Tag: fatty acids

Formulating a lotion: Fatty Acids and ACNE

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These are personal experiments for educational use only— not instructions and not for commercial or consumer use. By proceeding, you assume all risks related to safety, testing, and regulatory compliance.
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Fatty Acid Profiles and Formulation Theory

In the last post I talked about about the GREASE-FALL, which is “how to distribute the fats in order to obtain a specific kind of cream”.
In my formulation research, understanding the specific fatty acid profiles within natural fats is essential for tailoring a formula’s behavior. This is especially true when exploring theory related to blemish-prone skin and how we balance the “Grease Fall.”

The Common Fatty Acids in Cosmetics

The fatty acids found in cosmetic raw materials are categorized by their chemical structure, which dictates how they feel on the skin and their state at room temperature.

  • Saturated Fatty Acids: (e.g., Palmitic, Stearic, Lauric acid). These molecules sit very closely together, making the fats solid at room temperature. In my experiments, a high concentration of Stearic Acid often contributes to the “white-trail” (soaping) effect during application.

  • Monounsaturated Fatty Acids: (e.g., Palmitoleic, Oleic acid).

  • Polyunsaturated Fatty Acids (PUFAs): (e.g., Linoleic/Omega-6, Alpha-linolenic/Omega-3). These have a molecular shape that prevents them from packing tightly, keeping them liquid.

The “Marketing vs. Chemistry” Reality

One of the most important lessons in my journey is that many “exotic” oils share nearly identical fatty acid profiles with much cheaper alternatives.

  • Almond, Macadamia, and Hazelnut oils have very similar compositions despite vastly different price points.

    In my lab, I now cross-reference fatty acid content to ensure the chemistry—not the marketing story—supports the formula.

Theoretical Correlation: Fats and Acne-Prone Skin

Research suggests a correlation between sebum composition and acne: sebum in acne-prone individuals often shows a higher percentage of monounsaturated fatty acids (specifically Oleic acid) relative to polyunsaturated fatty acids.

Theoretical Risks of Oleic Acid:

High levels of Oleic acid are theorized to increase calcium ions ($Ca^{2+}$) on the skin’s surface, which may lead to higher keratinization (clogged pores). This is a critical disparity I consider during formulation design.

Applying the Theory: My “Grease Fall” Strategy

When targeting blemish-prone skin in “theory batches,” I focus on balancing the “grease fall” with high-PUFA oils.

My Experimental Approach:

  1. Butters: Kept at a low percentage (0.5–1%) for consistency without adding excessive heaviness.

  2. Oil Selection: Prioritizing oils low in Oleic acid and rich in Linoleic and Alpha-Linolenic acids.

High-PUFA Oil Reference:

  • Specialty: Hemp, Borage, and Evening Primrose oils.

  • Functional: Grape seed, Raspberry, and Safflower oils.

  • Accessible: Sunflower and Soy oils.

For butters, I look toward Murumuru, Coconut, and Tucuma, as they theoretically contain lower levels of oleic acid compared to traditional heavier butters.

Formulating a lotion: Choosing the fats – THEORY pt.5

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.
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Observations on Lipid Selection & The “Grease-Fall” Theory

The Anatomy of the Oil Phase

In my formulation journey, I’ve found that simply deciding on a total percentage of fats isn’t enough. The true character of a cream depends on how those fats are distributed. I’ve been documenting how different lipid profiles impact the sensory “touch” of an emulsion.

When selecting lipids for a project, I’ve learned to ignore “miraculous” marketing claims and focus purely on technical data:

  • Density: How “heavy” the oil is (e.g., Castor oil at 0.96 vs. Jojoba at 0.86).

  • Spreading Ability: How the oil moves across the skin.

  • Absorption Profile: How the skin feels 10–15 minutes after application.

  • Fatty Acid Composition: (Documented in my separate lipids post).

Note: The data below represents my personal summary and observations. I’ve found that these classifications help me predict the final “vibe” of my experiments.

Technical Observations: Spreading & Absorption

In my lab experiments, I’ve noticed that “Light” oils are often the most deceptive. While they spread fast and seem to disappear, they can often “re-emerge” on the skin surface after a few minutes, leaving a greasy residue if not balanced correctly.

My Reference Scale for Spreading:

  • Very Dense (DD): Wheat Germ (Thick, slow movement).

  • Dense (D): Peanut oil.

  • Medium (MD/M): Olive and Almond oils (Standard “reliable” spread).

  • Fluid (Fl/L): Borage and Sunflower oils (High velocity, fast spread).

My Reference for Absorption (The “After-Feel”):

  • Greasy/Oily: Wheat Germ, Macadamia, Olive.

  • Medium: Argan.

  • High Absorption: Jojoba, Sunflower.

The “Grease-Fall” Rule (Cascading Emollients)

The “Grease-Fall” is the theory I use to balance these different densities. I’ve realized that using only light oils for oily skin, or only heavy butters for dry skin, actually backfires.

  • The Problem with Only Light Oils: The cream spreads too fast and leaves the skin feeling unprotected and eventually oily again.

  • The Problem with Only Heavy Butters: The cream becomes difficult to spread, creates a “white-trail” effect, and feels suffocating rather than hydrating.

The Theory: Every balanced emulsion requires a “cascade”—a mix of all densities to ensure the cream feels good at the moment of application, during the rub-in, and 20 minutes later.

Experimental Case Studies

Case A: Theory for Dry Skin (Target: 12% Fats) In this experiment, I aimed for richness but wanted to maintain spreadability. I modeled the “Grease-Fall” using a Gaussian-style distribution:

  • 1% Beeswax: (High density/Low spread) For protection and “richness.”

  • 6% Butters: (e.g., Shea/Mango) For emollience.

  • 3% Argan Oil: (Medium-Rich).

  • 1% Borage Oil: (Medium).

  • 1% Jojoba Oil: (Very light/High spread).

Case B: Theory for Oily Skin (Target: 5% Fats) Balancing a low-fat cream is harder, but I still try to maintain a professional “cascade”:

  • 2% Jojoba: (Light ester) For the initial “fast” feel.

  • 1.5% Sunflower: (Light) For absorption.

  • 1% Black Currant: (Medium-Light).

  • 0.5% Shea Butter: Even at this tiny amount, I find it helps the cream feel more “complete” and less watery.

Conclusion

This “Grease-Fall” approach is now a standard part of my lab records. By balancing the cascade, the emulsion feels stable and sophisticated. I’ll continue to refine these percentages in my future “Step-by-Step” documentation.