Evaluation of Your Shampoo Formula

Your proposed shampoo formula appears generally usable based on the ingredients and percentages provided.

Here's a breakdown:

• Sulfate Free Shampoo Base: Used at 19%, which is within the acceptable range (5-40%) but on the lower side of the recommended range for adult formulas (25-35%). This might result in a less viscous or less foaming product than typical shampoos. You could consider increasing the percentage of the base or using a suitable thickener if you prefer a thicker consistency.
• Distilled Water: Appropriate as the main solvent.
• Calcium Pantothenate: Used at 2%, within the recommended range (0.1-3%).
• Hydrolyzed Rice Protein: Used at the recommended rate of 2% (range 1-4%). Note that this ingredient requires a preservative.
• Licochalcone A (from Licorice Extract): Used at 1%, within the recommended range (0.5-3%). This ingredient works best in a pH range of 3.5-6.5.
• Safe-B3 (Vitamin B3, Niacinamide): Used at 3%, within the recommended range (1-10%). The optimal pH range for this ingredient is 3-8 (best 4.0-7.0).
• Paeonia Preserve: Used at 2%. This ingredient can function as a single preservative at this concentration, which is important given the inclusion of Hydrolyzed Rice Protein. Ensure you follow the mixing instructions, avoiding heat above 60°C.
• Odor-Kill: Used at 1%, within the recommended range (0.3-3%). Be aware that Odor-Kill can absorb fragrances if you plan to add any to the formula. Follow the mixing instructions, avoiding heat above 50°C and adding in the final step.
• Citric Acid: Using Citric Acid to adjust the pH to 5.5 is appropriate. This target pH falls within the optimal ranges for Licochalcone A and Safe-B3 and is suitable for a shampoo formulation. Remember to add it gradually and measure the pH to reach your target.

Important Considerations:

• Always check the final pH of your formula after adding all ingredients and adjust with Citric Acid as needed to reach 5.5.
• While Paeonia Preserve is used at the recommended rate for a single preservative, it is highly recommended to perform a challenge test on your final formulation to ensure microbial stability and safety, especially since Hydrolyzed Rice Protein can support microbial growth.
• Consider the desired viscosity and foaming properties. If the current formula is too thin, increasing the Sulfate Free Shampoo Base or adding a compatible thickener might be necessary.

Overall, the formula is a good starting point, and with careful pH adjustment and consideration of stability, it should be usable.