Evaluation of Your Hair Removal Cream Formula

Your hair removal cream formula using Calcium Thioglycolate and Calcium Hydroxide is a standard approach for this type of product. The ratio of Calcium Thioglycolate to Calcium Hydroxide (9% to 1.8%) is correctly balanced at 5:1, which is important for the chemical reaction that removes hair.

Here are some points to consider and potential adjustments:

• Calcium Thioglycolate Concentration: While 9% Calcium Thioglycolate is within the FDA's allowed limit of 10%, the recommended usage rate is typically 5-7.5% to minimize the risk of skin irritation. You might consider reducing the concentration, especially if the product is intended for sensitive areas or users with sensitive skin.

• pH Level: It is crucial that the final formula has a high alkaline pH, specifically between 12 and 12.5, for Calcium Thioglycolate to be effective and safe. Your formula does not mention adjusting or measuring the pH. You will likely need to add a pH adjuster like Sodium Hydroxide or Potassium Hydroxide solution in the final phase to reach the required pH range. This is a critical step and should not be skipped. Always measure the pH of the final product and adjust as necessary.

• Ingredient Handling: The description for Calcium Thioglycolate suggests avoiding heat above 40°C (ideally 30°C) and recommends dispersing Calcium Thioglycolate and Calcium Hydroxide in a non-polar oil before mixing with the cream base. Your method of adding Phase C after cooling Phase A and B is good for temperature control. However, you might consider pre-dispersing the Calcium Thioglycolate and Calcium Hydroxide powder in a small amount of non-polar oil (if you are using any in your oil phase, though none is explicitly listed besides Dimethicone) before adding to the water phase of C, as per the ingredient's suggestion. Using high-purity water (like distilled water) for Phase C is also important to prevent discoloration caused by metal ions.

• Formula Stability (Discoloration): Calcium Thioglycolate can be prone to discoloration over time due to oxidation. The ingredient description recommends including ActiveProtec™ OX at 0.6% in the formula to help prevent this. Your current formula does not include this ingredient, which could affect the long-term stability and appearance of the cream.

• Packaging: To maintain the stability of the Calcium Thioglycolate, the finished product should be stored in packaging that minimizes contact with air, such as a vacuum tube.

• Emulsifier: You are using Emulium Delta. Ensure the concentration used is appropriate for the oil and water phases in your formula to create a stable emulsion.

Overall, your formula provides a good base, but incorporating pH adjustment, considering the Calcium Thioglycolate concentration based on target users/areas, ensuring high-purity water, and potentially adding a stabilizer like ActiveProtec™ OX will improve its efficacy, safety, and stability.

Remember to always perform a patch test before full application to check for skin sensitivity.