Introduction
HPMC is white powder, tasteless, odorless, non-toxic, completely unchanged in the human body and excreted. The product is soluble in water, and the aqueous solution is a colorless, transparent, viscous substance. HPMC has excellent thickening, emulsifying, film-forming, dispersion, protective colloids, adhesion, acid and alkali resistance, anti-enzyme and other properties, and is widely used in construction, coatings, pharmaceuticals, food, textile, oilfields, cosmetics, detergents, ceramics, inks and chemical polymerization process. As the renewable awareness of energy and pollution problems of the environment have got widespread concern and attention, the applications of natural cellulose and its derivatives have been developed.
HPMC can be used as one of the pharmaceutical excipients with the largest amount at home and abroad currently, for it has many characteristics other excipients do not have.
As a pharmaceutical excipient, HPMC has great application value, and it has the advantages that other excipients do not have, so has been widely used in recent years, especially in the pharmaceutical industry. It has great superiority as an excipient. Research and development of it is of great significance to make it applied in wider industries.
Advantage of HPMC in medicine
In medicine, Hydroxy Propyl Methyl Cellulose can be used in various dosage forms. In tablets, pills, powders, liquid, emulsions, suspensions, and paste, it can be used as binding, thickening, separating, releasing, stabilizing and emulsifying agents.
1. Hydroxy Propyl Methyl Cellulose has bonding and film-forming properties as well as thickening and dispersion effects in the liquids. Furthermore, it is of no nutritional value, so won’t make metabolic changes. It is also activated in fat. Consequently, it is widely used in medicine.
2. Hydroxy Propyl Methyl Cellulose has dump-proof as well as mildew-proof functions, and can improve the hardness, strength and elasticity of tablets. In food, it can be applied to sweets and cakes, and it can prevent grease penetrating and retain moisture, in addition to dump-proof as well as mildew-proof functions.
3. Hydroxy Propyl Methyl Cellulose is a non-ionic mixed cellulose ether, so its solution has no ionic charge, and does not react with metal salts or ionic compounds. It will not affect the efficacy.
4. Hydroxy Propyl Methyl Cellulose has strong enzyme resistance, which will be enhanced with the increase of degree of substitution. So it has great advantages for storage of made drugs over other sugar and starch products, and can also reduce the possibility of going moldy.
5. Hydroxy Propyl Methyl Cellulose is metabolically inert, so as pharmaceutical excipients, it won’t be metabolized or absorbed. In food, it does not provide heat, so it has peculiar usability on the food of low calorific value, no salt, no change in immunogenicity suitable for people with diabetes.
6. Hydroxy Propyl Methyl Cellulose has stability to acids and bases. However, if the pH value is beyond the range of 2-11, its viscosity will be reduced at high temperatures or stored for a long time.
7. Hydroxy Propyl Methyl Cellulose aqueous solution has surface activity, belongs to non-ionic surface-active agents, and can exhibit moderate surface tension and interfacial tension values. In the two-phase system, it has an effective emulsification effect , so can be used as an effective stabilizer and protective colloid agent.
8. Hydroxy Propyl Methyl Cellulose solution has excellent film-forming performance and can provide good conditions for tablets, pills and coating. The mold formed has such characteristics as being colorless, transparent and tough. If added with glycerin, its flexibility can be increased. When it is used as film coating materials, depending on the viscosity grade type, the content range is 2% to 10%, low viscosity, high concentration of the coating solution film products that do washed, high viscosity products can be dubbed an organic solvent solution.
