Product overview
Hydroxypropyl methyl cellulose phthalate (HPMCP) is an enteric coating polymer. It stays insoluble in stomach acid and dissolves at the higher pH of the small intestine, protecting acid-sensitive drugs and supplements.
Specification
| Property | Value |
|---|---|
| Appearance | White to off-white powder or granules |
| Methoxyl | 20.0–24.0% |
| Hydroxypropoxyl | 5.0–9.0% |
| Phthalyl | 27.0–35.0%, by grade |
| Moisture | ≤ 5.0% |
| Ash | ≤ 0.5% |
| Viscosity, 10% in acetone/ethanol | 40–60 or 136–204 mPa·s, by grade |
| Solubility | Insoluble in water below pH 5; soluble in acetone, ethanol and aqueous media above pH 5.5 |
Values are from our current product data. Confirm the exact grade and limits with the TDS and the COA of the lot you test.
Applications
- Pharmaceutical: enteric coating of tablets, pellets and granules
- Nutraceuticals: protective coating for acid-sensitive ingredients
Coating with HPMCP
HPMCP is applied from organic solvent mixtures such as acetone/ethanol, or from aqueous dispersions neutralised with ammonia. A plasticiser such as triethyl citrate or acetylated monoglyceride is usually added to give a flexible film. HPMCP films resist gastric fluid and dissolve quickly once the pH rises above the grade’s threshold.
| Grade type | Dissolves above | Typical use |
|---|---|---|
| Lower-phthalyl type | pH 5.0 | Release in the upper small intestine |
| Higher-phthalyl type | pH 5.5 | More acid resistance before release |
How to choose a grade
Choose the grade by the pH at which the coating must dissolve (about 5.0 or 5.5) and by the viscosity your coating process needs.
Packing and documents
25 kg multi-wall paper bags with an inner PE liner. Other packing is agreed per order. TDS, SDS and a representative COA are available for every grade, and each lot ships with its COA. Request documents or a sample.
Download (2026 revision): Technical data sheet (TDS, PDF) · Safety data sheet (SDS, PDF)
Related products
Related guides
FAQ
HPMCP or HPMCAS?
Both are enteric polymers. HPMCAS is also widely used for amorphous solid dispersions; HPMCP is a long-established enteric coating.
Can HPMCP be used for enteric capsules?
Yes. HPMCP is used to coat hard and soft capsules and to make enteric capsule shells, so the contents pass the stomach intact.
Is HPMCP soluble in water?
Not in acidic water. It dissolves in water only after neutralisation above about pH 5–5.5, and in solvents such as acetone and ethanol mixtures.