Toner Formula Review: Cleansing and Exfoliation

This is a good starting point for a toner aimed at cleansing and exfoliation, incorporating several effective ingredients. Let's review each component and suggest potential adjustments for optimal performance.

• Papaya Enzyme (Papain): This provides enzymatic exfoliation, which can be gentler than AHAs/BHAs for some. However, Papain's stability in a liquid formula is sensitive to pH (optimal 5.5-7.0) and heat. Its activity also decreases over time once dissolved in water. For better stability in a toner, you might need to add Disodium EDTA (0.1-0.2%) and consider storing the final product in the refrigerator. Alternatively, Papain is often more stable in powder formulations.
• Encapsulated Salicylic Acid (Liquid, Timed-Release, Wash-Off): Important Note: The description for this specific product indicates it is designed for wash-off products only (like cleansers). For a toner, which is typically left on the skin, you should use a Salicylic Acid product specifically intended for leave-on applications. Using a wash-off type in a leave-on product may not provide the intended benefits or stability.
• Licorice Extract (Licochalcone A 1%): This is an excellent addition for its anti-inflammatory and oil-reducing properties, which can help soothe the skin and manage oiliness, complementing the exfoliating ingredients.
• L-Carnitine: This ingredient gently promotes skin cell turnover, offers moisturization, and helps control sebum production. It works well in a toner format.
• Zinc PCA: Known for its ability to reduce oiliness, support acne healing, and stimulate collagen. It's a great fit for an exfoliating and clarifying toner.
• Mild Preserved Eco™: This provides gentle preservation for the formula.

Suggested Adjustments:

1. Change Salicylic Acid Type: Replace the Wash-Off Encapsulated Salicylic Acid with a Salicylic Acid product designed for leave-on use. Check product descriptions for terms like "Leave-On" or suitability for serums/toners.
2. Consider Papain Stability: If keeping Papain, add 0.1-0.2% Disodium EDTA to help stabilize the enzyme. Be mindful that its activity may still decrease over time in a liquid. Ensure the final pH is within its optimal range (5.5-7.0) if prioritizing Papain activity, though a slightly lower pH might be better for other ingredients.
3. Adjust pH: Aim for a final formula pH between 4.0 and 6.0. This range supports the optimal function and solubility of Zinc PCA, L-Carnitine, Licorice Extract, and most leave-on BHA types. You may need to use a pH adjuster (like citric acid or sodium hydroxide) to reach this range.
4. Water: Using purified or distilled water is correct.

By adjusting the type of Salicylic Acid and considering the stability needs of Papain and the optimal pH range for the other actives, you can create a more effective and stable cleansing and exfoliating toner.