WS SA50™ Water Soluble Salicylic Acid: At Last, an Easy Way to Design Unique Salicylic Acid Formulations

Salicylic Acid and Its Formulation Challenges

Salicylic acid (SA) is a commonly used active in many skincare and OTC products. As a keratolytic active exhibiting also anti-inflammatory and exfoliating properties, SA can soothe sensitive skin, reduce redness, and work as an anti-inflammatory agent to treat acne and other breakouts. However, SA is a crystalline powder, which has poor water solubility (0.2g/100ml at 20°C), making it difficult to prepare water-based SA formulations.

While topical SA is widely found in creams, lotions, liquids, gels, ointments, shampoos, wipes, pads, and patches, cosmetic formulators often combine it with other active agents for the SA formulation to be more effective. Yet these additions can sometimes have adverse effects for users. For example, they can unintentionally harm users' skin or create visually noticeable problems in the formula, such as crystallization, that detract from the product's consumer appeal.

Notably, a preferred additive of cosmetic formulators to solubilize SA is alcohol. Alcohol has always remained a good sanitizer, but when used in the context of SA-based cosmetic formulations, it can have big drawbacks such as dry skin, irritation, and an overall negative impact on the formula's desired results and aesthetic.

Tagra's Solution

To improve salicylic acid's effectiveness in cosmetic formulations, Tagra has developed a unique, innovative solution: WS SA50™. WS SA50™ is a water soluble, dry powder form of SA (50% w/w), offering a higher solubility level of 5g/100ml compared to 0.2g/100ml for free SA. Tagra's unique technology leads to a significant increase in aqueous solubility without high-energy investment, showing WS SA50™ to be highly efficient.

How Do We Know It Works?

In measuring WS SA50™'s efficacy in a disk diffusion assay, the results show that a 4% WS SA50™ water solution is more efficient than a traditional hydroalcoholic formula of 2% free SA and an Ampicillin 4µg/ml solution for inhibiting P. acnes growth.

Figure 1: Demonstration of antibacterial properties of WS SA50™ against P. acnes tested in-vitro by Disc Diffusion Assay.

Similarly, when conducting the Minimum Inhibitory Concentration (MIC) test for both the 4% WS SA50™ and 2% free SA, the 4% WS SA50™ water solution had nearly double the efficacy of the same amount of 2% free SA. At these levels, WS SA50™ inhibited P. acnes growth far better than the solution with 2% free SA.

Figure 2: Inhibition of P. acnes growth by MIC. The Minimum Inhibitory Concentration of 4% WS SA50™ in DW or 2% free SA in hydroethanolic solution was examined at 0.0%, 3.1%, 6.3%, 12.5%, 25.0% and 50.0% tested sample in growth medium.

How to Formulate with It?

WS SA50™ is a pertinent solution for many industries, including skincare, sun care, haircare (shampoos, conditioners), aerosol products (sun spray, deodorants etc.), cleansers, and more. Formulating with WS SA50™ results in a pH of 3-5 and does not require using any organic solvents for solubilizing SA. It prevents any risk of crystallization in the formula, and it is added to the formulation at room temperature using a simple paddle mixer or homogenizer, as needed.

Request a sample of the Tagra ingredients in this formula at tagra.com/engine.