Method for preparing low-substituted hydroxypropyl cellulose

Abstract

The invention provides a method for preparing low-substituted hydroxypropyl cellulose and belongs to the technical field of pharmacy. According to the method provided by the invention, a ketone or alcohol solvent is used as a reaction solvent; reaction conditions and a post-treatment mode are controlled; the solvent recovered after reaction is detected to confirm the content of components contained in the solvent and then is reused, thereby recycling the solvent without distillation and rectification. The method provided by the invention is simple, can reduce production cost and therefore is favorable to industrial production.

Description

technical field

[0001] The invention relates to a preparation method of low-substituted hydroxypropyl cellulose, which belongs to the technical field of pharmacy. Background technique

[0002] Low-substituted hydroxypropyl cellulose (L-HPC) is an important auxiliary material commonly used in tablet disintegrants and binders. It is easy to compress and form, and has strong applicability; Tablets, adding low-substituted hydroxypropyl cellulose can improve the hardness of the tablet and the brightness of the appearance, and can also make the tablet disintegrate quickly; low-substituted hydroxypropyl cellulose can also be used as an emulsifier, stabilizer, suspending agent, Thickeners, film-forming agents, etc. are used in the food industry and daily chemical industry.

[0003] At present, the preparation of low-substituted hydroxypropyl cellulose is usually prepared by alkalizing natural cellulose fibers under the action of water and alkali, and then reacting with propylene ox...

Examples

specific Embodiment approach

[0053] In order to enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting examples are further disclosed below to further describe the present invention in detail.

[0054] The reagents used in the present invention can be purchased from the market or can be prepared by the methods described in the present invention.

[0055] In the present invention, g means gram, and mL means milliliter.

Embodiment 1

[0057] Add 600 mL of acetone, 40 g of refined cotton, and 80 g of 15% (mass fraction) sodium hydroxide solution into the reactor, stir, and alkalize at 30° C. for 2 hours. Add 27mL of propylene oxide and heat up to 56°C for etherification for 13 hours; press filter to collect the solid and liquid respectively. The filter cake was dispersed in a solution containing 18 mL of glacial acetic acid and 800 mL of water, and stirred for 1 hour. Pressure filtration, the obtained solid was washed with 200 mL of water; then the solid was mixed with 500 mL of water, beaten and stirred at 80 ° C for 40 minutes, press filtered, washed with 200 mL of water, the obtained solid was vacuum dried at 90 ° C for 24 hours, and 39.2 g of the product white powder was obtained; The relevant method in the current "Chinese Pharmacopoeia" detects the content of hydroxypropoxyl, which is 10.35%.

Embodiment 2

[0059] Example 1 Pressure filtration obtained liquid solvent 500mL, after testing, contained acetone 472mL, propylene oxide 11.1mL, water 25.5g, added 128mL acetone, transferred to the reactor, and stirred. Add 40 g of refined cotton and 54.5 g of 22% (mass fraction) sodium hydroxide solution, and alkalize at 25° C. for 3 hours. Add 15.8mL of propylene oxide, heat up to 60°C for etherification for 11 hours; press filter to remove acetone; disperse the filter cake in a solution containing 18mL of glacial acetic acid and 800mL of water, and stir for 0.5 hour. Pressure filtration, the obtained solid was washed with 200mL of water; then the solid was mixed with 500mL of water, beaten and stirred at 70°C for 1 hour, press filtered, the obtained solid was washed with 200mL of water, and the obtained product was vacuum-dried at 90°C for 24 hours to obtain 39.32g of the product white powder The obtained product detects the hydroxypropoxyl content according to the relevant method in th...

technical field

[0001] The invention relates to a preparation method of low-substituted hydroxypropyl cellulose, which belongs to the technical field of pharmacy. Background technique

[0002] Low-substituted hydroxypropyl cellulose (L-HPC) is an important auxiliary material commonly used in tablet disintegrants and binders. It is easy to compress and form, and has strong applicability; Tablets, adding low-substituted hydroxypropyl cellulose can improve the hardness of the tablet and the brightness of the appearance, and can also make the tablet disintegrate quickly; low-substituted hydroxypropyl cellulose can also be used as an emulsifier, stabilizer, suspending agent, Thickeners, film-forming agents, etc. are used in the food industry and daily chemical industry.

[0003] At present, the preparation of low-substituted hydroxypropyl cellulose is usually prepared by alkalizing natural cellulose fibers under the action of water and alkali, and then reacting with propylene ox...

Examples

specific Embodiment approach

[0053] In order to enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting examples are further disclosed below to further describe the present invention in detail.

[0054] The reagents used in the present invention can be purchased from the market or can be prepared by the methods described in the present invention.

[0055] In the present invention, g means gram, and mL means milliliter.

Embodiment 1

[0057] Add 600 mL of acetone, 40 g of refined cotton, and 80 g of 15% (mass fraction) sodium hydroxide solution into the reactor, stir, and alkalize at 30° C. for 2 hours. Add 27mL of propylene oxide and heat up to 56°C for etherification for 13 hours; press filter to collect the solid and liquid respectively. The filter cake was dispersed in a solution containing 18 mL of glacial acetic acid and 800 mL of water, and stirred for 1 hour. Pressure filtration, the obtained solid was washed with 200 mL of water; then the solid was mixed with 500 mL of water, beaten and stirred at 80 ° C for 40 minutes, press filtered, washed with 200 mL of water, the obtained solid was vacuum dried at 90 ° C for 24 hours, and 39.2 g of the product white powder was obtained; The relevant method in the current "Chinese Pharmacopoeia" detects the content of hydroxypropoxyl, which is 10.35%.

Embodiment 2

[0059] Example 1 Pressure filtration obtained liquid solvent 500mL, after testing, contained acetone 472mL, propylene oxide 11.1mL, water 25.5g, added 128mL acetone, transferred to the reactor, and stirred. Add 40 g of refined cotton and 54.5 g of 22% (mass fraction) sodium hydroxide solution, and alkalize at 25° C. for 3 hours. Add 15.8mL of propylene oxide, heat up to 60°C for etherification for 11 hours; press filter to remove acetone; disperse the filter cake in a solution containing 18mL of glacial acetic acid and 800mL of water, and stir for 0.5 hour. Pressure filtration, the obtained solid was washed with 200mL of water; then the solid was mixed with 500mL of water, beaten and stirred at 70°C for 1 hour, press filtered, the obtained solid was washed with 200mL of water, and the obtained product was vacuum-dried at 90°C for 24 hours to obtain 39.32g of the product white powder The obtained product detects the hydroxypropoxyl content according to the relevant method in th...