Serum Formulation with Powders: Addressing Thickness and Dispersion Issues (Referencing SKII)

Here is the advice regarding your serum formulation:

1. Air bubbles in the Water phase from Gel Maker (Pro Polymer):

Small air bubbles often appear when gelling agents like Gel Maker (Pro Polymer) are mixed too quickly or vigorously, trapping air within the gel structure.

• Solution:
  • Reduce the mixing speed when adding the Gel Maker or as the mixture starts to thicken.
  • After mixing, let the gel mixture sit for a while (a few hours or overnight for larger batches) to allow the trapped air bubbles to rise and dissipate. You can gently stir with a spatula or tap the container lightly to help release the bubbles.

2. Undissolved Nylon-12 and Boron Nitride and excessive thickening:

The staff correctly advised that powders like Nylon-12 and Boron Nitride do not dissolve but need to be well-dispersed in the formula.

• Reason for excessive thickening with Tribehenin 5%: Tribehenin is a Soft Wax that adds viscosity and texture. Using 5% in a serum intended to be lightweight and fast-absorbing resulted in the observed thickness.
• Solution for good dispersion without excessive thickening: As the staff suggested, instead of using Tribehenin (a wax), use a dispersing agent that helps suspend powders well without adding significant thickness.
  • Recommended: Use LipidSoft™ Disperse or Triethylhexanoin in the Oil phase instead of Tribehenin. These are Emollient Esters that help disperse various powders effectively in oil or silicone phases and are compatible with other ingredients in your formula, without thickening as much as wax.
  • Suggested Amount: You can start with 5% as the staff suggested for LipidSoft™ Disperse, or consider the proportions of Triethylhexanoin and Caprylic/capric triglyceride in the SKII formula (which are relatively high, though exact percentages aren't listed) as they serve to disperse powders.
  • SKII Formula Analysis: The SKII Genoptics Aura Essence Serum formula contains sufficient amounts of oils/esters (Triethylhexanoin, Caprylic/capric triglyceride) and Glycols (Butylene Glycol, Pentylene Glycol). These ingredients help in the dispersion of powders (Nylon-12, Boron Nitride, Mica, Titanium Dioxide), allowing them to be evenly distributed while maintaining a lightweight serum texture. The formula also includes other ingredients for texture and emulsification to achieve the desired serum consistency.

Revised Manufacturing Steps (incorporating staff advice and using a Dispersing Ester):

1. Prepare Water phase (Heat-tolerant portion): Combine the remaining Water, Disodium EDTA, Niacinamide, Butylene Glycol, Glycerin, Polysorbate-20, and Gel Maker (Pro Polymer). Mix slowly until the Gel Maker is dispersed and a uniform gel is formed. Let it sit to release air bubbles (if any). Heat this portion to 60-70°C.
2. Prepare Oil phase (including powders): Combine Cyclomethicone (reduced to 15% or as needed), SiliSolve Plus 2%, Silicone Gel 4%, LipidSoft™ Disperse or Triethylhexanoin 5% (or adjusted amount), Nylon-12 2%, and Boron Nitride 2%. Stir well. Heat this portion to 70-80°C or until any solid components (like some dispersing esters if they are solid) are melted (powders will remain suspended, not dissolved).
3. Emulsify Water and Oil phases: While the Oil phase is still hot (around 70-80°C) and being mixed, slowly add the heated Water phase (60-70°C) into the Oil phase in small increments. Continue mixing at an appropriate speed to ensure the phases combine into a uniform emulsion.
4. Add Heat-sensitive Ingredients: Once the mixture is uniform, gradually add the heat-sensitive ingredients that were set aside: 1,2 Hexanediol, Double Hyaluron Liquid, MOIST72, and Phenoxyethanol. Mix until fully incorporated.
5. Cooling and De-aeration: Continue mixing until the formula cools down and is uniform. If air bubbles are still present, let the formula sit to allow them to rise and dissipate.

Switching from Tribehenin to a Dispersing Ester should help you achieve a lighter serum texture while ensuring the powders are well-dispersed. If the texture is still too thick, you might consider slightly reducing the amount of Gel Maker or the Dispersing Ester in future trials.