How to Make 20% Urea Cream (for 100g)

A 20% concentration of Urea cream has both exfoliating (keratolytic) and high moisturizing properties, making it suitable for very dry skin and Keratosis pilaris.

Ingredients:

• Urea (High Purity, Cosmetics, Powder): 20 grams
• Purified Water: 10-15 grams (Use just enough to fully dissolve the Urea)
• Pre-made Cream or Lotion Base: 65-70 grams (Adjust based on the amount of water used to dissolve Urea, ensuring the total of dissolved Urea solution and base is 80g)

Preparation Steps:

1. Dissolve the Urea: Weigh out 20 grams of Urea and the required amount of purified water. Gradually add the Urea to the water, stirring or mixing until the Urea is completely dissolved. You can gently warm the water (not exceeding 60°C) to help it dissolve faster. Let the solution cool down once dissolved.
2. Combine with Base: Weigh out the calculated amount of your pre-made cream or lotion base. Slowly pour the prepared Urea solution into the base while stirring or mixing continuously.
3. Mix Thoroughly: Mix all ingredients thoroughly until the cream is smooth and homogeneous. Ensure no Urea crystals remain.
4. Packaging: Transfer the finished cream into a clean and suitable container.

Additional Considerations:

Urea Stability

Urea can decompose over time, especially at temperatures above 35°C and when the pH increases. This decomposition can lead to an ammonia smell. To enhance stability and extend the shelf life of your Urea cream, you can use Gluconolactone (such as Natural PHA (Gluconolactone)) at approximately 15% of the Urea amount (e.g., if using 20% Urea, use about 3% Gluconolactone) to help control the pH within the optimal range (4-5.5), which improves Urea stability.

Enhanced Moisturizing Efficacy

According to the product information for Urea (High Purity, Cosmetics, Powder), using Urea in combination with Sodium PCA (such as Sodium PCA 50%) and Sodium Lactate (such as Sodium Lactate (60% Liquid, Natural)) will maximize moisturizing efficiency. These three substances are key components of the skin's natural Natural Moisturizing Factor (NMF). You can consider adding these ingredients to your formula based on their recommended usage rates in skincare products.

Preservation

If your cream or lotion base does not contain a preservative, or if adding the Urea solution dilutes the existing preservative concentration, you should add a suitable preservative to your formula to prevent microbial growth, as the cream contains water.

Hygiene

Maintain cleanliness of all equipment and containers used during preparation to prevent contamination.

Experimentation

It is recommended to start by making a small batch first to test the process, texture, and stability of the resulting cream before deciding to make larger quantities.