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PRODUCTION OF HYDROXYPROPYL METHYL CELLULOSE ACETATE SUCCINATE (HPMCAS)

IP.com Disclosure Number: IPCOM000249778D
Publication Date: 2017-Apr-03
Document File: 1 page(s) / 85K

Publishing Venue

The IP.com Prior Art Database

Abstract

Hydroxypropyl methyl cellulose acetate succinate (HPMCAS) is a cellulose ether ester which can be obtained by reacting hydroxypropyl methyl cellulose (HPMC) with succinic anhydride, acetic anhydride and sodium acetate in glacial acetic acid to HPMCAS. Glacial acetic acid acts as a solvent. Sodium acetate acts as a base and deprotonates the free hydroxyl groups of HPMC, which is a requirement for further esterification of these hydroxyl groups. The reaction temperature is typically about 80 – 90 °C, the reaction times are 30 min. – 3.5 hours. A commonly used HPMC has a methoxyl content of 28-30 %, a hydroxypropyl content of 7–12 % and a viscosity of about 3 mPa-s, measured as a 2% solution in water.

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PRODUCTION OF HYDROXYPROPYL METHYL CELLULOSE ACETATE

SUCCINATE (HPMCAS)

Hydroxypropyl methyl cellulose acetate succinate (HPMCAS) is a cellulose ether ester

which can be obtained by reacting hydroxypropyl methyl cellulose (HPMC) with succinic

anhydride, acetic anhydride and sodium acetate in glacial acetic acid to HPMCAS. Glacial

acetic acid acts as a solvent. Sodium acetate acts as a base and deprotonates the free hydroxyl

groups of HPMC, which is a requirement for further esterification of these hydroxyl groups.

The reaction temperature is typically about 80 – 90 °C, the reaction times are 30 min. – 3.5

hours. A commonly used HPMC has a methoxyl content of 28-30 %, a hydroxypropyl content

of 7–12 % and a viscosity of about 3 mPas, measured as a 2% solution in water.

According to one procedure all starting materials are mixed at room temperature and

then heated up to the desired reaction temperature for at least 2 hours.

Another process is to add succinic anhydride and acetic anhydride to glacial acetic acid

at 50-60 °C, to add sodium acetate and HPMC and to react the mixture for 1 – 2 hours.

Another process is to pre-dissolve the HPMC with sodium acetate in glacial acetic acid

at 80 – 85 °C, followed by addition of only succinic anhydride and letting the mixture react

for 2 - 2.5 hours, then followed by addition of acetic anhydride and letting the mixture further

react.

Another process is to pre-dissolve the HPMC with sodium acetate in glacial acetic acid

at 80 – 85 °C, f...