Cosmetic Formulation Guidance

Here is a breakdown of your formulation questions based on the ingredients and percentages provided for a 100% batch:

1. Mixing Order

For this type of serum or essence formulation, a suggested mixing order is as follows:

1. Combine the Propylene Glycol in a beaker.
2. Add the powdered ingredients: Alpha Arbutin, Vitamin B3 (Niacinamide), and Allantoin. Mix thoroughly until completely dissolved. Gentle warming may help dissolve Allantoin, but ensure the temperature is below 30°C before adding Alpha Arbutin and other heat-sensitive extracts.
3. Once the powders are dissolved and the mixture is cool (below 30°C), add the liquid extracts: Cucumber Extract, Aloe Vera Extract, Mulberry extract, and Wild Rose Extract. Mix well.
4. Check the pH of the final mixture. The optimal pH range for the actives and extracts in your formula is generally between 5.0 and 6.5. Adjust the pH if necessary.
5. Add a suitable broad-spectrum preservative system and mix until dispersed.

Ensure each ingredient is fully dispersed or dissolved before adding the next.

2. Amounts for a 100g Batch

Based on the percentages you provided, here are the exact amounts for a 100g batch:

• Propylene Glycol USP: 70.90 g
• Alpha Arbutin: 2.00 g
• Vitamin B3 (Niacinamide): 4.00 g
• Allantoin: 0.10 g
• Cucumber Extract: 5.00 g
• Aloe Vera Extract: 10.00 g
• Mulberry extract: 4.00 g
• Wild Rose Extract: 4.00 g

Total: 100.00 g

3. Need for Water and Preservatives

• Water: Your formula is primarily based on Propylene Glycol. While your list does not explicitly include added water, the extracts (Cucumber, Aloe Vera, Mulberry, Wild Rose) are typically supplied as aqueous or hydro-glycolic solutions, meaning they introduce water into the formula. A formula with 70.9% Propylene Glycol and these extracts can function as a serum or essence without adding extra water, depending on the desired viscosity and feel. If you prefer a less viscous product or if your extracts are in powder form, you would need to include water in the formulation, adjusting the Propylene Glycol percentage accordingly.
• Preservatives: Yes, a preservative system is essential for this formula. Even with a high percentage of Propylene Glycol, the presence of water introduced by the extracts makes the formula susceptible to microbial growth. While some extracts like Aloe Vera Extract may contain their own preservative (e.g., Phenoxyethanol), relying solely on this is often insufficient to protect the entire finished product from contamination over time. A broad-spectrum preservative system is necessary to ensure the safety and stability of your cosmetic product.