A Look At Cetyl Alcohol

Hey Patreon, this month we are diving into some more formulating fun, covering Cetyl Alcohol (and Cetearyl Alcohol, but I’ll cover that in the next post). I wanted to take the time to talk about Cetyl Alcohol and its capabilities.

What is Cetyl Alcohol?

Despite the name, Cetyl Alcohol is not the drying, irritating alcohol you might be thinking of, like ethanol or isopropyl alcohol. Instead, it’s a fatty alcohol, derived from vegetable oils or coconut oil, that plays a versatile role in cosmetic formulations. It is a white, waxy solid that melts at a low temperature, making it an easy ingredient to work with in heated formulations.

Let’s dive a little deeper into the concept of HLB (Hydrophilic-Lipophilic Balance), which is crucial for understanding how to properly emulsify ingredients like Cetyl Alcohol into your formulations.

What is HLB?

The HLB system is a way of measuring the balance between the water-loving (hydrophilic) and oil-loving (lipophilic) portions of a molecule. It assigns a numerical value that helps cosmetic chemists determine which emulsifiers to use for different ingredients.

Essentially, the HLB system guides formulators in choosing the right emulsifier to mix oil-soluble and water-soluble ingredients together, creating a stable emulsion. The HLB scale ranges from 0 to 20:

• Low HLB values (0-8) indicate that the ingredient is more oil-soluble (lipophilic). These emulsifiers are better suited for water-in-oil (W/O) emulsions.

• High HLB values (8-20) mean that the ingredient is more water-soluble (hydrophilic) and is better suited for oil-in-water (O/W) emulsions.

Cetyl Alcohol, for instance, has an HLB value of around 15.5, meaning it’s more hydrophilic but requires an emulsifier with the correct HLB value to help mix it into a stable emulsion.

How the HLB System Works

When formulating, you often need to emulsify different oils, butters, or fatty alcohols (like Cetyl Alcohol) into your water phase. Knowing the HLB value of each oil-soluble ingredient helps you calculate the right amount of emulsifier needed to create a stable emulsion. The HLB value of the emulsifier you choose should complement the HLB values of your oil-phase ingredients.

For example, if you want to mix Cetyl Alcohol with water, you’ll need an emulsifier that has an HLB value compatible with Cetyl Alcohol’s HLB of 15.5. This ensures the ingredients blend properly and won’t separate over time.

Why HLB Matters

• Stability: The right HLB value ensures that your emulsion remains stable over time, preventing the ingredients from separating into oil and water layers.

• Texture: Properly balancing HLB values also influences the texture and feel of your product. A well-emulsified lotion or cream will feel smooth and luxurious, while an improperly emulsified product can feel grainy or separate quickly.

• Compatibility: Different oils, butters, and waxes have different HLB values. By knowing these values, you can ensure the ingredients in your formulation are compatible and won’t destabilize the final product.

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Practical Example of HLB in Formulation

Let’s say you’re formulating a lotion with the following ingredients in the oil phase:

• Cetyl Alcohol (HLB 15.5)

• Shea Butter (HLB 7)

• Coconut Oil (HLB 8)

To create a stable emulsion, you’ll need to calculate the required HLB value of your oil phase. Once you’ve done that, you’ll choose an emulsifier (or combination of emulsifiers) that matches or is close to that required HLB value. This will allow you to emulsify the oil-soluble ingredients with water, ensuring your product remains smooth and stable.

Not an Emulsifier!

To clarify, Cetyl Alcohol is not an emulsifier! While it has an important role in formulations, it is classified as oil-soluble ingredient. Just like carrier oils or cosmetic butters, it requires an emulsifier to combine with water and prevent phase separation.

Why is it called an "Alcohol"?

Ever wonder why Cetyl Alcohol is called an “alcohol”? It’s not because it’s like the type of alcohol you find in hand sanitizers or spirits, but rather due to its chemical structure. Look closely at the molecular structure, and you’ll see a hydroxyl group (-OH) at the end of the carbon chain (refer to image at the top of the post). This hydroxyl group is why it’s classified as a fatty alcohol. Despite the “alcohol” in its name, it doesn’t dry out your skin or act as a solvent. Instead, it nourishes, conditions, and enhances the texture of your formulations.

Later in the week we will dive into Cetearyl Alcohol.

I will upload another formulation tomorrow!

Ingredient Shopping

Hello Everyone,

I've put together a shopping list of essential ingredients that you'll find in many of my formulations. This list covers the basics you'll need, along with a few splurge-worthy materials if they fit within your budget. Consider this post your foundational guide—I’ll be updating it every couple of months with new ingredient recommendations for upcoming units as they’re released.

Basic Must-Haves

• Liquid Germall PlusA broad-spectrum preservative is a non-negotiable investment. Liquid Germall Plus is an excellent choice, as it is effective across a wide pH range (3-8), affordable, and readily available. While it isn’t COSMOS-approved, it’s safe within its usage guidelines. If you prefer a COSMOS-approved preservative, consider Germaben II. However, note that COSMOS ingredients generally come with a higher price tag.

• Distilled/Deionized WaterEssential for any water-containing formulations. It’s the foundation of countless cosmetic products.

• Carrier OilsTo avoid overspending, start with a selection of 3-5 versatile oils:

  • Sunflower Oil: Light, quick-absorbing, and cost-effective.

  • Jojoba Oil: A must-have, as it’s unique and difficult to substitute.

  • Sweet Almond, Avocado, or Rice Bran Oil: Choose one of these for additional versatility.

  • Exotic Oils: If budget permits, pick one (e.g., watermelon, argan, rosehip, or blueberry) for added luxury. Keep in mind this is a want not a need.

  I’ll dive deeper into carrier oils in a future post, including my personal experiences and lessons learned.

• Cosmetic ButtersStock up on at least one soft and one hard butter:

  • Refined Shea or Refined Mango Butter: Either can be substituted for the other.

  • Cocoa or Kokum Butter: Again, choose one.

  Tip: Anhydrous products, where butters and oils are used in higher percentages, will be developed in fall and winter. For emulsions, you’ll use smaller quantities, so start with small amounts to keep costs down.

• Vitamin E (Mixed Tocopherols)A vital antioxidant to prevent your formulations from oxidizing. A small bottle will last a long time. Be sure to get the mixed tocopherols version, as it offers the best protection.

• Cetyl AlcoholThis fatty alcohol is a staple for emulsion stabilization, adding body and viscosity to creams and lotions, and improving texture with a velvety feel.

• GlycerinAn affordable and accessible humectant found at every small-scale supplier.

• Propanediol 1,3Another excellent humectant with fantastic skin properties, and without the stickiness.

• Dl-Panthenol (Pro Vitamin B5)Known for its skin and hair benefits, this is a great multi-functional ingredient to have on hand.

• AllantoinAffordable and effective, allantoin is a soothing agent that goes a long way in formulations.

• Siligel or Solagum AX or Aristoflex AVCThese gums are thickeners and rheology modifiers that work well in a variety of formulations. Alternatively, you could choose Aristoflex AVC for a more budget-friendly option. Prenuetralized carbomer,  will work but note that we’ll cover carbomers in-depth in a future unit. I’ll give you a month's notice before that unit, so no need to purchase it just yet. I suggest avoiding carbomers until we have covered them. They are not cut and paste and require knowledge to work with correctly. Although Xanthan Gum is cheaper, it doesn’t perform as well in a wide range of formulas.

• EmulsifiersThis category is vast, and I can’t recommend just one that will work for all formulations. If your budget allows, I suggest purchasing a non-ionic, anionic, and cationic emulsifier to give you flexibility and stability in your creations.

Glyceryl Stearate vs Glyceryl Monostearate

A wonderful Patreon member asked the difference between Glyceryl Stearate and GLyceryl Monostearate. I wanted to give as much information as possible, so I wrote a long-form post for everyone!

Glyceryl Stearate and Glyceryl Monostearate are both emulsifiers commonly used in cosmetic formulations, but they differ in their composition, functionality, and application.

Here's a detailed explanation of the differences:

Glyceryl Stearate

• Composition: Glyceryl Stearate is a mixture of mono-, di-, and triglycerides derived from the esterification of glycerin and stearic acid. The "stearate" portion refers to stearic acid, a saturated fatty acid commonly found in animal fats and plant oils.

• INCI Name: Glyceryl Stearate.

• Functionality: Glyceryl Stearate acts as an emulsifier, helping to blend oil and water components in a formulation. It is also an emollient, providing a smooth and soft feel to the skin. Additionally, it serves as a stabilizer and thickener in emulsions, improving the texture and consistency of products.

• Applications: Glyceryl Stearate is widely used in lotions, creams, sunscreens, and other skincare products. Its ability to provide a creamy texture while maintaining the stability of the formulation makes it a versatile ingredient in both oil-in-water (O/W) and water-in-oil (W/O) emulsions.

• HLB Value: Glyceryl Stearate has a low Hydrophilic-Lipophilic Balance (HLB) value, typically around 3.8-4.2, which makes it more suitable for water-in-oil emulsions. However, it is often combined with other emulsifiers to create stable oil-in-water emulsions as well.

  
  

Glyceryl Monostearate (GMS)

• Composition: Glyceryl Monostearate is specifically the monoglyceride form of glyceryl stearate, meaning it primarily consists of one stearic acid molecule esterified to glycerin. It is more refined and has a higher content of monoesters (usually over 90%) compared to the mixed glycerides in glyceryl stearate.

• INCI Name: Glyceryl Stearate

• Functionality: Glyceryl Monostearate is a more specific emulsifier and thickener, with stronger emulsifying properties than glyceryl stearate due to its higher monoester content. It is also an emollient, imparting a silky feel to the skin. GMS can act as a stabilizer and opacifier, giving formulations a more opaque and uniform appearance.

• Applications: GMS is commonly used in creams, lotions, and ointments, particularly in oil-in-water emulsions. It is also found in food products as an emulsifier and stabilizer.

• HLB Value: The HLB value of Glyceryl Monostearate is higher than that of Glyceryl Stearate, typically around 3.8-4.2 (similar), but in formulations, its more refined nature gives it a stronger emulsifying ability in oil-in-water systems.

  
  

Key Differences

• Composition:

  • Glyceryl Stearate: A mixture of mono-, di-, and triglycerides.

  • Glyceryl Monostearate: Primarily composed of the monoglyceride form (one stearic acid molecule attached to glycerin).

• Functionality:

  • Glyceryl Stearate: Versatile emulsifier and stabilizer, often used in combination with other emulsifiers.

  • Glyceryl Monostearate: More potent emulsifier, especially in oil-in-water emulsions, with stronger thickening and stabilizing properties.

• Application:

  • Glyceryl Stearate: Suitable for a broader range of emulsions, including water-in-oil.

  • Glyceryl Monostearate: Typically used in oil-in-water emulsions for its stronger emulsifying action.

While Glyceryl Stearate and Glyceryl Monostearate share similarities in their roles as emulsifiers, they differ in their chemical composition and functionality. Glyceryl Stearate is a mixture of different glycerides, offering versatility in various types of emulsions, while Glyceryl Monostearate is a more specific and purified form, providing stronger emulsifying and thickening properties, especially in oil-in-water systems. The choice between the two will depend on the specific needs of the formulation, such as the desired texture, stability, and type of emulsion.