Levodopa refining method

A technology of levodopa and phenol, which is applied in the field of medicine, can solve the problems of lack of levodopa purity and interaction effects, and achieve the effects of strong selectivity, improved quality, and high purity of fine products

Active Publication Date: 2019-03-19
GUANGXI INST OF CHINESE MEDICINE & PHARMA SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the purity of the produced levodopa is often not up to the standards for export to the United States or the European Union, and tyrosine will interact with certain drugs such as levodopa and antidepressants

Method used

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  • Levodopa refining method

Examples

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Effect test

Embodiment 1

[0026] A method for refining levodopa, the steps are:

[0027] (1) Preparation of extraction solution: Take phenol and water, mix them according to the weight ratio of 1:3, heat to 70°C to make them miscible, and obtain the extraction solution;

[0028] (2) Dissolution: Take the crude product of levodopa, add 3 times the weight of the extract, dissolve it to saturation at 70°C, let it stand for 40 minutes, and then filter it at 65°C;

[0029] (3) Impurity removal: take the filtrate to cool, precipitate levodopa and phenol, and filter the precipitate;

[0030] (4) Phenol removal: take the precipitate obtained in step (3), add absolute ethanol 5 times its weight, dissolve the phenol and remove it to obtain levodopa solids;

[0031] (5) Recrystallization: Take the solid levodopa, add 8 times its weight of hydrochloric acid with a mass fraction of 0.05 mol / L, adjust the pH to 1.5, heat to boiling, add the solid levodopa to dissolve to saturation, put Cool to make levodopa crysta...

Embodiment 2

[0033] A method for refining levodopa, the steps are:

[0034] (1) Preparation of extraction solution: Take phenol and water, mix them according to the weight ratio of 1:4, heat to 68°C to make them miscible, and obtain the extraction solution;

[0035] (2) Dissolution: Take the crude product of levodopa, add 5 times its weight in the extract, dissolve it to saturation at 68°C, let it stand for 50 minutes, and then filter it at 68°C;

[0036] (3) Impurity removal: take the filtrate to cool, precipitate levodopa and phenol, and filter the precipitate;

[0037] (4) Phenol removal: Take the precipitate obtained in step (3), add 7 times its weight in absolute ethanol, dissolve the phenol and remove it to obtain levodopa solids, and repeat this operation again;

[0038] (5) Recrystallization: Take the solid levodopa, add 6 times its weight of hydrochloric acid with a mass fraction of 0.1 mol / L, adjust the pH to 1.2, heat to boiling, add the solid levodopa to dissolve to saturation, ...

Embodiment 3

[0040] A method for refining levodopa, the steps are:

[0041] (1) Preparation of extraction solution: Take phenol and water, mix them according to the weight ratio of 1:5, heat to 65°C to make them miscible, and obtain the extraction solution;

[0042] (2) Dissolution: Take the crude product of levodopa, add 4 times its weight in the extract, dissolve it to saturation at 65°C, let it stand for 60 minutes, and then filter it at 70°C;

[0043] (3) Impurity removal: take the filtrate to cool, precipitate levodopa and phenol, and filter the precipitate;

[0044] (4) Phenol removal: Take the precipitate obtained in step (3), add absolute ethanol 8 times its weight, dissolve the phenol and remove it to obtain levodopa solids, repeat this operation twice;

[0045] (5) Recrystallization: Take the solid levodopa, add 6 times its weight of hydrochloric acid with a mass fraction of 0.12 mol / L, adjust the pH to 1.0, heat to boiling, add the solid levodopa to dissolve to saturation, put ...

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Abstract

The invention discloses a levodopa refining method. The levodopa refining method comprises the following steps of (1) leaching liquor preparation, (2) dissolution, (3) impurity removal, (4) phenol removal and (5) recrystallization to obtain refined levodopa. According to the levodopa refining method, a prepared leaching liquor can fully dissolve levodopa and impurities; separating the levodopa through crystallization can help remove most of the impurities to ensure the quality of levodopa finished products and meanwhile to provide a good environment for subsequent tyrosine removal, thereby ensuring that tyrosine can be thoroughly removed. The prepared refined levodopa achieves a purity degree not lower than 99%, and when detected through a USP (United States Pharmacopeia) 38 method, has acontent of tyrosine not higher than 0.1%.

Description

technical field [0001] The invention relates to the technical field of medicine, in particular to a method for refining levodopa. Background technique [0002] Levodopa (3,4-Dihydrox ylphenylalanine, L-Dopa) belongs to phenylalanine compounds and is currently the most commonly used in the treatment of primary parkinsonism and non-pharmaceutical parkinsonism. Effective medicine, it is one of the main effective active ingredients of Maodou and Lidou. White or off-white crystalline powder, chemical name: 3-hydroxy-L-tyrosine, molecular formula: C 9 h 11 NO 4 , molecular weight: 197.19, English name: Levodopa, CAS accession number: 59-92-7, EINECS number: 200-445-2. Levodopa is an amphoteric amino acid with an isoelectric point of 3.5. It is easily soluble in dilute acid, slightly soluble in aqueous solution with pH>3.5, and insoluble in ethanol, ether and chloroform. Levodopa is currently one of the effective drugs for the treatment of parkinsonism, and it is one of the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C227/42C07C227/40C07C229/36
CPCC07C227/40C07C227/42C07C229/36
Inventor 黄艳李学坚赵小超刘布鸣
Owner GUANGXI INST OF CHINESE MEDICINE & PHARMA SCI
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