Polyhydroxystearic Acid Low Viscosity (INCI: Polyhydroxystearic acid)

Polyhydroxystearic Acid (Low Viscosity) is a biodegradable, plant‑derived polymer from castor oil. It is widely used in cosmetic and personal‑care formulations as a pigment dispersant, emulsion stabilizer, and sensory enhancer. Its ability to evenly distribute mineral UV filters (like Zinc Oxide and Titanium Dioxide) makes it a key ingredient in sunscreens, BB creams, and color cosmetics, reducing white cast and improving texture.

Technical Information

• INCI Name: Polyhydroxystearic Acid
• CAS Numbers: 27924‑99‑8 / 58128‑22‑6
• Appearance: Soft waxy liquid, low viscosity
• Origin: Derived from 12‑hydroxystearic acid (castor oil)
• Functions:
  • Pigment dispersant for UV filters & colorants
  • Water‑in‑oil emulsion stabilizer
  • Texture enhancer & emollient
  • Film former & gloss improver
• Safety: Reviewed by CIR (Cosmetic Ingredient Review) panel, considered safe and chemically inert for skincare applications

Usage Information

• Sunscreens: Boosts SPF efficacy by ensuring uniform dispersion of Zinc Oxide/Titanium Dioxide.
• Skincare: Improves spreadability, reduces greasiness, and enhances skin feel.
• Color Cosmetics: Provides gloss, smoothness, and even pigment distribution in lipsticks, foundations, and BB creams.
• Formulation Notes:
  • Effective in oil‑based and water‑in‑oil emulsions.
  • Reduces viscosity for sprayable or lightweight textures.
  • Helps eliminate chalky white residue in mineral sunscreens.