Method for separating and preparing trace impurity in etodolac bulk drug

Abstract

The invention discloses a method for separating and preparing a trace impurity in an etodolac bulk drug. The molecular formula of the trace impurity is C29H34N2O3, and the trace impurity in the etodolac bulk drug is separated and prepared by adopting a gradient elution high-speed counter-current chromatography. A solvent system of the counter-current chromatography comprises normal hexane, ethyl acetate, ethanol and water. The elution mode is gradient elution. Online monitoring is performed through an ultraviolet detector, target fractions are collected and combined, and rotary evaporation is performed until the fractions are dry to obtain the trace impurity. The method provided by the invention enables the quality of etodolac series products to be easily controlled.

Description

technical field

[0001] The invention belongs to the technical field of drug impurity research, and in particular relates to a method for separating and preparing a trace impurity from etodolac crude drug by high-speed countercurrent chromatography. Background technique

[0002] Reagents, solvents or catalysts are often added in the pharmaceutical production process. Due to solubility, adsorption, occlusion, co-precipitation, mixed crystal formation and other reasons, it is impossible to completely remove them, resulting in the presence of related impurities in the product. If it is treated with acidic or alkaline reagents, the product may contain acidic or alkaline impurities; after extraction or refining with organic solvents, there may be residual organic solvents in the product. The Chinese Pharmacopoeia stipulates that the residual amount of harmful organic solvents (such as benzene, chloroform, 1,4-dioxane, methylene chloride, pyridine, etc.) introduced in the productio...

Examples

Embodiment 1

[0046] Embodiment 1, a kind of method that separates and prepares impurity A from etodolac bulk drug, separates impurity A from etodolac bulk drug with countercurrent chromatograph, carries out the following steps successively:

[0047] 1), preparation of two-phase solvent:

[0048] Solvent system ①: the volume ratio of normal hexane: ethyl acetate: ethanol: water = 3:2:3:2 is poured into the liquid separator after preparation to form two kinds of mutually immiscible two-phase solvents, respectively The upper and lower phases of the solvent system ①;

[0049] Solvent system ②: the volume ratio of normal hexane: ethyl acetate: ethanol: water = 2:1:2:1 is poured into the liquid separator after preparation to form two kinds of two-phase solvents that are mutually immiscible, and respectively obtain The upper and lower phases of the solvent system ②;

[0050] 2), 4ml solvent system ① upper phase and 4ml solvent system ① lower phase are mixed, get mixed solvent ①; 500mg etodolac ...

Embodiment 2-1

[0069] Embodiment 2-1, a method for separating and preparing impurity A from etodolac bulk drug:

[0070] Change the injection flow rate of the mobile phase from 5.0ml / min to 6.0ml / min in step 2) of Example 1, and the rest are the same as in Example 1. The finally obtained impurity A has a purity of 96.4% and a recovery rate of 87.7%.

Embodiment 2-2

[0071] Embodiment 2-2, a method for separating and preparing impurity A from etodolac bulk drug:

[0072] Change the injection flow rate of the mobile phase from 5.0ml / min to 4.0ml / min in step 2) of Example 1, and the rest are the same as in Example 1. The final obtained impurity A has a purity of 96.2% and a recovery rate of 85.2%.

technical field

[0001] The invention belongs to the technical field of drug impurity research, and in particular relates to a method for separating and preparing a trace impurity from etodolac crude drug by high-speed countercurrent chromatography. Background technique

[0002] Reagents, solvents or catalysts are often added in the pharmaceutical production process. Due to solubility, adsorption, occlusion, co-precipitation, mixed crystal formation and other reasons, it is impossible to completely remove them, resulting in the presence of related impurities in the product. If it is treated with acidic or alkaline reagents, the product may contain acidic or alkaline impurities; after extraction or refining with organic solvents, there may be residual organic solvents in the product. The Chinese Pharmacopoeia stipulates that the residual amount of harmful organic solvents (such as benzene, chloroform, 1,4-dioxane, methylene chloride, pyridine, etc.) introduced in the productio...

Examples

Embodiment 1

[0046] Embodiment 1, a kind of method that separates and prepares impurity A from etodolac bulk drug, separates impurity A from etodolac bulk drug with countercurrent chromatograph, carries out the following steps successively:

[0047] 1), preparation of two-phase solvent:

[0048] Solvent system ①: the volume ratio of normal hexane: ethyl acetate: ethanol: water = 3:2:3:2 is poured into the liquid separator after preparation to form two kinds of mutually immiscible two-phase solvents, respectively The upper and lower phases of the solvent system ①;

[0049] Solvent system ②: the volume ratio of normal hexane: ethyl acetate: ethanol: water = 2:1:2:1 is poured into the liquid separator after preparation to form two kinds of two-phase solvents that are mutually immiscible, and respectively obtain The upper and lower phases of the solvent system ②;

[0050] 2), 4ml solvent system ① upper phase and 4ml solvent system ① lower phase are mixed, get mixed solvent ①; 500mg etodolac ...

Embodiment 2-1

[0069] Embodiment 2-1, a method for separating and preparing impurity A from etodolac bulk drug:

[0070] Change the injection flow rate of the mobile phase from 5.0ml / min to 6.0ml / min in step 2) of Example 1, and the rest are the same as in Example 1. The finally obtained impurity A has a purity of 96.4% and a recovery rate of 87.7%.

Embodiment 2-2

[0071] Embodiment 2-2, a method for separating and preparing impurity A from etodolac bulk drug:

[0072] Change the injection flow rate of the mobile phase from 5.0ml / min to 4.0ml / min in step 2) of Example 1, and the rest are the same as in Example 1. The final obtained impurity A has a purity of 96.2% and a recovery rate of 85.2%.

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