Serum Formulation: Mixing for Dropper Texture and Penetration Enhancers

Question

I would like to mix a serum formulation for testing purposes before mass production.

The formulation consists of the following ingredients:

Ectoin 2%
Madecassoside-80 0.5%
Pure-EGCG™ (Green Tea Extract, 98% EGCG) 1%
Palmaria Palmata Extract 5%
Plankton GP4G™ 2%
Copper Peptide 2%
pentylene glycol 3%
Dimethyl Isosorbide (DMI) 3%
Double Hyaluron Liquid 4%
Ethoxydiglycol 2%
Sterile Distilled Water 65%
Repair Activator™ 10%
Xanthan Gum 0.5%

I want to achieve a texture suitable for use with a dropper, similar to The Ordinary serums.

I have two main questions:

What is the correct mixing procedure to achieve this texture? Specifically, should I mix all ingredients in water first before adding Xanthan Gum and blending until it forms a gel, or should I blend water and Xanthan Gum first to form a gel base before adding the other ingredients (1-12) one by one and blending until incorporated?
Regarding the penetration enhancers (pentylene glycol, Dimethyl Isosorbide (DMI), Ethoxydiglycol), is the amount used too high? Should I reduce any of them or use alternative ingredients?

MySkinRecipes Expert · Accepted Answer

Hello,

It's a good idea to test a small batch before scaling up production. Here are instructions on how to mix the ingredients to achieve a serum texture suitable for a dropper, along with comments on the penetration enhancers:

Mixing Instructions:

To get a smooth, gel-like serum texture with Xanthan Gum, it's best to hydrate the gum properly in the water phase. Follow these steps:

Combine the Sterile Distilled Water (65%), Pentylene Glycol (3%), Dimethyl Isosorbide (DMI) (3%), and Ethoxydiglycol (2%) in a container. Mix well.
Slowly add the Xanthan Gum (0.5%) to the liquid mixture while stirring continuously and vigorously. Using a mini-mixer or homogenizer is ideal to prevent clumps, but a whisk or strong stirring can also work. Continue mixing until the Xanthan Gum is fully hydrated and a uniform, smooth gel forms. This process might take 15-30 minutes.
Once the gel base is smooth and lump-free, add the remaining ingredients: Ectoin (2%), Madecassoside-80 (0.5%), Pure-EGCG™ (1%), Palmaria Palmata Extract (5%), Plankton GP4G™ (2%), Copper Peptide (2%), Double Hyaluron Liquid (4%), and Repair Activator™ (10%).
Mix thoroughly until all ingredients are completely dissolved and evenly dispersed in the gel.
Important: Your list does not include a preservative. For any water-based product, adding a suitable broad-spectrum preservative at the recommended usage rate is crucial to prevent microbial growth and ensure product safety and stability. Add the preservative at this stage and mix well.
Optionally, check the final pH of the serum and adjust it to the optimal range for the active ingredients if necessary (often between pH 5-6).

This method of hydrating the Xanthan Gum first will help you achieve the desired smooth texture for a dropper application.

Regarding Penetration Enhancers:

You are using Pentylene Glycol (3%), Dimethyl Isosorbide (DMI) (3%), and Ethoxydiglycol (2%), totaling 8% penetration enhancers/solvents.

Function: These ingredients help dissolve other components and enhance the penetration of active ingredients into the skin.
Amount: The total percentage (8%) is within a common range for serums.
Pentylene Glycol (3%) and Ethoxydiglycol (2%): These are generally well-tolerated solvents and penetration enhancers.
Dimethyl Isosorbide (DMI) (3%): DMI is a very effective penetration enhancer, but at concentrations around 3% or higher, it can sometimes cause a warming sensation, redness, or mild irritation, especially for individuals with sensitive skin.

Whether this amount is "too much" depends on your skin's sensitivity and the desired effect. For your test batch, proceed with these percentages and observe how your skin reacts. If you experience irritation, you might consider reducing the DMI concentration in future batches or exploring alternative solvents/enhancers like Propylene Glycol or Butylene Glycol, although these may affect the texture and skin feel differently.

Remember to store the finished product in a clean, airtight container away from light and heat.

Good luck with your testing!