Serum Formulation Issues: Texture, Absorption, and Pro Polymer Dissolution with Zinc PCA

Question

I am formulating a serum using Pro Polymer (Gel Maker) and Zinc PCA. The resulting texture is liquid but feels sticky and absorbs slowly, almost like it's just coating the skin. When mixing by hand, the Pro Polymer clumps and doesn't seem to dissolve completely. Does the serum actually absorb into the skin, or does it just coat the surface? What are the techniques for dissolving Pro Polymer (Gel Maker) completely, especially when hand mixing results in clumps? Are the ingredients, particularly the combination of Pro Polymer and Zinc PCA at high concentrations, necessary or compatible, and are they contributing to these texture and dissolution issues?

MySkinRecipes Expert · Accepted Answer

Based on the formulation you've created and the feedback from the staff, here's a summary addressing your questions:

Regarding the texture (liquid yet sticky/slow absorption):
The staff explained that the sticky and slow absorption is a normal characteristic of Pro Polymer™ when used without oils or silicones to improve glide. Additionally, the high concentration of active ingredients in your formula contributes significantly to this sticky feeling.

1. Are the ingredients necessary and can they be used together?
The ingredients you've chosen are generally compatible, but the high total concentration of actives (around 37.5% excluding water) combined with the gelling agent (Pro Polymer™) and the presence of Zinc PCA is contributing to the texture issues you're experiencing. While the combination is possible, the staff noted that Zinc PCA acts as an electrolyte which weakens the gel structure formed by Pro Polymer™ and makes it harder to dissolve. Whether all ingredients are "necessary" depends on your specific skin goals, but the current combination at these percentages is causing the texture problems.

2. Does the serum absorb into the skin, or does it just coat it?
The staff confirmed that the serum will absorb into the skin, but it will take longer than usual due to the formula's characteristics (high active load, Pro Polymer™ texture). They recommend using this formulation specifically at night because of the slow absorption and potential stickiness during the day.

3. Are there techniques for dissolving Pro Polymer™ (Gel Maker)?
Yes, dissolving Pro Polymer™ fully, especially in the presence of electrolytes like Zinc PCA, is difficult with manual mixing and can result in undissolved clumps, which contribute to the sticky feeling. The staff recommends using a mechanical mixer or blender to help ensure the Pro Polymer™ dissolves completely. They also suggested that removing Zinc PCA from the formula would make the mixing process significantly easier and potentially improve the texture. If you remove Zinc PCA, you might only need 1.0% Pro Polymer™ for sufficient thickening.

In summary, your formulation is likely experiencing texture issues due to the high concentration of actives, the nature of Pro Polymer™ without glide enhancers, and the presence of Zinc PCA which interferes with the gelling agent. Using a mechanical mixer can help with dissolution, and removing Zinc PCA could simplify mixing and improve texture. The serum does absorb, but slowly, making it more suitable for nighttime use.