Agomelatine Acid Radical Complex Solubility and Purity

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Solution Overview

Problem

Current methods for producing Agomelatine fail to achieve a stable acid radical complex with high purity, defined crystallographic form, and improved solubility, which are crucial for pharmaceutical formulations.

Innovation Solution

The formation of Agomelatine acid radical complexes through reactions with specific acids like sulfuric acid and methanesulfonic acid, utilizing hydrogen bonding to create stable complexes, is achieved by dissolving Agomelatine in an organic solvent, adding the corresponding acid, and crystallizing or precipitating the product, followed by washing and drying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If Agomelatine is reacted with common acids to form complexes, then solubility may be improved, but the purity, crystallographic form definition, and reproductivity deteriorate

Engineering Contradiction:
ImprovesolubilityVSAvoidpurity and crystallographic form definition
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by carefully controlling reaction temperature (0-25°C), acid-to-agomelatine ratios (1:1 to 3:1), solvent types (dichloromethane, chloroform, acetone, alcohols), and pH values (2-4) to achieve optimal complex formation. These parameter optimizations enable simultaneous achievement of high solubility improvement while maintaining high purity (>98%), defined crystallographic forms, and excellent reproductivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses organic solvents as intermediaries to facilitate the reaction between Agomelatine and acids. The solvents (dichloromethane, chloroform, acetone, C1-C4 alcohols) mediate the complex formation process, enabling controlled reaction conditions that produce high-purity complexes with defined crystal structures while improving solubility

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If Agomelatine is reacted with specific acids to form stable complexes, then purity and reproductivity are improved, but the complexity of the preparation process increases

Engineering Contradiction:
Improvepurity and reproductivityVSAvoidpreparation process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-dissolving Agomelatine in organic solvents before adding acids, and pre-preparing acid solutions in specific solvents. This preliminary preparation ensures homogeneous mixing and controlled reaction conditions, leading to high purity complexes with consistent crystallographic forms while maintaining relatively simple操作流程

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent optimizes reaction parameters including temperature (0-25°C), acid ratios (1:1 to 3:1), solvent selection, and pH control (2-4) to achieve high purity and reproductivity. These parameter optimizations enable the process to maintain simplicity while achieving excellent manufacturing precision

Inventive Principle:
Principle #35Parameter changes

3Productivity

If reaction temperature is increased to improve reaction speed, then productivity is improved, but the quality of crystal formation and yield deteriorate

Engineering Contradiction:
Improvereaction speedVSAvoidcrystal quality and yield
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes reaction temperature parameters within the range of 0-25°C, with preferred temperatures of 0-10°C for sulfuric acid complexes and 10-25°C for methanesulfonic acid complexes. This temperature optimization achieves the best balance between reaction speed, crystal quality, and yield, with yields reaching 90-98%

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 resulting Agomelatine acid radical complexes exhibit enhanced purity, reproducibility, and solubility, making them more suitable for pharmaceutical preparations and improving bioavailability.

Implementation Method 1

the Agomelatine compound can react with specific acids containing sulfur, oxygen (HX = H2SO4, CH3SO3H), forming stable complex via hydrogen bond

Methodology Applied
Scientific EffectHydrogen bonding: Hydrogenation

Implementation Method 2

dissolving Agomelatine in an organic solvent before adding the corresponding HX acid

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

crystallizing or precipitating out the product after reaction

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 4

crystallizing or precipitating out the product after reaction

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 5

washing and drying the crystallization or precipitation product

Methodology Applied
Scientific EffectWashing:

Implementation Method 6

washing and drying the crystallization or precipitation product

Methodology Applied
Scientific EffectDrying: Desiccation

Data Source

PatentEP2851363B1Agomelatine acid radical composite, and preparation method and application thereof
Publication Date: 2018.01.03 SHANGHAI RIGHTHAND PHARMTECH
  • EP2851363B1 patent drawingFigure 1
  • EP2851363B1 patent drawingFigure 2
  • EP2851363B1 patent drawingFigure 3

AI summary

The present invention relates to an Agomelatine acid radical complex in formula (I) and the preparation method thereof (HX = H2SO4, RSO3H (R = CH3, Ph, 4-CH3Ph)). The solubility of the Agomelatine acid radical complex obtained by the method of the present invention is significantly improved compared with Agomelatine, has good stability and higher purity, and is suitable for application in finished-product medicinal preparations. The preparation process is quite simple, and a product with high purity can be obtained without special operations. (HX = H2SO4, RSO3H(R= CH3, Ph or 4-CH3Ph)).