Choosing your Emulsifer step by step

Choosing an Emulsifier: 17 Key Considerations for Formulators

Choosing the "best" emulsifier for a cosmetic product is rarely straightforward; it depends heavily on your unique formulation, concept, and ingredients. There's no one-size-fits-all solution, but by considering several key factors, you can make informed decisions. Formula Botanica offers a comprehensive 17-point checklist to guide formulators through this complex process.

The 17-Point Emulsifier Checklist:

1. Natural vs. Synthetic: Define what "natural" means to you, as there's no universal definition. Be aware that even "natural" emulsifiers like lecithin or olive-oil derivatives undergo processing. Avoid synthetic options like PEG or PPG derivatives if aiming for natural formulations.

2. Certified or Not Certified: Decide if organic certification is important for your product and market. Not all natural emulsifiers are certified due to cost, but it's crucial if your final product will be certified. If you also need your formulations or brand to Adhere to Ecocert or Natura let Cosmetic Scientist know this at the start of the formulation.

3. Global Acceptance: Consider market-specific criteria such as vegan, halal, or kosher certifications if selling internationally.

4. Palm Oil Considerations: If avoiding palm oil or committed to sustainable sourcing, scrutinize datasheets and question suppliers about ingredient origins, as many plant-based ingredients (e.g., Cetyl Alcohol) can be palm-derived.

5. HLB (Hydrophilic-Lipophilic Balance): While historically significant, the HLB system is less relevant for modern, natural, PEG-free emulsifiers and plant-oil-based formulations. Instead, focus on whether the emulsifier is for Water-in-Oil (W/O) or Oil-in-Water (O/W) emulsions.

6. Optimum Oil Phase Concentration: Emulsifiers perform best within specific oil concentration ranges (e.g., low, medium, or high oil phases). Match the emulsifier to your desired oil percentage.

7. Viscosity Range: Ensure the emulsifier is suitable for your desired product consistency, whether a thick cream or a light sprayable emulsion, even if you plan to use other viscosity modifiers.

8. Need for Stabilizer/Co-emulsifier: Some emulsifiers require additional stabilizers or co-emulsifiers to perform optimally, especially with alcohol or for specific viscosities. Consider the cost and compatibility with your natural formulation goals.

9. Electrical Charge: Most modern emulsifiers are neutral, but some are ionic (anionic or cationic) and may be incompatible with ingredients of opposing charges (e.g., anionic with cationic surfactants).

10. Best Working pH Range: Emulsifiers have optimal pH ranges; deviating from this can cause instability. This is especially important when considering your preservative system's ideal pH.

11. Electrolyte Tolerance: While rare in most emulsions, if your formulation contains high salt concentrations (e.g., antiperspirants), check the emulsifier's tolerance to electrolytes.

12. Alcohol Tolerance: If your formulation includes alcohol, verify the emulsifier's ability to remain stable in its presence.

13. Oil Phase Character: Different emulsifiers work best with specific types of lipids (e.g., plant oils, waxes, fatty alcohols). Choose one that complements the exact composition of your oil phase.

14. Cold vs. Hot Process: Consider if your ingredients are heat-sensitive. Some liquid emulsifiers allow for cold processing, saving time and energy, but solid ingredients will still require melting.

15. Manufacturing Procedure: Always refer to the manufacturer's guidelines for phase addition (oil to water or vice-versa), but don't shy away from experimenting with reverse approaches, as they can sometimes yield better results.

16. Shear Tolerance: An often-overlooked factor, some emulsifiers require high-shear mixing (e.g., with a homogenizer) for optimal performance, while others are sensitive to it. Inquire with suppliers about manufacturing guidelines.

17. Application Dosage: Emulsifier usage typically ranges around 20% of the oil phase, but can vary. Factor this into your cost calculations and consider co-emulsifiers or stabilizers to potentially reduce the required amount.

Ultimately, successful cosmetic formulation with emulsifiers involves continuous learning, trial and error, and meticulous attention to detail. Always perform thorough testing when making changes to ensure product stability and quality. For those looking to dive deeper, Cosmetic Scientist offers specialised Formulation, Cosmetic Regulation and Small Scale Manufacturing. Call us on 0207 6327557 or contact us https://cosmeticscientist.com/contact