CAS Number:
9004-65-3
Chemical / IUPAC Name:
Cellulose, 2-hydroxypropyl methyl ether
INCI Name:
Hydroxypropyl Methylcellulose
EC Number:
618-389-6
Molecular Formula:
(C3H7O)n (simplified); polymeric structure with methoxy (-OCH?) and hydroxypropoxy (-OCH?CHOHCH?) groups attached to a cellulose backbone
Other Names:
HPMC, Hypromellose, Methyl Hydroxypropylcellulose, MHPC
Uses:
Hydroxypropyl Methylcellulose is a modified cellulose polymer that is water-soluble, odorless, and forms clear gels. It is widely used across industries for its thickening, stabilizing, and film-forming abilities .
· Cosmetics & Personal Care: Used in lotions, creams, shampoos, conditioners, styling gels, and facial masks as a thickener, emulsifier, and film-former. It improves texture, provides smooth application, and creates a protective barrier on skin/hair .
· Hair Care: Adds volume, controls frizz, and improves the texture of hair shafts in shampoos and styling products .
· Skin Care: Functions as a moisturizing agent, texture enhancer, and emulsion stabilizer. It helps maintain skin hydration by preventing moisture loss .
· Pharmaceuticals: Used in artificial tears (eye drops) for dry eye treatment, as a tablet binder, film coating agent, and matrix for extended-release formulations .
· Food Industry: Acts as a thickener, emulsifier, and stabilizer (food additive E464) in various products .
· Construction: Used as a cement additive to improve workability, water retention, and reduce cracking .
· Other Applications: Serves as a dispersing agent, suspending agent, and binder in industrial applications
Origin
Hydroxypropyl Methylcellulose is a semi-synthetic polymer derived from natural cellulose (typically from cotton linters or wood pulp). The production process involves:
· Treating cellulose with alkali (sodium hydroxide) to form alkali cellulose .
· Reacting with propylene oxide (to add hydroxypropyl groups) and methyl chloride (to add methoxy groups) .
· The resulting product is washed, purified, dried, and ground into a powder or granule form .
What does Hydroxypropyl Methylcellulose do in a formulation?
- Thickener / Viscosity Modifier: Increases the viscosity of aqueous systems, improving product consistency .
- Emulsifier / Emulsion Stabilizer: Helps stabilize oil-in-water emulsions, preventing separation .
- Film-Forming Agent: Creates a continuous, flexible film on skin, hair, or other surfaces, providing protective and moisturizing benefits .
- Binding Agent: Helps hold ingredients together in solid formulations like tablets and pressed powders .
- Suspending Agent: Keeps insoluble particles suspended in liquid formulations .
- Moisturizing Agent: Hydrophilic nature helps retain moisture and prevent dehydration .
- Texture Enhancer: Improves spreadability and provides a smooth, pleasant feel during application .
Safety Profile:
· General Hazard Classification: Considered safe for use in cosmetics and food. Classified as non-hazardous according to GHS regulations .
· Toxicity: Low acute toxicity. Oral LD50 (rat) > 5,000 mg/kg .
· Irritation & Sensitization: Generally regarded as non-irritating and non-sensitizing to skin. May cause mild eye irritation upon direct contact .
· Concentration Limits: Typically used at 0.2 – 2.0% in cosmetic formulations, with higher amounts (1-5%) used in gel formulations .
· Safety Assessments: The Cosmetic Ingredient Review (CIR) Expert Panel has determined it safe for use in cosmetics .
· Biodegradability: Readily biodegradable; no evidence of bioaccumulation .
· Regulatory Status: FDA approved for food use (21 CFR 172.874). EU registered as food additive E464. Approved for pharmaceutical and cosmetic use worldwide. Vegan and Halal compliant .
Technical profile:
| Property | Values |
| Appearance | White to off-white fibrous or granular powder |
| Odor | Odorless or slight characteristic odor |
| Methoxy Content | 19.0 – 30.0% |
| Hydroxypropoxy Content | 3.0 – 12.0% |
| pH (1% solution) | 4.0 – 8.0 |
| Loss on Drying | ≤ 5.0% |
| Residue on Ignition | ≤ 1.5% (varies by viscosity grade) |
| Heavy Metals (as Pb) | ≤ 20 ppm |
| Lead (Pb) | ≤ 3 mg/kg |
| Melting Point | 225 – 230°C (decomposes) |
| Density | 1.26 – 1.39 g/cm³ |
| Bulk Density | 0.25 – 0.70 g/cm³ |
| Viscosity Range | 5 – 200,000 mPa·s (2% solution, varies by grade) |
| Gelation Temperature | 50 – 90°C (varies by substitution type) |
| Solubility | Soluble in cold water, forming clear colloidal solutions; insoluble in hot water, ethanol, and ether |
| Stability | Stable at pH 3–11; thermally stable up to 200°C |
| Flash Point | 200°C |
| Recommended Use Level | 0.2 – 2.0% (cosmetics); up to 5% for gels |