Lactic Acid Lotion Formulation Guide

This guide outlines the general process for creating a basic lotion with Lactic Acid for keratosis pilaris. Making a lotion involves combining oil and water phases with an emulsifier. It's a bit more complex than making a gel, but definitely achievable with the right steps and ingredients.

Ingredients Needed (Example)

• Water Phase:
  • Purified Water (or Distilled Water) - This forms the bulk of your lotion.
  • Lactic Acid (AHA) 88% - The active ingredient for exfoliation.
• Oil Phase:
  • Carrier Oil (e.g., Sweet Almond Oil, Grapeseed Oil, Jojoba Oil) - Provides emolliency and skin conditioning.
  • Emulsifying Wax 1000 - To bind the oil and water phases together.
• Cool Down Phase:
  • Mild Preserved™ COS - A broad-spectrum preservative to prevent microbial growth.
  • pH Adjuster (e.g., Triethanolamine or Sodium Hydroxide solution) - To adjust the final pH.

Equipment Needed

• Accurate Digital Scale (capable of measuring to 0.1g or 0.01g)
• Heat-resistant Beakers or Containers (at least two, one for water phase, one for oil phase)
• Heating Device (like a hot plate or double boiler)
• Stirring Device (glass stirring rod, mini-mixer, or stick blender for better emulsion)
• Thermometer (to monitor temperature)
• pH Meter or pH Strips (essential for checking and adjusting pH)
• Gloves and Eye Protection (for safety)
• Containers for the finished product

Step-by-Step Mixing Instructions

1. Prepare Phases:

   • Weigh all ingredients for the Water Phase into one beaker.
   • Weigh all ingredients for the Oil Phase into a separate beaker.

2. Heat Phases:

   • Gently heat both the Water Phase and the Oil Phase simultaneously using a hot plate or double boiler.
   • Heat until the Emulsifying Wax in the Oil Phase is completely melted and both phases reach approximately 70-75°C. This ensures proper emulsification.

3. Combine Phases:

   • Slowly pour the heated Water Phase into the heated Oil Phase while continuously stirring.
   • Continue stirring vigorously for several minutes (using a stick blender for 1-2 minutes is highly recommended) to create a stable emulsion.

4. Cool Down:

   • Remove the beaker from the heat.
   • Continue stirring occasionally as the lotion cools. As it cools, it will start to thicken.

5. Add Cool Down Ingredients:

   • Once the lotion has cooled to below 45°C, add the Lactic Acid (AHA) 88% and Mild Preserved™ COS.
   • Mix thoroughly until all ingredients are evenly dispersed.

6. Check and Adjust pH:

   • This is a critical step when using AHA. Use your pH meter or pH strips to measure the pH of the finished lotion.
   • For consumer use, the pH of a product containing AHA should be no lower than 3.5.
   • If the pH is too low, add a small amount of your pH adjuster (like a dilute solution of Triethanolamine or Sodium Hydroxide), mix well, and re-measure the pH. Repeat until the pH is within the safe and effective range (ideally between 3.5 and 4.0 for optimal AHA activity and safety).

7. Final Mix and Packaging:

   • Give the lotion a final thorough mix.
   • Carefully pour the finished lotion into your clean, sanitized containers.

Important Considerations

• Usage Rate: For consumer products, the concentration of Lactic Acid should not exceed 10%.
• pH Level: Maintaining the correct pH (above 3.5 for consumers) is crucial for both the efficacy and safety of the Lactic Acid. A pH that is too low can cause irritation.
• Sun Sensitivity: Products containing AHA can increase your skin's sensitivity to the sun. Always use sun protection on areas where you apply the lotion.
• Patch Testing: Before applying the lotion to large areas, perform a patch test on a small area of skin to check for any adverse reactions.
• Alternative AHA: As mentioned in the staff reply you received, Glycolic Acid is another effective AHA for exfoliation and may have less odor than Lactic Acid.

This process provides a basic lotion. You can customize it further by adding other beneficial ingredients like humectants (e.g., Glycerin), emollients (other oils or butters), or other active ingredients, keeping in mind their compatibility and recommended usage rates.

I hope this detailed guide helps you in making your Lactic Acid lotion!