Polymorph Crystallization Solvent Selection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing methods for producing 3-(4-amino-1-oxo-1,3-dihydro-2H-isoindole-2-yl)-piperidine-2,6-dione face challenges such as poor solubility in solvents, requiring excessive amounts of solvent, instability in acidic conditions, and the use of harmful organic solvents, which complicates industrial production and affects the product's appearance and stability.

Innovation Solution

New polymorphic forms of 3-(4-amino-1-oxo-1,3-dihydro-2H-isoindole-2-yl)-piperidine-2,6-dione are developed with improved solubility and stability, using a method that involves dissolving the compound in dimethylformamide or dimethylsulfoxide with a high solvent-to-drug ratio, followed by addition of water or a mixed solvent system, and slow cooling to precipitate crystalline solids, reducing the need for harmful solvents and enhancing product stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the compound is dissolved in water or organic solvents by heating, then the compound can be crystallized upon cooling, but a large amount of solvent (over 100 times) is needed due to practical insolubility

Engineering Contradiction:
Improvecrystallization reliabilityVSAvoidsolvent amount
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the solvent system parameters by using dimethylformamide or dimethylsulfoxide as primary solvents instead of water or conventional organic solvents. These solvents provide appropriate solubility characteristics that allow crystallization with much smaller solvent-to-drug ratios, resolving the contradiction between reliable crystallization and excessive solvent usage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dimethylformamide or dimethylsulfoxide as intermediary solvents that facilitate the dissolution and subsequent crystallization of the compound. These intermediary solvents act as mediators between the poorly soluble compound and the final crystalline product, enabling the process to proceed with reduced solvent quantities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional solvents are used for crystallization, then the compound can be purified, but the appearance and color cannot be improved from light yellow to white or off-white

Engineering Contradiction:
Improveproduct appearance qualityVSAvoidcrystallization process simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the solvent parameters by selecting dimethylformamide or dimethylsulfoxide, which have specific solubility and boiling point characteristics that enable the compound to crystallize in a white or off-white form. This parameter change directly addresses the appearance quality issue while maintaining process simplicity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If harmful organic solvents (e.g., toluene, acetonitrile) are used, then the compound can be dissolved and crystallized, but residual solvent in the product may have negative effects on human body

Engineering Contradiction:
Improvecrystallization reliabilityVSAvoidtoxicity of residual solvent
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces harmful organic solvents with dimethylformamide or dimethylsulfoxide, which are more suitable for pharmaceutical applications. These alternative solvents can be more easily removed or are less toxic, thereby reducing the harmful effects of residual solvent in the final product while maintaining crystallization reliability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent introduces dimethylformamide or dimethylsulfoxide as intermediary solvents that facilitate the crystallization process without leaving harmful residues. These intermediary substances serve as safer alternatives to conventional harmful organic solvents, reducing toxicity concerns while maintaining process effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If the compound is stirred for long time in slurrying system, then crystal transformation can occur, but the appearance, color and luster cannot be improved

Engineering Contradiction:
Improvepolymorph stabilityVSAvoidproduct appearance quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent changes the solvent parameters to dimethylformamide or dimethylsulfoxide, which enable the compound to crystallize directly in the desired polymorphic form with improved appearance. This eliminates the need for prolonged stirring and crystal transformation, simultaneously achieving polymorph stability and superior product appearance.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The new polymorphic forms exhibit improved chemical and physical stability, reduced solvent usage, and better controllability in industrial production, leading to higher-quality products with enhanced stability and reduced toxicity risks.

Implementation Method 1

dissolving the compound in dimethylformamide or dimethylsulfoxide

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 2

addition of water or a mixed solvent system, and slow cooling to precipitate crystalline solids

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 3

slow cooling to precipitate crystalline solids

Methodology Applied
Scientific EffectCrystallisation: Crystallisation

Data Source

PatentEP2496568B1Polymorph of 3-(substituteddihydroisoindolinone-2-yl)-2,6-dioxopiperidine, and pharmaceutical compositions thereof
Publication Date: 2017.04.26 NANJING CAVENDISH BIO ENGINEERING TECHNOLOGY CO LTD
  • EP2496568B1 patent drawingFigure 1
  • EP2496568B1 patent drawingFigure 2
  • EP2496568B1 patent drawingFigure 3-1

AI summary

The present invention provides polymorph of 3-(4-amino-1-oxo-1,3- dihydro-2H-isoindole-2-yl)-piperidine-2,6-dione, and also the preparing methods and pharmaceutical compositions thereof.