Hydroxypropyl Methyl Cellulose Phthalate (HPMC-P)
(Hypromellose phthalate)
CAS:9050-31-1
Hydroxypropyl Methy Cellulose Phthalate (HPMC-P) is white or off-white granular solid which is tasteless and used as enteric sugar coating material with excellent gastric acid resistance, insoluble at pH PH=5.0-5.5. It’s mainly used in tablets, granules etc and also widely used in aquaculture, biotechnology and other industries.
Comply with USP 33
| ITEM | Specification | |
| HP55 | HP55S | |
| Methoxy (wt, %) | 18.0-22.0 | 18.0-22.0 |
| Phthaloyl group (wt, %) | 27.0-35.0 | 27.0-35.0 |
| Hydroxypropoxy (wt, %) | 5.0-9.0 | 5.0-9.0 |
| Viscosity (mPa.s) | 32-48 | 136-204 |
| Loss on drying (%) | ≤5.0 | ≤5.0 |
| Residue on ignition (%) | ≤0.20 | ≤0.20 |
| Chloride (%) | ≤0.07 | ≤0.07 |
| Heavy metals (ppm) | ≤10 | ≤10 |
– HPMC-P HP-55: initially soluble at pH = 5.5, viscosity 32~48 cst
– HPMC-P HP-55S: starts to dissolve at pH = 5.5, viscosity is 136~204 cst.
HP-55S has higher molecular weight than HP-55, so it has stronger mechanical strength (film-forming property) and stronger tolerance to gastric juice.
