Tag: glycerin

Formulating a lotion: Phase A – THEORY pt.3

LAB NOTES & SAFETY NOTICE
For educational purposes only. Content reflects personal, non-professional formulation experiments and is not instructional.
No formula or information on this site is intended for commercial use, consumer application, or third-party use.
Accessing this content means you accept all risks and full responsibility for safety, testing, legal compliance, and outcomes.
[Full Legal Disclaimer & Safety Requirements]

My Lab Diary: Mastering Phase A (The Foundation)

Hello Hello! 😀 Today I’m looking over my notes on Phase A—the Aqueous Phase. I used to think water was the “easy” part of the cream, but I’ve learned that it’s actually the foundation of everything!

In my experiments, I almost always heat Phase A in a double boiler until it hits 70°C. Why? Because my favorite emulsifiers are “heat-required,” and if Phase A isn’t just as hot as Phase B, the whole thing can “shock” and separate. It’s all about keeping the phases in sync!

1. The Water: Pure or “Poetic”?

I usually keep my water at 70% or more.

  • My Thought: I love the idea of floral hydrosols (like Rose or Orange Blossom), but I’ve noticed they can be quite sensitive to the heat of the double boiler. Lately, I’ve decided to invest my “beaker budget” in high-performance actives instead, using water as my clean, reliable canvas.

2. Glycerin: The Hydration Magnet

Glycerin is a staple in my lab. It’s a humectant, which means it literally “grabs” water molecules and holds them to the skin.

  • Lab Observation: You have to be careful! If I use too much, the cream feels “tacky” or looks too shiny on the face. Sips water. * My Personal “Sweet Spots”:

    • 1.5%: For those days I’m formulating for oily skin.

    • 2.0% – 3.5%: My “Goldilocks” range for normal skin.

    • 4.0% – 5.0%: Only for heavy-duty body lotions!

3. The Gelling Agents (My Stabilizers)

I don’t just use gums for “thickness”—I use them to keep the emulsion from falling apart! Here is what I’ve learned about my favorite polymers:

  • Xanthan Gum: My old reliable! It’s tough and doesn’t care about salts (electrolytes).

    • Pro Tip: To avoid those annoying “fish-eye” lumps, I always mix the gum into the glycerin first before adding the water. Works like a charm! 😀

  • Carbopol® Ultrez 21: I LOVE this one. It makes the most elegant, crystal-clear gels.

    • The “Patience” Method: I just sprinkle it on the water and let it hydrate itself. No stirring!

    • The Bloom: It stays liquid until I add a few drops of Sodium Hydroxide to raise the pH. Then—POOF!—it thickens instantly. I love pairing it with a little Xanthan (0.4% Carbomer / 0.2% Xanthan) for the perfect texture.

  • Hydroxyethylcellulose (HEC): This is my “specialty” gelling agent for when I have lots of salts in a formula.

    • Lab Note: Unlike the others, HEC is a bit of a diva—it needs heat (70°C) to fully wake up and thicken.

Every time I look at these powders, I’m reminded that even the “water phase” is a beautiful science experiment. It’s all in my hands! 😉

HAVE A GREAT DAY! 😄

(Sources)