Night Cream Formulation Advice for Oily, Dull, Mature Skin

It's great that you're formulating a night cream tailored to your skin concerns! The ingredients you've chosen are excellent for addressing signs of aging, dullness, and uneven skin tone.

Here's a look at the ingredients you plan to use and some suggestions:

• Vitamin B3 (Niacinamide): At 4%, this is a good concentration for brightening, reducing oiliness, improving skin barrier function, and providing anti-inflammatory benefits.
• N-Acetyl Glucosamine: 4% is also a good level. It works synergistically with Niacinamide for enhanced brightening and helps with gentle exfoliation and hydration by boosting hyaluronic acid production.
• DMAE: You proposed 10%. While DMAE is effective for skin tightening, 10% is a very high concentration and can cause significant irritation, especially for those new to the ingredient or with sensitive skin. It can also feel quite sticky at higher percentages. I recommend starting with a lower concentration, perhaps 3-5%, to see how your skin tolerates it. You can gradually increase the percentage in future batches if needed and if your skin shows no irritation.
• Vitamin B5 (Panthenol): You proposed 5%. Panthenol is a great humectant and soothes the skin. However, at 5%, it can make the product feel sticky or "gooey," which might not be ideal for oily skin. A concentration of 1-3% is often sufficient for its benefits without affecting texture negatively.
• Allantoin: This is a wonderful ingredient for soothing and reducing irritation, which is particularly helpful when using actives like DMAE. The typical usage rate is around 0.5% because it has limited solubility in water at room temperature. If you plan to use more, you might need to heat the water phase or use a solubilizer like Natural Betaine.

Additional Ingredient Suggestions:

To further enhance your night cream for oily, dull, mature skin, consider adding ingredients that target firmness, provide antioxidant protection, and offer lightweight hydration:

• Peptides: Ingredients like Matrixyl 3000 or Matrixyl Synthe'6 can work alongside DMAE to support collagen production and improve skin firmness and elasticity.
• Vitamin C Derivative: A stable form such as Ascorbyl Glucoside or Sodium Ascorbyl Phosphate can boost brightening, provide antioxidant benefits, and help with collagen synthesis without being heavy on oily skin.
• Hyaluronic Acid: Adding a low concentration of Hyaluronic Acid provides excellent hydration without adding oiliness, helping to keep the skin plump and smooth.
• Soothing Agents: Since you are using DMAE, adding extra soothing ingredients like Bisabolol or Centella Asiatica extract can help minimize potential irritation.

Mixing Instructions:

The exact mixing method depends on your base (if using a pre-made one) or your full formula (if making from scratch). However, here are general steps for incorporating these ingredients into a cream or lotion:

1. Water Phase: Dissolve your water-soluble ingredients (Niacinamide, N-Acetyl Glucosamine, Panthenol, Allantoin) in the water portion of your formula. If using Allantoin above 0.5%, you may need to gently heat this phase to help it dissolve completely.
2. Combine Phases: If making an emulsion from scratch, combine your heated water phase and heated oil phase (if any) and emulsify according to your emulsifier's instructions. If adding to a base, simply mix the dissolved water-soluble ingredients into the base.
3. Cool-Down Phase: Once the mixture has cooled to below 40°C, add heat-sensitive ingredients. This is when you would add DMAE, any peptides, Vitamin C derivatives, hyaluronic acid solution, soothing extracts, and your preservative.
4. Mix Thoroughly: Ensure all ingredients are fully dispersed and the mixture is homogenous.
5. Adjust pH: Check and adjust the final pH of your cream to be in the range of 5.0-6.0, which is generally optimal for skin health and the stability/efficacy of most ingredients.

Batch Size:

For your first attempt, starting with a small batch of 50 grams is highly recommended. This allows you to test the formulation, texture, and skin reaction without wasting a large amount of ingredients if adjustments are needed.

Remember to always use precise measurements (preferably by weight) and maintain good hygiene when making your own cosmetics.