Adjusting the pH of Cream

If your cream has a pH value below 3 (too acidic) or above 8 (too alkaline) and you wish to adjust it to a neutral pH of around 7, you can do so by using appropriate pH adjusters.

Principle:

• If the cream is too acidic (pH below 3): Use a basic substance to increase the pH.
• If the cream is too alkaline (pH above 8): Use an acidic substance to decrease the pH.

Common Ingredients Used as pH Adjusters in Cosmetics:

• For increasing pH (adjusting from acidic to alkaline):

  • Sodium Hydroxide: A highly alkaline substance, often used in dilute solutions for gradual pH adjustment.
  • Triethanolamine 99%: A pH adjuster used to increase alkalinity in cosmetic formulas. Should be used according to recommended rates.

• For decreasing pH (adjusting from alkaline to acidic):

  • Citric Acid (Anhydrous, Natural): A natural acid commonly used to lower pH. It dissolves easily in water.
  • Lactic Acid (AHA) 90% (ordinary grade - smells) / Lactic Acid (AHA) 90% Deodorized (odorless): An AHA acid that can also be used to lower pH. Available in both ordinary and low-odor grades.

Method for Adjusting pH:

1. Prepare Solution: Prepare the desired pH adjuster in a dilute solution first (e.g., 10% or less) to make it easier to control the pH change.
2. Add Gradually: Slowly add the prepared pH adjuster solution to the cream, a very small amount at a time.
3. Mix: Stir or mix the cream thoroughly after each addition.
4. Measure pH: Use a pH meter or pH strips to measure the pH of the cream after adding and mixing.
5. Repeat: Repeat steps 2-4 until the desired pH (around 7) is achieved.

Precautions:

• Adjusting pH should be done slowly and patiently, as adding too much pH adjuster at once can cause the pH to change rapidly and be difficult to correct.
• Wear necessary gloves and protective equipment for safety when working with chemicals.
• The amount needed will vary depending on the specific formula and quantity of your cream.