Formula Review and Recommendations

Thank you for providing your facial cleansing liquid formula and the staff's revised version. I have reviewed both formulas and the staff's feedback, considering your goal of a mild, effective cleanser with good foam and a slightly slippery feel.

The staff's revised formula simplifies the process significantly while aiming to maintain mildness and good cleansing properties.

Staff's Revised Formula Components:

• Glycerin (5%) and Propylene Glycol (5%): These are excellent humectants that help retain moisture and contribute to a smooth, slightly slippery feel on the skin, which aligns with your desired outcome.
• SugarThick™ (PEG-120 Methyl Glucose Dioleate) (1-5%): This is a suitable thickener for surfactant systems and can help achieve the desired viscosity.
• Sulfate Free Shampoo Base (20%): Replacing individual surfactants with a gentle, sulfate-free base simplifies the formulation process and is key to achieving mildness and good foam. This base is designed for cleansing products and is easy to thicken.
• Optiphen Plus (Phenoxyethanol SA) (1%): This is a broad-spectrum preservative essential for the stability and safety of the water-based formula. The usage rate of 1% is within the recommended range.
• Flora Foam™ (Dimethyl Lauramide/Myristamide) (5%): This ingredient acts as a foam stabilizer and can help boost foam volume and stability, which is one of your key requirements. It also assists with thickening in formulas containing amphoteric surfactants (likely present in the Sulfate Free Shampoo Base).
• Essential Oil (0.5%) and Color: These are for aesthetic and sensory purposes. Ensure the essential oil is suitable for facial use and used at a safe concentration.
• Water: The remaining percentage is water.

Staff's Reasoning for Changes:

The staff's decision to remove Lauryl Glucoside and Disodium Cocoyl Glutamate is valid from a simplification standpoint. These surfactants are alkaline and require pH adjustment with acid, adding a step to the process. Using a Sulfate Free Shampoo Base with a more neutral pH range (6.5-7.5) makes formulation easier.

The removal of Niacinamide and Zinc PCA is also reasonable for a wash-off product. While beneficial in leave-on treatments, their contact time in a cleanser is too short to provide significant active benefits like reducing oiliness or stimulating collagen.

Meeting Your Goals with the Revised Formula:

• Mildness: The Sulfate Free Shampoo Base is designed to be gentle and sulfate-free, contributing to mildness.
• Good Cleansing: The base should provide effective cleansing.
• Abundant Foam: The combination of the Sulfate Free Shampoo Base and Flora Foam™ should result in abundant and stable foam.
• Slightly Slippery Feel: Glycerin and Propylene Glycol will help provide this feel.

Suggested Adjustments:

The staff's revised formula is a solid foundation. To further optimize for mildness and skin compatibility, I recommend checking and potentially adjusting the final pH.

1. pH Adjustment: The Sulfate Free Shampoo Base has a pH of 6.5-7.5. While less alkaline than the original surfactants, a facial cleanser with a pH closer to the skin's natural pH (around 5.5) is generally preferred for optimal skin barrier health. After mixing all ingredients (except color and essential oil), measure the pH of the formula. If it is above 6.5, you can use a small amount of Lactic Acid (AHA) 88% (as included in your original formula) to carefully lower the pH to the range of 5.5-6.5. Add the Lactic Acid drop by drop, stirring well and checking the pH until the desired range is reached.
2. Disodium EDTA: Your original formula included Disodium EDTA. It is good practice to include a chelating agent like Disodium EDTA at 0.1-0.2% in the water phase, especially if you are not using distilled water. This helps chelate metal ions that can affect the stability and clarity of the formula. Add this to the water before adding other ingredients.

Revised Formulation Steps (incorporating suggestions):

1. In the water phase, add Disodium EDTA (0.1-0.2%) to the water (adjust water percentage accordingly). Stir to dissolve.
2. Add Glycerin (5%) and Propylene Glycol (5%) to the water phase. Stir to combine.
3. Add SugarThick™ (1-5%) to the water phase. You may need to warm it slightly (50-60°C) to help it dissolve and thicken the mixture. Stir gently until dissolved and the desired viscosity is achieved.
4. Add Sulfate Free Shampoo Base (20%) and Flora Foam™ (5%). Stir gently to avoid excessive foaming.
5. Add Optiphen Plus (1%). Stir gently.
6. Check the pH of the mixture. If it is above 6.5, add Lactic Acid (AHA) 88% drop by drop, stirring and checking the pH until it is in the range of 5.5-6.5.
7. Add Essential Oil (0.5%) and color if desired. Stir gently to combine.

This revised process, based on the staff's simplification but incorporating pH adjustment and optional EDTA for optimal skin compatibility and stability, should result in a mild, effective facial cleanser with good foam and a pleasant feel.