specifically for surfactant systems. It provides a clear, luxurious feel and can even reduce irritation from surfactants.
PEG-150 Distearate: Use at 0.5–1.5%. This is a classic surfactant thickener that provides a smooth, liquid-soap consistency.

(4) Solubilizers and Surfactants

Salicylic Acid powder is notoriously difficult to dissolve in water-based cleansers.

Solubilization: Instead of using pure powder, it is highly recommended to use Encapsulated Salicylic Acid (Liquid, Timed-Release, Wash-Off). It is already liquid and water-soluble, meaning you can add it directly to your water phase without needing harsh solvents. If using powder, you would need a solvent like Ethoxydiglycol or Isopentyldiol.
Surfactant Choice: Replacing Sarcosinate with a glucoside is a great choice for mildness. Decyl Glucoside or Lauryl Glucoside are excellent non-ionic options.
Simplified Base: You can use a pre-blended base like Sulfate Free No-Tear Shampoo Base, which already contains a balanced mix of Cocamidopropyl Betaine (CAPB), Sodium Methyl Oleoyl Taurate, and Glucosides. This ensures high foam and stability while remaining extremely gentle on acne-prone skin.

Suggested Formulation Structure (Conceptual)

Water Phase: Water, Humectants (from Amino Acid Complex), Vitamin B3.
Surfactant Phase: Sulfate Free No-Tear Shampoo Base (25–35%) + Decyl Glucoside (optional for extra mildness).
Active Phase: Encapsulated Salicylic Acid (Wash-Off) (at the rate required for 2% active).
Thickening: Add SugarThick™ at the end to reach your desired viscosity.
pH Adjustment: Ensure the final pH is around 4.5–5.5 for optimal stability and skin compatibility.