Natural Emulsifiers for Cold Process O/W Serum Stability with High Actives
Question
I am having significant issues with dissolving/emulsifying an O/W serum using a cold process. The formulation contains high levels of actives in both the oil and water phases:
- Oil Phase Actives:
- Tocotrienol 2%
- Pure CoQ10 0.5%
- Ascorbyl Tetraisopalmitate 3%
- Water Phase Actives:
- L-Ascorbic Acid 15%
- DMI 10%
- Pentylene Glycol 10%
- 1,2-Hexanediol 5%
I am using basic equipment like a magnetic stirrer, hot plate, and accurate scale. I am looking for a clean, green, and EWG-friendly emulsifier/solubilizer, ideally without involving heat. I have tried Polysorbate 20 and 80, but the oil still separates after a short time.
Is a homogenizer necessary to prevent oil separation and ensure stability in this type of formulation?
Answer
Natural Emulsifiers for Cold Process O/W Serum
Based on your requirement for clean, green, and EWG-friendly emulsifiers suitable for a cold process O/W serum with high oil and water phase actives, here are two natural options that could work:
LeciCream™ (Hydrogenated Lecithin): This is a natural emulsifier derived from Hydrogenated Lecithin. It is described as a cream maker suitable for O/W emulsions. While it's called a "cream maker," it can potentially be used at lower concentrations for a serum texture. It is typically dispersed in the oil phase before combining with the water phase, which is suitable for cold or low-heat processes.
PhosphoMax™ (Modified Phospholipid Emulsifier): This is a 100% natural emulsifier derived from modified Soy Phospholipids. It is highly effective for O/W emulsions and can emulsify up to 20% oil. It also disperses in water and can act as a penetration enhancer. Like LeciCream™, it is added to the oil phase before mixing with the water phase, making it suitable for cold processes. The description notes that when used as a standalone emulsifier, it is recommended to use it with at least 0.3% Xanthan Gum for better stability.
Both options are natural phospholipid-based emulsifiers, which generally align with "clean" and EWG principles. Given the high load of actives in both your oil and water phases, achieving stability in a cold process O/W system without high shear can be challenging.
As discussed previously, using a Homogenizer is highly recommended, and often necessary, to ensure the oil phase is finely dispersed and the emulsion remains stable over time, especially with a high oil load and complex active system like yours. The mechanical shear from a homogenizer helps create smaller, more uniform oil droplets, leading to a more stable product.
Additionally, incorporating a small amount of a thickener or rheology modifier like Xanthan Gum (as suggested for PhosphoMax™) can significantly improve the stability of the emulsion by increasing the viscosity of the continuous phase and preventing droplet coalescence and separation.
Therefore, while these natural emulsifiers are good candidates for your cold process O/W serum, combining them with mechanical homogenization and potentially a thickener like Xanthan Gum will be key to achieving a stable formulation.
