Getting Started with Sunscreen Formulation

It's great that you're interested in learning about cosmetic formulation, especially sunscreen! While the specific forum thread you were looking for might not be available, I can provide some information to help you get started based on available ingredients and bases.

Sunscreen formulations typically involve either chemical filters, physical filters, or a combination of both to protect the skin from UV radiation.

Here are some products that can be useful when formulating sunscreens:

• LipidSoft™ SPF: This is an emollient ester that is excellent for dissolving chemical sunscreen filters without leaving a sticky feel. It can be used in various sunscreen formulations. An example formulation provided in its description includes LipidSoft™ SPF at 10% along with chemical filters like Tinosorb S, Avobenzone, Benzophenone-3, and Octocrylene.
• SPF Protect Ultra™ III (UVA+UVB): This is a blend of chemical sunscreens designed to provide high and broad-spectrum protection against both UVA and UVB rays. It is easy to incorporate into formulas and is not sticky. Usage rates can vary, with 10% providing SPF 20-25, 20% providing SPF 50, and 25% providing SPF 70-100 in an oil-in-water emulsion system. It should be mixed in the oil phase.
• Pure Physical Sunscreen (SPF50+, PA3+, Water-in-Oil, Non-White): If you prefer physical sunscreens, this is a base containing Titanium Dioxide and Zinc Oxide in a water-in-oil system. It has a light texture and offers high SPF 50+ and PA3+ protection. It can be used as a base (90-100%) and customized with other ingredients.
• Clear Sprayable Sunscreen (Super Light, SPF40): This is a clear, liquid sunscreen base that is sprayable and non-sticky, providing SPF 40, PA++. It is suitable for customization by adding other ingredients at a usage rate of 90-100%.

These products can serve as a foundation or key components for developing your own sunscreen formulas. Remember to follow the recommended mixing methods and usage rates for each ingredient.

Formulating sunscreen to achieve a specific SPF and PA level requires testing, but starting with reliable bases and ingredients like these is a good way to begin your journey into cosmetic formulation.