Want to make an ampoule, reduce redness, acne, strengthen the skin 1. Centella Asiatica Extract 1-2% 2. Glycerin 10% 3. Panthenol 1%-2 5. Niacinamide 5% 4. Phenoxyethanol 0.5-1.0% 5. Xanthan Gum 1% 6.water Question 1. If you want to get pH 5.5, you should increase/cut. which one? 2. Can this recipe ...
