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Precipitation modifying method for cellulose type solid enteric coatings

An enteric coating material, cellulose technology, applied in the field of polymer chemistry, can solve the problems of unsuitability for industrial production, high free acid content, large pollution, etc., to shorten the preparation period, simplify the reaction process, and be easy to operate. Effect

Inactive Publication Date: 2008-07-23
BEIJING INSTITUTE OF TECHNOLOGYGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since hydroxypropyl methylcellulose trimellitate does not precipitate in the system, there will be more serious agglomeration during washing with a large amount of purified water, resulting in a higher content of free acid
Adding concentrated hydrochloric acid in the later stage will cause greater pollution and is not suitable for industrial production

Method used

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  • Precipitation modifying method for cellulose type solid enteric coatings

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Add 80 g of glacial acetic acid, 24 g of phthalic anhydride, and 16 g of sodium acetate into a 500 ml three-neck flask with a stirring rod. Stir and warm to 65°C. Then 20 g of hydroxypropylmethylcellulose (60HD10) were added slowly. The mixture was heated to 83.5°C and stirred for 3.5h to complete esterification. After the esterification reaction, slowly add 80 g of 15% diluent of acetic acid and a mixed solution of 0.5 g of hydrogen peroxide. Then cool down to 30°C within 40 minutes. Slowly add 75g of purified water into the system, stir evenly, precipitate product particles, and dry to obtain the product.

[0032] 1) Compare the self-made product with Japan Shin-Etsu HP-55 as follows:

[0033] Adopt sodium hydroxide standard solution titration method to measure its esterification rate and free acid content: homemade HPMCP esterification rate is 31.05%, free acid content is 0.17%; Shin-Etsu HP-55 esterification rate is 31.05%, free acid content 0.17%;

[0034] 2)...

Embodiment 2

[0042] Add 80 g of glacial acetic acid, 30 g of trimellitic anhydride, and 20 g of sodium acetate in a 500 ml three-necked flask with a stirring bar. Stir and warm to 65°C. Then 20 g of hydroxypropylmethylcellulose (60HD5) were added slowly. The mixture was heated to 88.5°C and stirred for 5h for complete esterification. After the esterification reaction, slowly add 80 g of 15% diluent of acetic acid and a mixed solution of 0.5 g of hydrogen peroxide. Then cool down to 30°C within 40 minutes. Slowly add 90g of purified water into the system, stir evenly, precipitate product particles, and dry to obtain the product.

[0043]1) The esterification rate and free acid content of the synthesized HPMCT product were measured by sodium hydroxide standard solution titration method, and the results were: the esterification rate was 34.52%, and the free acid content was 0.34%.

[0044] 2) The properties of the synthesized HPMCT products are shown in Table 3.

[0045] Table 3. Common ...

Embodiment 3

[0053] Add 80 g of glacial acetic acid, 2.5 g of butyric anhydride, 10 g of acetic anhydride, and 20 g of sodium acetate into a 500 ml three-necked flask with a stirring rod. Stir and warm to 65°C. Then 20 g of hydroxypropylmethylcellulose (60HD10) were added slowly. The mixture was heated to 83.5°C and stirred for 3.5h to complete esterification. After the esterification reaction, slowly add 80 g of 15% diluent of acetic acid and a mixed solution of 0.5 g of hydrogen peroxide. Then cool down to 30°C within 40 minutes. Slowly add 100g of purified water to the system, stir evenly, precipitate product particles, and dry to obtain the product. The esterification rate and free acid content of the synthesized HPMCAS product were measured by sodium hydroxide standard solution titration method, and the results showed that the succinyl group content was 16.22%, and the acetyl group content was 7.98%. Free acid content 0.34%.

[0054] 1) The properties of the synthesized HPMCAS pr...

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Abstract

The invention relates to an improved precipitation method for the cellulose-based solid enteric-coating material; wherein, the solid enteric-coating material comprises a series of cellulose ether esters such as hydroxypropyl methylcellulose of phthalate ester (HPMCP), hydroxypropyl methylcellulose of acetic acid succinate (HPMCAS) and hydroxypropyl methylcellulose of trimellitic ester. The improved precipitation method is characterized in that the mixed solution of diluent and bleaching agent with a certain quantity is added in the reaction system at the later reaction phase, then the product is enabled to form even powdery particles in the viscous system via cooling and adding purified water for continuous precipitation. The improved precipitation method for the cellulose-based solid enteric-coating material has the advantages that the content of free acid in the product is greatly reduced; the dense and powdery particles do not need to be grinded; and dissolution rate of the product is improved to a great extent.

Description

technical field [0001] The invention belongs to a method for improving precipitation of cellulose-based solid enteric-coating materials, and more precisely relates to a method for making cellulose-based solid enteric-coating materials form uniform and compact powder particles. It belongs to the field of polymer chemistry technology, and its national patent classification number is XXX. Background technique [0002] The solid enteric coating material introduces some ester groups on the macromolecular chain of cellulose, so that at least one ester group of the cellulose derivative is attached to the glucose ring. By changing the ratio of ester groups, it can be dissolved in buffer solutions with different pH values, so it has special pH-sensitive characteristics. The main use is to keep the drug intact in the harsh environment of the stomach, yet release it rapidly when the drug reaches the intestine. Solid enteric coating materials play a key role in the practical applicati...

Claims

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Application Information

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IPC IPC(8): C08B11/20C08K3/18
Inventor 邵自强孟玲铃王文俊李永红田武
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
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