Body Lotion Formulation for Keratosis Pilaris and Dry Skin

The formula you proposed is quite comprehensive for addressing keratosis pilaris (KP) and dry skin. However, to achieve a "lightweight, non-sticky" feel and ensure long-term stability (especially with Urea), some adjustments are recommended.

1. Formula Analysis & Recommendations

• Salicylic Acid Choice: The Liquid Salicylic Acid (Cationic For Wash-Off) you selected is designed for rinse-off products like shampoos or face washes. For a body lotion, it is better to use a leave-on version such as Encapsulated Salicylic Acid (Liquid, Timed-Release) or Complex Salicylic Acid (Powder, Water-Soluble) to reduce irritation and improve efficacy.
• Texture & Stickiness: Your oil phase (Shea Butter 5% + Coconut Oil 10% + Cyclopentasiloxane 5% = 20%) might feel a bit heavy and sticky for a "lightweight" claim.
  • Recommendation: Reduce Shea Butter to 2-3% and Coconut Oil to 5-7%. You can increase Cyclopentasiloxane to 7-10% to improve spreadability and reduce stickiness.
• Urea Stability: Urea is prone to drifting the pH upward over time, which releases ammonia and causes the product to degrade.
  • Recommendation: You already have Triacetin, which helps, but you should also ensure the final pH is buffered. Using Sodium Lactate and a small amount of Lactic Acid (to adjust pH) is a good strategy.
• Water Source: Using hot water from a filter is not recommended for professional-grade skincare. Please use Distilled Water or Deionized (DI) Water to prevent contamination and mineral interference with the emulsifier.
• Fragrance: 2% is quite high for a body lotion and may cause irritation, especially with 10% Urea and BHA. 0.5% - 1% is usually sufficient.

2. Adjusted Formula (100g)

Phase A: Water Phase

1. Distilled Water: (Adjust to reach 100%)
2. Urea (High Purity): 10%
3. Sodium PCA 50%: 2%
4. Sodium Lactate (60% Liquid): 3%
5. Safe-B3™ (Niacinamide): 5%
6. GlucoBright™ (Acetyl Glucosamine): 4%
7. Disodium EDTA: 0.2%
8. Allantoin: 0.3%

Phase B: Oil Phase

9. Shea Butter (Refined): 3%
10. Virgin Coconut Oil: 7%
11. Cyclopentasiloxane: 7%
12. Satin Cream Maker™: 1.5% - 2% (Increase slightly if the lotion is too thin due to high electrolytes)

Phase C: Additives & Preservatives

13. Encapsulated Salicylic Acid (Liquid): 5% (Replaces the wash-off version)
14. Triacetin: 1%
15. Phenoxyethanol: 1%
16. Fragrance: 0.5%

3. Mixing Steps

1. Prepare Phase A: In a beaker, combine Distilled Water (room temperature is fine, no need for hot water) with EDTA, Allantoin, Safe-B3, GlucoBright, Sodium PCA, Sodium Lactate, and Urea. Stir until completely dissolved.
2. Prepare Phase B: In another beaker, combine Shea Butter, Coconut Oil, Cyclopentasiloxane, and Satin Cream Maker™. If the Shea Butter is solid, you may need to gently heat this phase (approx. 50-60°C) until melted and uniform.
3. Emulsification: Slowly pour Phase A into Phase B while stirring continuously with a high-speed mixer (homogenizer or hand blender). The mixture will begin to thicken into a cream/lotion.
4. Add Phase C: Once the emulsion is uniform and the temperature has cooled (below 40°C), add the Salicylic Acid, Triacetin, Phenoxyethanol, and Fragrance. Mix well.
5. pH Adjustment: Measure the pH. It should be between 5.0 - 5.5. If it is higher, use a Lactic Acid solution to drop it down. This range is optimal for Urea stability and BHA effectiveness.

4. Final Result

• Target pH: 5.0 - 5.5.
• Purpose: The 10% Urea and BHA will effectively exfoliate dead skin cells and clear pores (reducing KP), while Sodium PCA and Lactate provide deep hydration. The adjusted oil phase will ensure it absorbs quickly without leaving a greasy film.