Whitening and Sunscreen Body Lotion (Cold Process, 500ml)

Here is a proposed formula and instructions for a cold-process whitening and sunscreen body lotion (500ml) using the ingredients you provided. This formula aims for noticeable whitening and provides sun protection. Please note that combining multiple potent actives requires careful formulation and patch testing.

Formula (500ml Total)

Ingredient Roles:

• Whitening: Tranexamic Acid, Vitamin C, Phenylethyl Resorcinol, GlucoBright, Safe-B3, and Azelaic Acid work together to target hyperpigmentation and brighten skin tone.
• Sun Protection: SPF Protect Ultra™ III provides broad-spectrum UVA/UVB protection, essential for preventing further darkening and maintaining whitening results.
• Exfoliation: Glycolic Acid helps to gently exfoliate the skin surface, promoting cell turnover for a brighter appearance.
• Soothing & Hydration: Aloe Vera Extract and GlucoBright contribute to skin hydration and can help soothe potential irritation from the actives.
• Emulsifier & Thickener (Cold Process): Satin Cream Maker™ allows the oil and water phases to combine without heat.
• Stabilizer: Disodium EDTA helps improve the stability of the formula, especially for Vitamin C.
• Preservative: Phenoxyethanol prevents microbial growth.

Cold Process Mixing Instructions:

1. In a clean beaker, combine the Water and Disodium EDTA. Stir until the EDTA is fully dissolved.
2. Add Safe-B3™, GlucoBright™, Tranexamic Acid, and Aloe Vera Extract to the water phase. Stir until all powders are completely dissolved and the liquid is uniform.
3. In a separate clean beaker, combine SPF Protect Ultra™ III and Phenylethyl Resorcinol. Stir to mix.
4. Add Satin Cream Maker™ to the water phase (from step 2) and stir until it is well dispersed and the water phase starts to thicken slightly.
5. Slowly pour the oil phase (from step 3) into the water phase (from step 4) while continuously stirring. Continue stirring until a smooth, uniform lotion is formed. Avoid high-speed mixing (keep below 2500 rpm) to prevent damaging the emulsifier.
6. Ensure the lotion temperature is below 30°C. In a very small amount of the total water reserved from step 1, dissolve Vitamin C (L-ascorbic acid). Add this dissolved Vitamin C solution to the main lotion and stir thoroughly until fully incorporated.
7. Ensure the lotion temperature is below 60°C (ideally room temperature for cold process). In a very small amount of the total water reserved from step 1, dissolve Glycolic Acid. Add this dissolved Glycolic Acid solution to the main lotion and stir thoroughly.
8. Ensure the lotion temperature is below 40°C (ideally room temperature). Add Azelaic Acid (Liquid Azelaic™) to the main lotion and stir thoroughly.
9. Add Phenoxyethanol to the lotion and stir until evenly distributed.
10. pH Adjustment: This is a critical step. Measure the pH of the final lotion using a pH meter or pH strips. Due to the acidic ingredients (Vitamin C, Glycolic Acid), the pH will likely be low. Carefully adjust the pH upwards to a target range of 4.0-4.5 using a dilute solution of a pH adjuster (e.g., Triethanolamine solution). Add the pH adjuster drop by drop, stirring well after each addition, and re-measure the pH until the target range is reached. Note: Achieving optimal pH for all actives simultaneously is challenging. A pH of 4.0-4.5 is a compromise to benefit Vitamin C, Glycolic Acid, and Phenylethyl Resorcinol, but is below the optimal range for Azelaic Acid.
11. Once the pH is adjusted and the lotion is uniform, package it in appropriate containers that protect from light and air.

Important Considerations:

• Irritation: This formula contains multiple potent active ingredients at relatively high concentrations. This increases the potential for skin irritation, redness, or peeling, especially for sensitive skin or when first starting use. It is highly recommended to perform a patch test on a small area of skin before applying the lotion to your entire body.
• pH Stability: Maintaining the target pH is crucial for the stability and efficacy of the acidic ingredients. The pH may shift over time, which can affect the product's performance and safety.
• Sun Protection: While this lotion contains sunscreen, consistent and adequate application is necessary to achieve the stated SPF level and protect your skin from UV damage, which causes darkening. Reapply as needed, especially after sweating or washing.
• Storage: Store the finished lotion in a cool, dark place, away from direct sunlight and heat, to help maintain the stability of the active ingredients.

This formula provides a strong combination of whitening and sun protection agents in a cold-process format. Start with a patch test and monitor your skin's reaction. If irritation occurs, reduce the frequency of use or the concentration of some active ingredients.