Improving Sunscreen Sweat Resistance

To address the issue of your sunscreen feeling greasy when you sweat, you can add a film-former to your formula. Film-formers create a thin layer on the skin that helps the product stay in place and improves water and sweat resistance.

Based on your formula which is a water-based emulsion, suitable film-formers that can be dispersed in water include:

• Allianz OPT: This film-former is designed for water and wear resistance in sunscreens and emulsions. It can be added at a rate of 1-5%.
• Comfort Film (Water Base): This provides a comfortable, non-sticky film and is suitable for skincare to improve durability. You can use it at a rate of 5-10% initially and adjust as needed.

Adding either Allianz OPT or Comfort Film (Water Base) to your current formula should help create a more sweat-resistant product and reduce the greasy feeling when you perspire. You may need to experiment with the usage percentage to achieve your desired texture and level of water resistance.

While adding emollients can help with dissolving UV filters, incorporating a film-former is the most direct way to improve sweat resistance and the feel of the product when sweating.