HPMC (Hydroxypropyl Methyl Cellulose) and HPC (Hydroxypropyl Cellulose) are both cellulose derivatives, widely used in the pharmaceutical, food, construction and cosmetic industries. Although the two are similar in some aspects, they are obviously different in chemical structure, physical and chemical properties, solubility and application areas.
1. Chemical structure and properties
HPMC is made by methylation and hydroxypropylation of natural cellulose, and contains methoxy (–OCH₃) and hydroxypropoxy (–OCH₂CHOHCH₃) groups in the molecule.
HPC is obtained by hydroxypropylation of cellulose, and its main functional group is hydroxypropoxy (–OCH₂CHOHCH₃), without methoxy.
Because HPMC contains an additional methoxy group than HPC, HPMC is slightly more hydrophobic, while HPC is more hydrophilic. In addition, the molecular weight of HPMC is usually higher, while the molecular weight of HPC can be more flexibly controlled, which affects the solubility and viscosity characteristics of the two.
2. Water solubility and solubility characteristics
HPMC dissolves in cold water to form a transparent or translucent colloidal solution, but is insoluble in hot water. Therefore, HPMC needs to be pre-dissolved or dispersed using special methods in some applications.
HPC has good water solubility and can be dissolved in cold water and some organic solvents, such as ethanol, methanol, etc., and has good thickening and film-forming properties.
HPMC has a thermogel property. When the temperature rises, the solution may phase separate, while HPC usually does not form a thermogel, so HPC has better stability in high temperature environments.
3. Viscosity and rheological properties
HPMC has a higher viscosity and is usually used as a thickener, stabilizer and film-forming agent. Its rheological properties in aqueous solution are closer to pseudoplastic fluids.
HPC has a lower viscosity and is more suitable for formulations that require better fluidity, such as oral drugs and coating materials.
4. Application fields
Due to the differences in physical and chemical properties between HPMC and HPC, they play different roles in different industries and products:
Pharmaceutical industry
HPMC is mainly used as a binder, sustained-release material, film coating material for pharmaceutical tablets, and as a shell component for hollow capsules. Its good film-forming property and water solubility make it a preferred excipient for sustained-release preparations.
HPC is mainly used as a disintegrant, binder, solubilizer, and bioadhesive material for tablets, and is suitable for improving the solubility and bioavailability of drugs. In addition, HPC is more widely used in hot melt extrusion technology than HPMC.
Food industry
HPMC can be used as a food thickener, emulsifier, stabilizer, and emulsifier stabilizer for non-dairy cream.
HPC is mainly used as a food thickener, emulsifier, and improver, and is suitable for sugar-free and low-calorie foods.
Cosmetics and personal care
HPMC can be used in skin care products and detergents as an emulsifier stabilizer.
HPC is more suitable for hair care products, moisturizers and eye care products due to its good water solubility and lubricity.
Building materials
HPMC is an important component of architectural coatings, mortars, and putty powders, which plays a role in thickening, water retention and enhancing adhesion.
HPC is less used in the construction industry, but can be used in specific water-soluble coatings and adhesives.
5. Environmental protection and safety
Both HPMC and HPC are derived from natural cellulose and have good biodegradability and safety. HPMC is generally considered to be non-toxic and non-irritating, while HPC is also widely used in food and medicine, meeting the safety requirements of the FDA (U.S. Food and Drug Administration) and other international standards.
6. Selection suggestions
If higher viscosity and film-forming properties are required, HPMC is suitable, such as tablet coating, architectural coatings and other applications.
If better solubility and biocompatibility are required, HPC is suitable, such as oral drugs, hot melt extrusion components, etc.
HPMC and HPC are both important cellulose derivatives, which differ in chemical structure, solubility, and application areas. HPMC is more suitable for high viscosity, hot gel-forming applications such as tablet coating and building materials, while HPC is more suitable for oral preparations, cosmetics and food improvers due to its good water solubility and low viscosity. According to specific needs, choosing the right material can improve the performance and stability of the product.
Post time: Mar-28-2025