Cosmetic Formulation Advice

Here is the information regarding your cosmetic formulation questions:

Regarding your first question about adding Salicylic Acid EZ™ and Encapsulated Salicylic Acid to glycerin bar soap, it is generally not recommended. Glycerin bar soap requires a high alkaline pH to maintain its solid form. Adding acidic ingredients like Salicylic Acid will lower the pH, which can cause the soap to become soft or not solidify properly.

For the acne treatment formula provided in the thread, you can generally mix it with other ingredients beyond those listed as incompatible, as long as the added ingredients are compatible with the existing components and do not negatively affect the stability, efficacy, or safety of the formula.

Since adding Salicylic Acid to bar soap is problematic, here is a recommended formula for an acne gel cleanser:

Acne Gel Cleanser Formula

• Renewing SA Cleanser (Compare to Cerave, 2.0% Salicylic Acid): 90%
• Zinc PCA: 1%
• Allantoin: 0.2%
• Panthenol (Vitamin B5): 1%
• Phenoxyethanol SA: 1%
• Purified Water: up to 100%

Mixing Steps:

1. In a container, combine Purified Water, Allantoin, Panthenol, and Zinc PCA. Stir until all powders are fully dissolved.
2. Gently add the Renewing SA Cleanser base to the mixture. Stir slowly to combine the ingredients without creating excessive foam.
3. Add Phenoxyethanol SA and stir gently until evenly distributed.
4. Check the pH of the final product to ensure it is within a suitable range for Salicylic Acid (typically pH 4-6).

Regarding the issues you experienced with the provided acne treatment formula (warm sensation, stickiness, film, pilling, and liquid texture):

• The warm sensation can be caused by the high concentration of Salicylic Acid EZ™ or the penetration enhancer PE-1 Aqua. If there is no irritation or rash, this sensation might be acceptable.
• The stickiness, film-forming, and pilling issues are likely due to the high concentration of Salicylic Acid EZ™ and potentially the interaction with the gelling agent or emulsifier used, especially if not fully mixed. As suggested in the forum, adding a small amount of Ethyl Alcohol (starting at 5%) can help reduce stickiness and improve the drying time, which might lessen pilling.
• The formula being liquid instead of a cream, even with 1.5% Light Cream Maker™, suggests that the amount of emulsifier/thickener might not be sufficient for the overall composition, or there might be compatibility issues causing it to not thicken properly. Light Cream Maker™ can be sensitive to electrolytes (ingredients with Sodium, Magnesium, Calcium, Potassium, like Zinc PCA in this formula). While Light Cream Maker™ has some electrolyte tolerance, a high concentration of electrolytes might reduce its thickening power. Also, insufficient mixing speed or time can prevent proper emulsification and thickening, leading to a liquid texture and pilling. Trying a different cream maker like Satin Cream Maker™, which is noted to have higher electrolyte resistance and oil binding capacity, could help achieve a better texture and reduce pilling. Ensure thorough mixing, potentially using a higher speed mixer if available and appropriate for the ingredients.

For the whitening formula being slightly sticky and slow to absorb:

• The main contributor to the slow absorption and slight stickiness is likely the Mineral Oil. Mineral Oil is an occlusive ingredient that forms a barrier on the skin, which can feel heavy and take time to absorb. As suggested, removing the Mineral Oil is the best way to improve absorption speed and reduce stickiness.
• Replacing Mineral Oil with lighter emollients or silicones (like Cyclomethicone, PowderCream, SiliSilk, or MatteSilica) would result in a much lighter feel and faster absorption. While Rose Hip Oil can be used as an alternative oil, it is still an oil and may not provide the same level of lightness and fast absorption as silicones or lighter synthetic emollients.

Finally, regarding adding Goat Milk Powder to the Triple Whitening Cream formula, yes, you can add Goat Milk Powder by mixing it into the water phase of the formula. Remember that Goat Milk Powder does not contain preservatives, so ensure your formula has an effective preservative system like Phenoxyethanol SA to maintain stability and prevent microbial growth.