Comparison
HPMC vs PVA based tablet coating
The two immediate release film formers. One is the default, the other is the moisture barrier.
Written by Rglax Pharma, who manufacture coating material · Reviewed 25 August 2026
Almost every immediate release film on the market is built on one of these two. They are not interchangeable. HPMC is the long standing default and the cheaper route; PVA exists because HPMC does not hold moisture out well enough for a hygroscopic active. Picking on price alone is how a stability failure arrives eighteen months later.
| Criterion | HPMC (hypromellose) | PVA (polyvinyl alcohol) |
|---|---|---|
| Role | General purpose immediate release film | Moisture barrier and immediate release |
| Moisture protection | Modest | Substantially betteredge |
| Oxygen barrier | Limited | Betteredge |
| Film strength | Adequate, more brittle | More flexible, better on friable coresedge |
| Logo definition | Good | Good, less bridging at equal build-upedge |
| Cost per kg | Loweredge | Higher |
| Build-up needed for cover | Higher | Loweredge |
| Aqueous processing | Standard | Standard |
| Also used for | Seal coat, sugar film, sub-coat | Barrier layers under sensitive actives |
| Regulatory familiarity | Very widely filededge | Widely filed |
| Zone IVb stability | Often the weak point | The reason to switchedge |
Our verdict
Use HPMC unless the active or the market gives you a reason not to. Move to PVA when the product is hygroscopic, when you are exporting into a hot and humid stability zone, or when an HPMC film has already failed a stability pull.
Choose HPMC (hypromellose) when
A stable active, a temperate market, cost sensitivity, or a filing that already names hypromellose.
Choose PVA (polyvinyl alcohol) when
A hygroscopic or moisture labile active, export into ICH Zone IVb, a friable core that chips under an HPMC film, or a stability failure you are trying to design out.
How to decide
Work it out from your own product.
The question is not which polymer is better, it is whether your product needs a moisture barrier. Look at three things: whether the active is hygroscopic or hydrolyses, which ICH stability zone your market sits in, and whether an existing film has ever failed a stability pull. If all three come back clean, HPMC is the cheaper and more widely filed choice and there is no reason to move. If any one of them raises a flag, the cost difference between the two polymers is trivial against the cost of a stability failure discovered late.
Where this goes wrong
- 01Specifying on cost per kilogramPVA costs more per kilogram and reaches cover at a lower build-up, so the cost per tablet gap is much smaller than the cost per kilogram gap suggests. Compare per tablet.
- 02Treating PVA as a substitute for a desiccant or a better packA moisture barrier film slows ingress, it does not stop it. A product that needs alu-alu still needs alu-alu.
- 03Switching polymer without re-running the processPVA and HPMC do not behave the same at the same spray rate and bed temperature. A straight swap at the old parameters usually shows up as roughness or tackiness.
- 04Ignoring the export market when specifyingA film that holds in a temperate warehouse can fail a Zone IVb pull. Decide against the hardest market the product will reach, not the nearest one.
Questions about HPMC (hypromellose) and PVA (polyvinyl alcohol)
Grades either way
- AQ-ZWt10Aqueous film coat, extra whiteWater base extra white film coat for cores that show through a standard white.Film coating
- MB 31RPMoisture barrier for multivitamin and ferrous tabletsSolvent base barrier film for hygroscopic multivitamin and iron formulations.Moisture barrier
- SC-401Transparent seal coat and pre-coatClear sub-coat laid down before an enteric layer on acid labile cores.Seal and pre-coat