Amorphous Solid Solutions for Poorly Soluble Drugs

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for incorporating poorly water-soluble substances into formulations fail to achieve stable and high active ingredient loading, particularly in achieving an amorphous state, and often result in sticky, viscous polymers that are not suitable for processing.

Innovation Solution

A process involving the radical polymerization of a mixture comprising 30-80% N-vinyl lactam, 10-50% vinyl acetate, and 10-50% polyether, with embedding at temperatures above the melting point of the substances, using preferred compositions of 30-70% N-vinyl lactam, 15-35% vinyl acetate, and 10-35% polyether, to form copolymers that are then extruded with active ingredients, resulting in stable, amorphous solid solutions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If known polymeric solubilizers are used to solubilize poorly water-soluble substances, then solubilization capability is provided, but stable solid solutions are not formed and the active ingredient crystallizes during storage

Engineering Contradiction:
Improvestability of solid solutionVSAvoidamorphous state maintenance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical composition parameters of the polymer by incorporating specific ratios of N-vinyl lactam (30-80%), vinyl acetate (10-50%), and polyether (10-50%) units. This compositional parameter change creates a polymer matrix with optimized glass transition temperature and molecular mobility, preventing crystallization of the active ingredient while maintaining solubilization capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite solid solution system where the active ingredient is molecularly dispersed within the copolymer matrix. The composite structure combines the solubilization properties of polyether units with the structural stability provided by N-vinyl lactam and vinyl acetate units, achieving both solubilization and crystallization prevention.

Inventive Principle:
Principle #40Composite materials

2Reliability

If graft polymers containing polyalkylene oxide are used as solubilizers, then solubilization is achieved, but the polymers are viscous and sticky liquids that are not suitable for processing

Engineering Contradiction:
Improvesolubilization capabilityVSAvoidprocessability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the physical state parameter by adjusting the polymer composition to achieve a glass transition temperature above ambient temperature. The specific ratio of rigid N-vinyl lactam and vinyl acetate units to flexible polyether units creates a solid, free-flowing powder with reduced viscosity and improved processability while retaining solubilization functionality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polymer structure combining rigid structural units (N-vinyl lactam, vinyl acetate) with flexible solubilizing units (polyether). This composite architecture provides both the solubilization capability of polyether-containing polymers and the processability of solid materials, eliminating the viscous liquid problem.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If embedding is carried out at temperatures below the melting point of the active ingredient, then the polymer can be processed, but stable amorphous solid solutions with high active ingredient loading cannot be achieved

Engineering Contradiction:
Improveprocessing capabilityVSAvoidactive ingredient loading
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent utilizes the phase transition of the polymer matrix by heating above the melting point of the active ingredient during extrusion, then rapidly cooling to trap the active ingredient in an amorphous state within the polymer matrix. This phase transition approach enables high active ingredient loading while maintaining stability and preventing crystallization during storage.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent changes the temperature parameter during processing to exceed the active ingredient melting point, enabling complete mixing and molecular dispersion. The subsequent rapid cooling rate parameter change prevents crystallization, achieving stable amorphous solid solutions with high active ingredient concentrations.

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

This process enables the production of stable, amorphous solid solutions with high active ingredient loading, preventing crystallization and providing free-flowing, water-soluble powders suitable for pharmaceutical and cosmetic applications.

Implementation Method 1

the substances being amorphous in the extruded preparation

Methodology Applied
Scientific EffectAmorphous state:

Implementation Method 2

An important requirement for such solid solutions is that they are stable even when stored over a long period of time, i.e. that the active ingredient does not crystallize

Methodology Applied
Scientific EffectCrystallization prevention: Crystallisation

Implementation Method 3

which are obtained by radically initiated polymerization of a mixture of i) 30 to 80% by weight of N-vinyl lactam, ii) 10 to 50% by weight of vinyl acetate and iii) 10 to 50% by weight of a polyether

Methodology Applied
Scientific EffectRadical polymerization:

Implementation Method 4

the embedding takes place at temperatures above the melting point of the biologically active substances

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 5

Embedding is carried out by extrusion

Methodology Applied
Scientific EffectExtrusion: Extrusion

Data Source

PatentEP2413907B1Method for producing preparations of substances poorly soluble in water
Publication Date: 2014.10.01 BASF SE

AI summary

The invention relates to a method for producing preparations of substances poorly soluble in water, wherein the poorly soluble substances are present amorphously embedded in a copolymer, and the copolymer is obtained by radically initiated polymerization of a mixture of i) 30 to 80 wt% N-vinyl lactam, ii) 10 to 50 wt% vinyl acetate, and iii) 10 to 50 wt% of a polyether, with the stipulation that the sum of the components i), ii), and iii) is equal to 100 wt%, wherein the embedding of the poorly soluble substance into the copolymer occurs at temperatures above the melting point of the poorly soluble substances.