Understanding Your AHA Gel Formulation and Skin Reaction

It sounds like you experienced a significant reaction when using your AHA gel formulation. Based on your description and the helpful reply you received, the burning and oozing were very likely due to the high concentration of AHA (30%) and, crucially, not neutralizing the acid on your skin after application. Your skin was not accustomed to such a high concentration, and the acid continued to work on your skin, causing irritation and damage.

The Role of pH and Neutralization

The pH of an AHA formulation is critical for its effectiveness. Glycolic acid, a common type of AHA, is most effective at a low pH (acidic). However, a very low pH combined with a high concentration can be very irritating, especially if your skin is not used to it or if the acid is not neutralized.

For consumer products, the FDA generally recommends AHA concentrations no higher than 10% with a pH no lower than 3.5. For higher concentrations, like the 30% you used, application should ideally be done under professional supervision, and neutralization is essential.

Neutralization involves raising the pH of the skin after the desired contact time to stop the acid's activity. As suggested, a solution of Sodium Bicarbonate can be used for this purpose. The goal is to bring the skin's pH back to a more neutral level (above 4.5) to halt the exfoliation process and prevent further irritation.

Regarding Your Formulation Percentages

You mentioned using AHA 30%, Pro Polymer, Triethanolamine, and water. While I can provide general information about these ingredients, providing precise percentages for a safe and effective custom formulation requires expert formulation knowledge and testing. Creating cosmetic formulations involves balancing ingredients for stability, texture, efficacy, and safety.

• AHA (Glycolic Acid): You are using a 30% concentration. This is a high concentration typically used for peels, not daily application, and requires careful handling and neutralization.
• Pro Polymer: This acts as your gelling agent. Its typical usage rate is between 0.5% and 5%. The exact amount needed will depend on the desired gel thickness. Higher amounts (above 3%) can create a thicker, pudding-like texture.
• Triethanolamine: This is used to adjust the pH of the formulation by making it more alkaline. Its usage rate is typically between 0.1% and 2.5%. You would add this gradually to your water/AHA/Pro Polymer mixture while monitoring the pH until you reach your target pH. For a 30% AHA solution, the initial pH will be very low, and Triethanolamine will be needed to raise it, although for a peel product, the final pH is still kept acidic (e.g., between 3.0 and 4.0) for effectiveness, followed by post-application neutralization on the skin.
• Water: Purified water makes up the remainder of your formulation.

To formulate your gel, you would typically disperse the Pro Polymer in water, allow it to hydrate and form a gel, then carefully add the AHA. Finally, you would slowly add Triethanolamine while mixing and checking the pH until you reach your desired formulation pH. The percentage of water would be the remaining amount after accounting for the percentages of AHA, Pro Polymer, and Triethanolamine.

Given your experience, it is highly recommended to start with a much lower concentration of AHA if you are applying it yourself and ensure you have a neutralizing solution ready to use after the recommended contact time. Always perform a patch test before applying any new formulation to your entire face.

Key Takeaways

1. Burning was likely due to high AHA concentration and lack of neutralization.
2. Neutralization after using high-concentration AHA is crucial to stop its activity and prevent irritation.
3. The appropriate pH for an AHA formulation depends on the intended use and concentration (lower pH for peels, higher for daily use within FDA guidelines).
4. The appropriate pH on the skin after a high-concentration AHA application is above 4.5 for neutralization.
5. Formulating with specific percentages requires careful consideration and testing; general usage ranges for ingredients like Pro Polymer (0.5-5%) and Triethanolamine (0.1-2.5%) can guide you, with water making up the balance.

Proceed with caution and consider consulting with a skincare professional or experienced formulator for guidance on using high-concentration AHA products safely.