Agomelatine Amorphous Dispersion via Hot-Melt Granulation

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Solution Overview

Problem

Agomelatine's poor solubility in acidic and buffered solutions leads to low bioavailability and difficulties in preparation, particularly due to its insolubility in hydrochloric acid, acetate buffer, phosphate buffer, and water, which complicates its dissolution and absorption in pharmaceutical formulations.

Innovation Solution

A method involving hot-melt granulation of agomelatine with cross-linked polyvinylpolypyrrolidone, where agomelatine is melted and dispersed within the pores of PVPP, maintaining an amorphous state through the network structure, inhibiting crystallization and enhancing solubility, without the need for mechanical pulverization or airflow crushing, using a suitable weight ratio of PVPP to agomelatine (2:1 to 10:1) and appropriate heating temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If agomelatine is micronized to smaller particle size to enhance dissolution, then dissolution rate is improved, but production complexity increases and production efficiency decreases

Engineering Contradiction:
Improveparticle size controlVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the physical state parameter of agomelatine from crystalline to amorphous form through hot-melt granulation. This parameter change enhances dissolution rate without requiring precise particle size control, thereby avoiding the need for complex micronization equipment and processes while maintaining high production efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition by melting agomelatine and then rapidly cooling it to form amorphous solid dispersion. This phase transition approach achieves enhanced dissolution without mechanical particle size reduction, eliminating the need for airflow crushers and complex production procedures

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If amorphous form of agomelatine is used to improve solubility, then dissolution rate is enhanced, but stability decreases due to transformation into crystalline state

Engineering Contradiction:
Improvedissolution rateVSAvoidcrystal form stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent introduces cross-linked polyvinylpolypyrrolidone as an intermediary carrier material. This amorphous matrix acts as a stabilizing medium that physically restrains agomelatine molecules, preventing their reorganization into crystalline structures during storage, thereby maintaining both high dissolution rate and long-term stability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite material system consisting of amorphous agomelatine dispersed in cross-linked polyvinylpolypyrrolidone matrix. This composite structure combines the high solubility of amorphous form with the structural stability of the cross-linked polymer network, achieving both enhanced dissolution and improved stability

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If hot-melt granulation is used to maintain amorphous form, then dissolution and stability are improved, but process complexity increases

Engineering Contradiction:
Improveamorphous form maintenanceVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the granulation process with the amorphization process by conducting hot-melt granulation directly. This combines multiple functions (granulation, amorphous formation, and dispersion) into a single integrated process step, reducing overall process complexity despite the advanced functionality achieved

Inventive Principle:
Principle #5Merging (Combining)

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

This method ensures stable amorphous form of agomelatine, maintaining high dissolution rates and bioavailability, simplifies the preparation process, reduces production costs, and results in a stable solid preparation with improved in vitro dissolution properties, suitable for industrial production.

Implementation Method 1

Since agomelatine is adsorbed by the cross-linked polyvinylpolypyrrolidone after being melted, the intermolecular distance increases, and amorphous form of agomelatine is obtained after cooling

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

agomelatine is melted and dispersed in the form of fluid into the pores of the cross-linked polyvinylpolypyrrolidone

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the crystallization of agomelatine is inhibited due to the separation effect of the network molecular structure of the cross-linked polyvinylpolypyrrolidone

Methodology Applied
Scientific EffectSeparation effect:

Data Source

PatentEP2902015B1Preparation method of agomelatine solid preparation
Publication Date: 2019.12.04 ZHEJIANG HUAHAI PHARMACEUTICAL CO LTD
  • EP2902015B1 patent drawingFigure 1~2
  • EP2902015B1 patent drawingFigure 3
  • EP2902015B1 patent drawing

AI summary

A preparation method of an agomelatine solid preparation comprises: mixing agomelatine or pharmaceutically acceptable salts with cross-linked polyvinylpolypyrrolidone; hot-melting the mixture to prepare particles; and then mixing the particles with other pharmaceutically acceptable carriers to be tableted or filled to form capsules. The agomelatine solid preparation prepared by the method is stable and controllable in quality and quick in dissolution.