Hydroxyethyl Cellulose - HYE-C
INS No. 1525 CAS No. 9004-62-0

Hydroxyethyl cellulose, HYE-C, is used as thickener, suspending, dispersing, water retention & binding agent & protects various colloidal systems.

HYE-C or HEC is made by reaction polymerization of naturally obtained cellulose with sodium hydroxide & ethylene oxide. In the synthesis, the average number of moles of ethylene oxide that combines with each mole of cellulose & is controlled between 1.5 to 2.5. The number of hydroxy ethoxy groups are present typically in the range of 30 to 70%.

Hydroxyethyl cellulose, HYE-C, is a colorless to yellowish, free-flowing granular powder which dissolves easily into hot & cold-water giving shear thinning transparent solutions. The solutions have varying viscosities depending on type or MS of HEC, concentration & temperature. Molecular weight & degree of polymerization of HEC is directly proportional to viscosity.



Following types / grades of HEC can be distinguished
  • Low viscosity: 0.08 to 0.4 Pas at 5% w/w
  • Intermediate viscosity: 0.03 to 6.5 Pas at 2%w/w
  • High viscosity: 0.8 to 5Pas at 1%w/w


Pharmaceutical Syrup with HEC

Low & Intermediate viscosity grades of HEC are completely soluble in glycerol & good solubility in hydroalcoholic solutions that have 60% alcohol. HEC is insoluble in organic solvents. Non-ionic nature of HEC makes it less sensitive to pH changes.

Industrial applications of HEC are varied due to its water-binding, thickening abilities, & stability to wide range of pH due to its non-ionic nature. Thus, it is used in :

  • manufacture of pharmaceutical formulations,
  • building materials, (construction)
  • adhesives,
  • water-based paints & coatings – increases viscosity, improves flow & levelling.
  • making inks
  • stabilizer for liquid soaps, cleaning solutions & household products,
  • manufacturing ceramics,
  • emulsion polymerization etc.
  • oil & gas industry as drilling mud
  • welding rod making
  • joint filler formulation
  • water based personal lubricants.
  • strengthening of soap bubble & large bubble stabilization

Water based Paint with HEC


Toothpaste with HEC

Advantages of using HEC in making elegant pharmaceutical syrup formulas :
  • Improves appearance, viscosity & mouthfeel
  • Thickening & stabilization as it forms a gel-like network which prevents sedimentation, crystal formation & microbial degradation
  • Improves viscosity , mouthfeel, appearance
  • Enhanced bioavailability of even poorly soluble active ingredients, as it forms hydrophilic complexes
  • Safe, inert & well tolerated excipient

Water based inks, paints

In formulating oral care products, like toothpastes, mouthwashes, mouth moisturizers & mouth sprays & gels, HEC offers the following advantages :
  • Compatible with most active ingredients as it is non-ionic.
  • Excellent tolerance to mono-, di & tri- valent cationic co-ingredients
  • Provides rheology properties such as shear-thinning for ease of filling tubes during manufacture & dispensing onto a toothbrush.
  • Imparts glossy, smooth ribbon texture.
  • Inhibits syneresis of paste & gels due to its water binding capability.

Personal Lubricants with HEC

Salient properties of aqueous solutions of HEC
  • Viscosity increases with increase in concentration of HEC.
  • Viscosity of solution increases with decrease in shear rate & it decreases with increased shear rate, exhibiting thixotropy.
  • Viscosity is directly proportional to molecular weight of HEC.
  • Low viscosity systems show Newtonian fluid nature.

Large bubbles