Formulation Advice for Vitamin C Serum

Based on your formula (Silicone 60%, Isododecane 25%, L-Ascorbic Acid 15%), here is some advice regarding adding ingredients for nourishment and improving texture:

Adding Vitamins or Oil-based Ingredients

Yes, you can add other oil-based vitamins or nourishing oils to this formula. Your current formula is primarily oil/silicone-based, which is suitable for oil-soluble ingredients. Examples of oil-soluble ingredients you could consider adding for skin nourishment include:

• Vitamin E (Tocopheryl Acetate): An oil-soluble antioxidant that can provide skin benefits and help protect the formula.
• Jojoba Oil: An oil similar in structure to skin's natural sebum, providing moisture without feeling greasy.
• Squalane (Olive): A highly compatible emollient that moisturizes and improves skin suppleness.

Important Consideration: Since L-Ascorbic Acid is highly unstable in water, you should avoid adding any water-based ingredients or water-soluble vitamins to this formula.

If you add significant amounts of other oils, you might need to include a suitable emulsifier or coupling agent designed for oil-in-silicone or silicone-in-oil systems to ensure the formula remains stable and well-mixed.

Reducing Stickiness and Improving Skin Feel

The sticky or heavy feeling you experience could be partly due to the high concentration of Isododecane. To reduce the stickiness and make the serum feel lighter and absorb faster, you can consider the following:

1. Reduce Isododecane: Lowering the percentage of Isododecane in the formula is the primary way to reduce its inherent stickiness.
2. Replace with Lighter Feel Ingredients: Replace part of the Isododecane with ingredients known for a lighter, drier, or silkier feel. Options include:
   • Lighter Silicones: Such as lower viscosity Dimethicone (e.g., Dimethicone (Very Light/5, Low-Odor)) or Cyclopentasiloxane (a common volatile silicone base, similar to your current formula type, though alternatives like LipidSoft™ Cyclo are also available).
   • Silicone Gels: Products like Silicone Gel (Ultra Clear, Super Silky) can improve spreadability and provide a smooth, silky feel.
   • Skin Feel Enhancers: Ingredients like UltraBlur™ (Skin Blurring Silica) can help absorb some oiliness and provide a smoother, more matte finish.

By adjusting the ratio of Isododecane and incorporating ingredients that offer a lighter skin feel, you can significantly improve the texture and absorption of your Vitamin C serum, making it more pleasant to use and potentially eliminating the need for a separate moisturizer step.