HPMC is a variety of natural plant cellulose, and it is also an excellent pharmaceutical excipient, which has a wide range of sources. At present, it is widely used at home and abroad, and it is one of the pharmaceutical excipients with the highest utilization rate in oral drugs. HPMC plays a vital role in pharmaceuticals and can be used as suspending agent, adhesive, disintegrant, thickener, film coating material, capsule material, etc.
The chemical formula of HPMC is 86,000, and it is formed by the combined etherification of methyl oxirane, chlorinated alkanes, and sodium cellulose. The appearance of HPMC is white or yellowish granules, non-toxic and tasteless, relatively stable under light and humidity. It swells in cold water to form a milky white colloidal solution with a certain degree of viscosity. It is very soluble in 70% alcohol or dimethyl ketone, and will not dissolve in absolute alcohol, chloroform or ethoxyethane;
When the pH of hydroxypropyl methylcellulose is between 4.0 and 8.0, it has good stability, and it can exist stably when the pH is between 3.0 and 11.0. When the temperature is 20°C and the relative humidity is 80%, it can be stored for 10 Days later, the moisture absorption coefficient of HPMC was 6.2%.
2.1 Used as binder and disintegrant
Binders and disintegrants play a vital role in pharmaceuticals. Hydroxypropyl methylcellulose can be used as a binder and a disintegrator to rapidly dissolve and release drugs.
Hydroxypropyl methylcellulose with low viscosity dissolves in water to form a clear to milky white colloidal solution with a certain viscosity, and can be used as a binder and disintegrating agent for granules, tablets and pills in oral medicine. However, its high viscosity can only be used as a binder, and the usual amount is 2%-5%.
In addition, HPMC liquid solution has a certain viscosity, which can be used as a binder and can be wrapped on oral drug particles, which can help the group maintain the stability of the drug, and the binder is especially suitable for unstable drugs.
2.2 Used as a film coating material
HPMC is a coating material among water-soluble substances, and its film-forming property is very high. The coating film formed by hydroxypropyl methylcellulose has the advantages of being strong, transparent, and not easy to stick. The role of isolation can significantly improve the stability of the drug, and can avoid discoloration of the tablet drug.