Formulation Stability and Preservation

Regarding your formula of 3% Horse Placenta Extract and 97% Aloe Vera Gel:

Based on the product information, the Aloe Vera Gel bases (such as Aloe Vera Gel (Lite) and Aloe Vera Gel (Heavy)) already contain Phenoxyethanol at 0.40% as a preservative.

This means your proposed formula already includes a preservative system from the Aloe Vera Gel component. The concentration of Horse Placenta Extract at 3% is within the recommended usage range (0.1-5%, ideally 1-3%).

While the base contains a preservative, adding other ingredients can sometimes affect the overall stability and microbial resistance of the final product. Therefore, although your formula contains a preservative from the base, it is highly recommended to perform stability testing and microbial challenge testing on your final product to ensure its safety and shelf life, especially if you intend to store it long-term or for commercial purposes.