General Questions about Formulating

1. Dissolving ingredients once for two batches: Yes, you can dissolve ingredients for the total amount (e.g., 300g) at once and then divide the dissolved mixture into two equal portions (e.g., 150g each) for subsequent mixing steps. This helps ensure consistency between your two smaller batches, especially when working with scale limitations.
2. Material for heating water and adding Disodium EDTA:
   • For heating water, using glass containers (like beakers) or appropriate grade stainless steel is recommended. These materials are heat resistant and do not react with ingredients. For larger quantities, stainless steel tanks are suitable. Avoid using aluminum.
   • Disodium EDTA can be added to the water phase from the beginning, along with Hydroxyethyl Cellulose. Alternatively, you can add it after the gel has formed, ensuring you mix thoroughly to ensure it dissolves completely.
3. When to add Aloe Vera Extract: You should add Aloe Vera Extract after the gel has formed and the mixture has cooled down. This is because Aloe Vera Extract should not be exposed to excessive heat.
4. Vitamin C in loose powder: You can mix L-ascorbic acid powder into loose powder for skin application, and it will provide some benefits. However, absorption into the skin will not be as effective as when used in water-based formulas, as Vitamin C requires moisture to dissolve and be absorbed. It is recommended to use the Ultra-Fine powder grade to avoid a gritty texture on the skin.
5. Oil-soluble ingredients in natural oil: Yes, oil-soluble ingredients like Vitamin E, Vitamin A (retinyl palmitate / retinol palmitate), and Coenzyme Q10 can be mixed into natural oils and applied directly to the skin. Some powdered oil-soluble ingredients might require gentle heating to dissolve in the oil. Once dissolved, simply mix well. For Centella Asiatica Extract, ensure you are using an oil-soluble version if you intend to mix it directly into oil.

Recommendations for Your Formulas (for Dry Skin)

Overall, the formulas you have designed focus on moisturizing ingredients, which are suitable for dry skin.

• Formula 1 (Water-based, slightly viscous): This formula is suitable for dry skin and will result in a slightly viscous liquid texture as you desire. If you need a bit more viscosity, you can add a small amount of a gel maker like Pro Polymer™.
• Formula 2 (Gel, non-flowing): This formula is also suitable for dry skin and will result in a non-flowing gel texture. If you need it thicker, you can add more Pro Polymer™. Adding Silky Serum Base Plus to an already gelled formula is not necessary, as Silky Serum Base is used to create a base, not to thicken an existing gel.
• Formula 3 (Thick or thin gel): The thickness of the gel will depend on the amount of Hydroxyethyl Cellulose used. However, this formula has important considerations:
  • Using Lactic Acid at 11.36% and Salicylic Acid at 10% is quite high for a leave-on product, especially for dry skin. This can lead to stickiness, a distinct odor from Lactic Acid, and significant skin irritation.
  • Hydroxyethyl Cellulose is stable at pH levels not lower than 3. The high concentration of acids in this formula might lower the pH below 3, causing the gel to lose its structure. You may need to adjust the pH upwards (not lower than 3) using a mild base like Triethanolamine.
  • For dry skin, high concentrations of AHA and BHA can exacerbate dryness and cause irritation. It is recommended to consider reducing the Lactic Acid concentration to 5% initially and perhaps consider Glycolic Acid as an alternative to Lactic Acid, which may be less sticky and have less odor (though still an exfoliant). Always adjust the pH to a suitable range.
• Formula 4 (Liquid gel): This formula will result in a liquid gel texture suitable for a pump bottle. The viscosity will depend on the proportion of Hydroxyethyl Cellulose used. It is suitable for dry skin.
• Formula 5 (Lotion/BB cream texture, water-dropping): This formula uses Water-Capsule™, which creates a Water-in-Oil (W/O) cream. W/O creams provide a light feel but form a protective layer on the skin; they do not typically exhibit the "water-dropping" effect. The water-dropping effect is usually achieved with specific Water-in-Silicone or certain W/O systems, such as those made with Silky Serum Base as previously mentioned by the staff. Adding a gel maker to this W/O formula might alter the texture but is unlikely to create the water-dropping effect and could potentially destabilize the emulsion. For the water-dropping effect, it is recommended to try the Water-in-Silicone formula suggested by the staff using Silky Serum Base.

Hope this guidance is helpful for your skincare making journey!