Clear anhydrous alcohol-based water-resistant sunscreen formula

Yes, but the key is not to dissolve SPF Protect Ultra™ III (UVA+UVB) directly into alcohol first. It is oil-soluble, so make a clear oil/ester/volatile-carrier concentrate first, then add that concentrate into an alcohol phase containing the alcohol-soluble film former.

These are prototype starting formulas for clarity, dry feel and water resistance. Final SPF/UVA/water-resistance claims must be tested on the finished formula, because the SPF estimate for 25% SPF Protect Ultra™ III was measured in an oil-in-water emulsion system, not in this alcohol-based spray.

Formula 1: Clear Dry Water-Resistant Sunscreen Spray

Formula 2: Same Base + Vitamins

Why this structure works

• Propylene glycol dicaprylate/dicaprate helps keep the organic UV filters dissolved while maintaining a light sunscreen feel.
• Isododecane improves quick-dry, very light, non-greasy and water-repellent sensory.
• WaterGuard™ Spray should be dissolved in the alcohol phase; it is the main alcohol-soluble film former for water/sweat resistance.
• Silicone Film is added at a low starting level to improve long-wear and waterproof film strength. Too much can increase tackiness or compatibility risk in a high-alcohol spray, so adjust only after testing.
• Formula 2 includes Protec™ OX and Protec™ UV because Vitamin A Palmitate and Perfect-C™ need extra oxidation/light protection. Use opaque or UV-protective packaging for the retinyl palmitate version.

Manufacturing Steps

1. Oil/UV concentrate: Combine SPF Protect Ultra™ III, Propylene glycol dicaprylate/dicaprate and Protec™ OX. Heat only as needed to about 70–80°C with mixing until Protec™ OX is dissolved and the phase is completely clear, then stop heating.
2. Cool below 45–50°C. Add Isododecane and Silicone Film, then mix until uniform and clear. Keep the vessel covered to reduce volatile loss.
3. Alcohol phase: In a separate closed vessel, add Ethyl Alcohol. Slowly sprinkle in WaterGuard™ Spray under strong mixing until fully dissolved and clear.
4. Slowly add the clear oil/UV concentrate into the alcohol/WaterGuard™ phase while mixing. Continue until fully uniform and clear.
5. De-aerate. Filter only if needed through a compatible coarse polishing filter that does not remove UV filters or film former.
6. For Formula 2, add Vitamin A Palmitate, Perfect-C™, Vitamin E and Protec™ UV only after the heated oil phase is below 45–50°C. Minimize heat exposure after adding the vitamins.
7. Fill Formula 2 into opaque or UV-protective packaging with minimal headspace.

Important Checks Before Commercial Use

• Check clarity after 24 hours, 7 days and 1 month at room temperature.
• Check low-temperature clarity at 4–10°C, because high organic-filter systems can haze or crystallize.
• Check 45°C stability, freeze/thaw stability, spray pattern, actuator compatibility and package compatibility.
• Test final SPF, UVA protection/critical wavelength, photostability and water resistance before making SPF, broad-spectrum, sweat-resistant or water-resistant claims.
• Confirm the UV filter regulatory limits in the target market, especially because SPF Protect Ultra™ III contains multiple organic UV filters.
• The formula is high in ethanol, so use closed vessels, good ventilation, grounding and explosion-proof mixing/filling equipment. Keep away from heat and flame.

Because the formula is water-free, no preservative, pH adjustment, EDTA or aqueous neutralizer is needed unless the system is redesigned to contain water.