Proper Usage of BTMS 90% in Cream Formulation

How to Use Behentrimonium Methosulfate (BTMS 90%) in a Face Cream Formulation

Hello, I understand the issues you're encountering when using Behentrimonium Methosulfate (BTMS 90%) in your Moisture Cream formulation. Based on the problems you described, it seems the difficulties arise from how the ingredient is being incorporated into the formula.

BTMS 90% is not simply "water-soluble" in the conventional sense like some other ingredients. It is a Cationic Emulsifier and Conditioning Agent that functions by creating a cream structure (Emulsion) and providing a soft, smooth feel to the skin or hair.

The problems you experienced with each method are due to different reasons:

1. Dissolving directly in the water phase with Carbomer: BTMS 90% is a positively charged ingredient, while Carbomer 940 is a negatively charged gelling agent. When mixed directly in the water phase, they will precipitate or clump together due to the opposing charges neutralizing each other. This prevents proper dissolution or dispersion and interferes with the gelling action of Carbomer. BTMS requires heat and combining with an oil phase to form an emulsion, not just dissolving in cold or warm water like salt or sugar.
2. Dissolving BTMS in water and adding to gelled Carbomer: The issue here is still the incompatibility of charges between BTMS (positive) and Carbomer (negative). Even if BTMS is dissolved with heat, adding it to the negatively charged Carbomer gel will cause clumping and disrupt the gel structure, preventing the cream from thickening when TEA is added.
3. Dissolving BTMS in water with heat and adding to a pre-formed cream: Adding a concentrated ingredient, especially one with potential charge incompatibility, to an already formed cream can destabilize the existing emulsion structure. The cream thinning immediately and separating later indicates that the emulsion was unstable and broke.

The Correct Method for Using BTMS 90% in a Cream Formulation:

BTMS 90% should be used as part of the Oil Phase or Emulsifier Phase in a hot process emulsification. The general steps are as follows:

1. Separate Ingredients: Divide your formula ingredients into two main phases: the Water Phase and the Oil/Emulsifier Phase.
2. Prepare the Oil/Emulsifier Phase: Combine all oil-soluble ingredients, including BTMS 90%, in a heat-resistant container.
3. Prepare the Water Phase: Combine all water-soluble ingredients, including well-dissolving and compatible ingredients (like EDTA, Allantoin, Glycerin), in another heat-resistant container.
4. Heat the Phases: Heat both phases simultaneously. Control the temperature to be suitable for melting BTMS (typically around 60-70°C or as recommended by your supplier). Heat until the ingredients in the oil phase are fully melted and combined, and the water phase is at a similar temperature.
5. Combine the Phases: Slowly pour the Oil/Emulsifier Phase into the Water Phase (or vice versa, depending on the desired emulsion type and specific technique) while stirring or mixing with medium to high speed to facilitate emulsion formation.
6. Continue Mixing: Continue mixing the blend as the temperature gradually decreases. Continuous mixing during the emulsion formation and cooling phase helps achieve a smooth and stable cream texture.
7. Add Heat-Sensitive Ingredients: Once the cream has cooled down to an appropriate temperature (typically below 40°C), add heat-sensitive ingredients such as preservatives, extracts, or fragrance.
8. Adjust pH (if needed): Check and adjust the pH of the cream to a range suitable for face products (typically pH 5.0-6.0). If pH adjustment is necessary, add the adjusting agent gradually while mixing.

Additional Considerations:

• Compatibility with Carbomer: Since BTMS is cationic and Carbomer is anionic, using them together can lead to compatibility issues and a less clear texture. If Carbomer is essential for your formula, you might consider using a very small amount, using a different thickener that is more compatible (such as non-ionic or amphoteric thickeners), or employing more complex formulation techniques to minimize charge issues.
• Temperature: Adequate heating and temperature control during phase combination and cooling are crucial for emulsion stability.
• Mixing: Using appropriate mixing equipment and the correct speed will help achieve a smooth and stable cream texture.

Regarding a video demonstration, you might try searching online resources for videos on making creams or conditioners using Cationic Emulsifiers like BTMS.

I hope this guidance is helpful for your formulation development.