Whitening Agents in Liquid Soap and Shower Oil Formulations

When incorporating whitening agents into wash-off products like liquid soap and shower oil, several factors must be considered, primarily solubility, pH stability, and heat stability during the manufacturing process.

Considerations for Liquid Soap (Water-based)

For water-soluble whitening agents in a general liquid soap formula, the following can be considered:

• GalaWhite™ (Fermented Gallic Acid): This is water-soluble and highly effective. It should be mixed in the last step and heat should be avoided. The optimal pH range for the formula is 5-6. If your liquid soap base has a higher pH, you may need to adjust it to ensure the stability and efficacy of GalaWhite™.
• Safe-B3™ (Vitamin B3, Niacinamide): This is water-soluble and can be mixed into the water phase. It has good heat resistance, but prolonged heating should be avoided. The optimal pH range is 3-8 (best at 4.0-7.0), making it quite versatile for various liquid soap formulations.
• Yeast Radiance™: This is also water-soluble and should be mixed into the water phase, avoiding heat. The formula's pH should be in the range of 4.0-6.5. It functions as a brightener, providing radiant skin without causing irritation.

Considerations for Shower Oil (Oil-based)

For shower oil, which is an oil-based product, water-soluble ingredients like GalaWhite™, Safe-B3™, and Yeast Radiance™ would not be directly compatible without an emulsification system to disperse them in the oil phase.

An excellent option for shower oil is an oil-soluble whitening agent:

• Activated Resorcinol™ (4-Butyl Resorcinol): This ingredient is oil-soluble and can be dissolved in various types of oil. It is highly effective in reducing pigmentation. For wash-off products like soaps, it can be used at a rate of up to 2%. It's important to note that Activated Resorcinol™ is light-sensitive, so the finished product should be protected from light (e.g., in opaque packaging). Avoid using heat during mixing as it can cause deterioration.

General Considerations for Wash-Off Products

Regardless of whether it's liquid soap or shower oil, when using whitening agents in wash-off products (not left on the skin), you should consider:

1. Solubility: Ensure the whitening agent is soluble in the continuous phase of your product (water for liquid soap, oil for shower oil).
2. pH Stability: The pH of the final product is crucial. Each active ingredient has an optimal pH range for stability and efficacy.
3. Heat Stability: Some ingredients are sensitive to heat, which is a common factor during the manufacturing process of soaps and oils.
4. Contact Time: Since these are wash-off products, the contact time with the skin is limited. This means that the effectiveness might be lower compared to leave-on products, or a higher concentration might be needed (within safe limits) to achieve noticeable results.
5. Irritation Potential: Always adhere to recommended usage rates, especially for potent ingredients like Activated Resorcinol™, to prevent skin irritation, even in wash-off applications.

You can find links to all mentioned products below this answer.