Question about EN product

Asked by: hahuuquy2002 On: April 09, 2026 Product Type: Cosmetics Answered

Question

Mình có công thức sữa rửa mặt
Aqua (p.s), Sodium Lauroyl Methylaminopropionate (7.0%), SCI (4.0%), DLS (4.0%), Lauryl Hydroxysultaine (4.0%), Coco-Glucoside (2.0%), Carbopol SF-1 (1.8%), Propylene Glycol (1.5%), Glycereth-26 (1.2%), Glycerin (1.0%), Betaine (1.0%), PEG-150 Distearate (1.0%), PEG-40 HCO (0.5%), Vitamin B5 (0.5%), Sodium Benzoate (0.5%), Chiết xuất vỏ cây liễu trắng (1%), PQ-39 (0.3%), Piroctone Olamine (0.2%), Chiết xuất lá trà xanh (0.3%), Chiết xuất ngải cứu (0.3%), Potassium Sorbate (0.2%), EDTA 2Na (0.1%), NaOH (p.s), Citric acid (p.s).
Nhưng sau khi thực nghiệm mẫu mình nhận lại không phải gel trong như mong muốn mà kết quả bị đục. Sử dụng hơi bị khô da
Nên tinh chỉnh và thực hiện quy tình khuấy như thế nào cho hợp lí
Mình đã dùng NaOH để đẩy pH lên 6.5 cho SF1 trương nở (Lúc này gel trong). Cuối quy trình mình có dùng Citric hạ pH về 5.4 nhưng bị đục.
Có phương án thay thế nào không?

Answer

The issues you are experiencing with cloudiness and skin dryness are common when formulating with certain surfactants and thickeners at specific pH levels.

1. Why the formula is cloudy

  • BabyFoam™ (Sodium Cocoyl Isethionate): This is the primary cause. While it is a very gentle surfactant, it is notoriously difficult to keep clear in liquid formulas, especially when the pH is lowered to 5.4. It tends to crystallize, leading to a cloudy or pearlescent appearance.
  • ThickClean™ (Acrylates Copolymer): This thickener requires a pH of 6.3–6.6 to achieve maximum clarity. When you use "Back-acid" to lower the pH to 5.4, the polymer chains can contract, which may reduce clarity if the surfactant system isn't robust enough to maintain the suspension.
  • Dandruff-Guard™ (Piroctone Olamine): If not fully solubilized within the surfactant system before thickening, it can also contribute to cloudiness.

2. Why it feels drying

  • High Surfactant Load: Your total active surfactant concentration is quite high (approx. 23-25%). Even with gentle surfactants, this concentration can strip the skin's natural oils.
  • Lack of Refatting Agents: The formula lacks water-soluble emollients that provide a smooth, non-stripping after-feel.

Recommended Adjustments

For Clarity and Mildness:

  1. Replace BabyFoam™: To achieve a crystal-clear gel at pH 5.4, replace it with IseFoam™ (Sodium Lauroyl Methyl Isethionate). It is a high-performance, water-soluble isethionate that remains clear even at lower pH levels.
  2. Alternative Thickener: If you find ThickClean™ too difficult to keep clear at pH 5.4, consider using SugarThick™ (PEG-120 Methyl Glucose Dioleate). It provides excellent thickening and clarity regardless of the pH.

For Better Skin Feel:

  • Reduce the total surfactant percentage slightly.
  • Increase Glycereth-26 or add a water-soluble emollient to reduce the "squeaky clean" feeling.

Optimized Mixing Procedure (using ThickClean™)

  1. Phase A: Mix Water, EDTA-2Na, and humectants (Glycerin, Propylene Glycol, Betaine).
  2. Phase B: Add ThickClean™ to the water phase and stir until dispersed.
  3. Phase C: Add surfactants in this order: AminoWash™, Sulfosuccinate L™, Flora-Sultaine™, and Coco-Glucoside. Stir gently to avoid excessive bubbles.
  4. Phase D: Add Ethoxylated Hydrogenated Castor Oil (pre-mixed with fragrance if any) and Polyquaternium-39.
  5. Phase E: Adjust pH to 6.3–6.6 using NaOH to fully neutralize and clear the ThickClean™ gel.
  6. Phase F: Add extracts, Dandruff-Guard™, and preservatives.
  7. Phase G (Back-acid): Slowly add a 10% Citric Acid solution while stirring to lower the pH to 5.4. If it turns cloudy here, it confirms the surfactant system (likely the original SCI) cannot support that pH in a clear state.

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