AHA Body Serum Formulation Advice

Based on your proposed formula and the expert feedback, here's a review and suggested adjustments for your AHA body serum aiming for fast exfoliation without dryness or irritation:

Review of Your Original Formula:

1. AHA 10% (Lactic Acid): Good concentration for exfoliation. Effectiveness depends on pH.
2. Sodium Lactate 3-5%: Useful for pH adjustment and hydration.
3. Urea 15%: Should be removed. High concentration Urea works best in neutral pH formulas, not low pH AHA formulas.
4. Allantoin: Good choice for soothing and reducing irritation. Compatible with low pH.
5. Bisabolol (Chamomile Extract): Should be removed. It is oil-soluble and will not dissolve in a water-based serum.
6. Water: The base.
7. Hyaluronic Acid 0.5% & 8. Hyaluronic Acid nano 0.5%: Good for hydration and can help create a serum texture. Compatible with pH 4.0.

Answers to Your Questions:

• 4.) with 5.) Which one should I choose? Choose Allantoin. Bisabolol is not suitable for this water-based formula.
• Should anything be removed? Is this formula too strong? Yes, remove Urea (15%) and Bisabolol. The formula with 10% Lactic Acid is moderately strong. Its potential for irritation is managed by the final pH (aim for 3.5-4.0) and the inclusion of soothing ingredients like Allantoin and Panthenol.
• Can I mix HA first, then add the rest? The recommended mixing order is to mix Lactic Acid with water first, then adjust the pH using Sodium Lactate. You can dissolve water-soluble ingredients like Allantoin, Panthenol, and Hyaluronic Acids in the water phase before adding the Lactic Acid, or add them after the pH adjustment. The key is adjusting the pH after adding the acid.

Suggested Revised Formula & Mixing Steps:

Based on the expert advice, here is a refined formula suggestion:

• Lactic Acid (90% concentration) 10%
• Sodium Lactate (60% liquid) (Adjust amount to reach pH 3.5-4.0, likely around 2-3%)
• Allantoin 0.5%
• Panthenol (Vitamin B5) 5% (Highly recommended for soothing)
• Hyaluronic Acid (Standard Molecule) 0.5-1% (For texture and hydration)
• Hyaluronic Acid (Nano Molecule) 0.5% (Optional, for deeper hydration)
• Phenoxyethanol 0.5% (Essential preservative)
• Water (Purified) up to 100%

Mixing Steps:

1. Measure the purified water.
2. Add and dissolve water-soluble ingredients: Allantoin, Panthenol, Hyaluronic Acid (Standard and Nano). Stir until fully dissolved.
3. Add Lactic Acid (90%) to the water phase and mix well.
4. Use a pH meter to measure the pH. It will be quite low.
5. Slowly add Sodium Lactate (60% liquid) while stirring and monitoring the pH. Add just enough to bring the pH into the target range of 3.5 to 4.0. Do not exceed pH 4.0 for optimal AHA effectiveness.
6. Add Phenoxyethanol and mix well.
7. Check the final pH again to ensure it is stable within the target range.

This revised formula removes incompatible ingredients (Urea, Bisabolol) and includes Panthenol for enhanced soothing, while maintaining the desired exfoliation from Lactic Acid at an appropriate pH. Always perform a patch test before using the finished product extensively. Remember to use sun protection daily when using this product.