Formulation Advice

1. Night Cream Base/Emulsifier

Your night cream formula contains a significant amount of acidic ingredients and electrolytes, which can be challenging for many pre-made bases and emulsifiers, potentially causing instability or separation.

Instead of relying on a single pre-made base, building the cream from scratch using emulsifiers and thickeners known for their stability in low pH and with electrolytes is recommended.

Suitable options include:

• Carbomer U21: This is a gel maker that works well in a wide pH range (5-11) and is tolerant to electrolytes. It can help build the gel network in the water phase, contributing to the overall stability.
• Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer: This is another thickener that functions without heat, is stable in a wide pH range (3-12), and can handle oils and electrolytes. It's effective for creating stable cream, lotion, or gel textures.
• Ceteareth-25 combined with Cetyl Alcohol: Ceteareth-25 is an O/W emulsifier that helps combine water and oil, providing texture and stability, especially when used with a co-emulsifier like Ceteareth-6 (though Ceteareth-25 alone can work). Cetyl Alcohol is a fatty alcohol that acts as a thickener and emollient, adding body to the cream. While these are common emulsifiers, their stability with your specific high load of acids and electrolytes needs careful testing. Using them in conjunction with acid/electrolyte-tolerant polymers like Carbomer U21 or Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer can enhance stability.

Recommendation: For maximum stability with your complex active blend, consider formulating from scratch using a combination of an acid/electrolyte-tolerant polymer like Carbomer U21 or Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer in the water phase, along with traditional emulsifiers like Ceteareth-25 and thickeners like Cetyl Alcohol in the oil phase, ensuring proper emulsification technique and pH adjustment after adding all ingredients.

2. Day Cream Texture Improvement

Your day cream, using the Moisturizing Lotion Base (Compare to Cetaphil) with added actives, feels sticky, slow to absorb, and leaves a shiny finish. This is likely due to the combination of the base's inherent feel and the added humectants and active ingredients.

To improve the texture and reduce stickiness and shine, you can incorporate ingredients that modify the sensory feel:

• Dimethicone (Very Light/10, Low-Odor): This very light silicone provides a smooth, non-sticky slip on the skin and helps coat the skin without feeling heavy. Adding a small percentage can significantly improve the spreadability and reduce the tacky feel.
• Hemisqualane (C13-15 Alkane): A lightweight, non-greasy emollient that absorbs quickly. It improves skin texture and enhances the spreadability of the formula, helping to counteract the heavy feel.
• Starch Care™ (Maltooligosyl Glucoside): This ingredient offers a "moist but non-sticky" texture and can improve the overall feel of the formulation.

Recommendation: Try adding 1-3% of Dimethicone (Very Light/10, Low-Odor) or Hemisqualane (C13-15 Alkane) to your existing day cream formula. You could also experiment with Starch Care™ at 1-5%. Start with a lower percentage and adjust as needed to achieve the desired feel. These ingredients should help reduce stickiness, improve absorption speed, and minimize the shiny finish.

3. Serum Shininess Reduction

Your serum, based on Nano-TXA™ with added humectants and actives, leaves a shiny finish. Nano-emulsions can sometimes feel slightly occlusive or leave a surface film depending on their composition and the added ingredients.

To reduce the shiny appearance:

• Dimethicone (Very Light/10, Low-Odor): Similar to the day cream, adding a small amount of this light silicone can provide a smoother, less shiny finish by modifying the feel and reducing surface tackiness.
• WaterSil™ 8/12 (Water Gel Detackifier): Although designed for water gels, this blend of silicones is specifically formulated to reduce tackiness and provide a silky-smooth sensation in water-based systems. It might help reduce the perceived tackiness and shine in your nano-emulsion serum.
• Starch Care™ (Maltooligosyl Glucoside): This ingredient can improve texture and offers a non-sticky feel, which could help mitigate the shiny appearance.

Recommendation: Consider adding 0.5-2% of Dimethicone (Very Light/10, Low-Odor) or WaterSil™ 8/12 (Water Gel Detackifier) to your serum formula. Starch Care™ at 1-5% could also be beneficial for texture. Incorporate these ingredients into the water phase or the finished product with gentle mixing.