Alternatives for pH adjustment in L-Ascorbic Acid serum without TEA
Question
I want to formulate a Vitamin C serum similar to Skinceuticals. Can I make it without using TEA (alkaline)? If so, what ingredient can I use instead? I would also like to add more [url=http://www.myskinrecipes.com/shop/whitening-%E0%B8%AA%E0%B8%B2%E0%B8%A3%E0%B9%83%E0%B8%AB%E0%B9%89%E0%B8%9C%E0%B8%B4%E0%B8%A7%E0%B8%8ข%E0%B8%B2%E0%B8%A7/133-vitamin-c-l-ascorbic-acid-ultra-fine-%E0%B8%A7%E0%B8%B4%E0%B8%95%E0%B8%B2%E0%B8%A1%E0%B8%B4%E0%B8%99%E0%B8%8ซ%E0%B8%B5.html:20ehgjy9]Vitamin C[/url:20ehgjy9]. My facial skin tolerates pH 2, similar to Kiehl's products I've used. Thank you.
Answer
Yes, you can omit Triethanolamine (TEA) and use other alkaline ingredients to adjust the pH of your L-Ascorbic Acid serum. The purpose of the alkaline ingredient is to bring the pH into the optimal range for L-Ascorbic Acid stability and skin penetration, typically between 2.5 and 3.5. Since your skin tolerates pH 2, you can aim for a pH in the 2.0-3.5 range.
Alternative alkaline ingredients you can use for pH adjustment include:
- Sodium Hydroxide (NaOH): Use a very dilute solution (e.g., 1-10%) and add dropwise while monitoring the pH.
- Potassium Hydroxide (KOH): Similar to Sodium Hydroxide, use a dilute solution and add carefully.
Always add the alkaline solution slowly and check the pH frequently with a reliable pH meter until you reach your target pH.
Regarding adding more Vitamin C (L-Ascorbic Acid), its solubility in water is limited (around 30-35%). While higher concentrations are possible, concentrations above 15-20% may not significantly improve results and can increase irritation. Ensure the L-Ascorbic Acid is completely dissolved in your formula.
Keep in mind that the overall stability of an L-Ascorbic Acid serum also depends on the complete formulation, including solvents and other antioxidants like Ferulic Acid and Vitamin E, as well as proper packaging.
Related Products Mentioned
Vitamin C (L-ascorbic acid) (Ultra-Fine)
