Formulating a Water-Based Roll-On Deodorant with Zinc Oxide

Here are the answers to your questions regarding your water-based roll-on deodorant formula:

1. Ceteareth-20 and Zinc Oxide: Ceteareth-20 is an emulsifier used to help mix oil and water phases. It does not dissolve Zinc Oxide, as Zinc Oxide is a solid particle that needs to be dispersed, not dissolved, in the formula. While Ceteareth-20 might indirectly help with dispersion in an emulsion, it's not the primary or most effective way to incorporate Zinc Oxide into a high-water content formula like a roll-on.

2. Choosing Zinc Oxide: For a deodorant formula where the primary function of Zinc Oxide is its antiseptic properties, Micronized Zinc Oxide powder is generally recommended. Product descriptions indicate that Micronized Zinc Oxide is suitable for deodorant applications. Nano forms, such as Zinc Oxide 35nm Liquid or Zinc Oxide 40nm Dispersion (Water Base), are typically optimized for sunscreen applications to provide UV protection with minimal whiteness.

3. How to Incorporate Zinc Oxide:

   • If using Micronized Zinc Oxide powder or Zinc Oxide (Ultra-Fine, Non-Yellow, Non-Coated, USP) powder, you should disperse it in the water phase of your formula. This is best achieved by adding the powder to the water and using high-speed mixing (like a homogenizer or high-shear mixer) to ensure the particles are evenly dispersed and prevent settling.
   • If using a pre-dispersed liquid form designed for water-based systems, such as Zinc Oxide 40nm Dispersion (Water Base), you can simply add it to the water phase and stir well until uniformly mixed. This is often easier than dispersing powder.

Remember that proper dispersion is key to ensuring the Zinc Oxide is effective and doesn't settle in your roll-on bottle.