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HP (HPMC-P) - Hypromellose Phtalate - polymere gastro-resistant


Hypromellose Phtalate - polymer for gastro-resistant coating

HPMC-P (Hypromellose Phtalate) has been used since the 1970s as a polymer for gastro-resistant coating.

The HP range from SHIN ETSU is compliant with Ph.Eur, JP and USP.

Gastro-resistant polymer

The principle of a gastro-resistant polymer is its capacity to be insoluble at acid pH (<5) and to become soluble as the pH increases.

It can therefore be used to maintain the integrity of the active ingredient in the stomach and then release it in the intestine. The gastro-resistant polymer can also protect gastric mucosa from irritating active ingredients.

Using film-coating, the bioavailability of some drugs can be increased by controlling the release of the active ingredient in the intestine. The bioavailability of some active ingredients is better in the intestine than in the stomach.

Due to its chemical structure, HPMC-P (or HP) has hydrophobic phthalyl groups that make it gastro-resistant. The solubility of the HPMC-P can be adjusted depending on the phthalyl group content.

SEPPIC distributes a HPMC-P range that meets the needs of pharmaceutical specialists, with dissolution pHs ranging from pH 5.0 to 5.5. These characteristics allow HPMC-P to be used in controlled release forms in order to target the drug at a specific site.

In addition to different dissolution pHs, HPMC-P also exists at different viscosities, which means that it can be used with liquid or lower viscosity formulations.

Product range

HP is mainly characterised by viscosity but especially by its dissolution pH.

These two parameters are critically important for controlled release applications for active pharmaceutical ingredients. The entire HPMCP range has a particle size of 1mm.

Grade Phtalyl content (%) pH solubility Viscosity (cP)
HP-50 24 5 55

31 5.5 40



There are 2 grades of HP, HP-50 and HP-55, where the dissolution pHs are 5.0 and 5.5 respectively.

A specific grade, HP-55S (derived from HP-55) which has a higher molecular weight and a greater film strength can also be offered.

The products in the HP range are manufactured in accordance with the Good Manufacturing Practices applicable to excipients.

All the regulatory and quality documents required for registration are available on request.


The Japanese company SHIN ETSU is a leader in cellulose chemistry.

SHIN ETSU develops pharmaceutical excipients and particularly cellulosic polymers for a range of applications such as film-coating, compression and matrices.

SEPPIC™ distributes SHIN ETSU products in Western and Southern Europe and several other countries.


Safety Data Sheet


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