Crystalline Active Ingredient Microparticles via Controlled Precipitation

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Solution Overview

Problem

Existing methods for producing active ingredient particles for rapid drug release suffer from issues such as amorphization, poor processability, and broad particle size distribution, which hinder the achievement of highly crystalline, stable, and uniformly sized microparticles suitable for very rapid release formulations.

Innovation Solution

A method involving the preparation of a suspension with primary particles, solvent, non-solvent, and inert shaped bodies, followed by mixing and crystallization to produce crystalline active substance microparticles with a narrow size distribution and high crystallinity, which are then dried and optionally mixed with a hydrophilic excipient for enhanced pharmaceutical processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If jet mill method is used to micronize active ingredients, then particle size is reduced to micrometer range for rapid release, but crystallinity decreases and amorphization occurs

Engineering Contradiction:
Improveparticle sizeVSAvoidcrystallinity
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The patent replaces the mechanical grinding system (jet mill) with a crystallization system that uses supersaturation and controlled nucleation to produce fine particles. The active ingredient is dissolved in a solvent, then rapidly precipitated by adding a non-solvent, causing spontaneous crystallization into fine microparticles without mechanical impact, thereby maintaining high crystallinity while achieving rapid release particle sizes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Length of moving object

If strong grinding energy input is applied to achieve finer grain size, then particle size is reduced for rapid release, but amorphization increases and stability decreases

Engineering Contradiction:
Improvegrain sizeVSAvoidstability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent exploits the phase transition from dissolved state to crystalline solid state through rapid precipitation. By dissolving the active ingredient in a solvent and then rapidly adding a non-solvent, the system undergoes a phase transition that spontaneously generates fine crystalline particles. This phase transition approach avoids mechanical energy input that would cause amorphization, while achieving the desired fine grain size for rapid release and maintaining stability through crystalline structure.

Inventive Principle:
Principle #36Phase transitions

3Length of moving object

If micronization is used to achieve rapid release, then particle size is reduced, but particle size distribution becomes broad

Engineering Contradiction:
Improveparticle sizeVSAvoidparticle size distribution
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent employs controlled periodic addition of non-solvent to the saturated solution, creating consistent nucleation events that generate uniform particle sizes. The systematic crystallization process, with controlled mixing and temperature, ensures that particles form under identical conditions, resulting in a narrow particle size distribution centered around the desired micrometer range, unlike the broad distribution from mechanical micronization.

Inventive Principle:
Principle #19Periodic action

4Length of moving object

If fine-grained micronisates are produced for rapid release, then particle size is reduced, but electrostatic charging and dust formation increase

Engineering Contradiction:
Improveparticle sizeVSAvoidelectrostatic charging
Core Design Contradiction:
Length of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent replaces mechanical impact and friction in jet mills with a gentle crystallization process. The fine microparticles form spontaneously during controlled precipitation from solution, without the high-velocity collisions and friction that generate electrostatic charging. The resulting particles have minimal static charge and reduced dust formation, while maintaining the fine particle size needed for rapid release.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 method yields highly crystalline microparticles with a narrow size distribution, ensuring rapid and complete drug release without aggregation, and improves pharmaceutical processing by avoiding electrostatic charging and dust formation, making them suitable for low-dose and ultra-low-dose applications.

Implementation Method 1

the active ingredient crystallizing out of the suspension

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 2

the active substance is crystallized from a suspension of primary particles, solvent, non-solvent and inert shaped bodies

Methodology Applied
Scientific EffectSupersaturation: Supersaturation

Data Source

PatentEP2326307B1Method for producing crystalline active ingredient microparticles
Publication Date: 2015.10.28 JESALIS PHARMA
  • EP2326307B1 patent drawingFigure 1
  • EP2326307B1 patent drawingFigure 2
  • EP2326307B1 patent drawingFigure 3

AI summary

The invention relates to a method for producing crystalline active ingredient microparticles, comprising the following steps: producing a suspension of primary particles of the active ingredient, a solution of the active ingredient, non-solvents for the active ingredient and inert molded articles, mixing the suspension, the active ingredient crystallizing out of the suspension, and removing the active ingredient in the form of product particles and finally drying the product particles. The primary particles and the product particles have a crystalline nature, are present in the most stable crystal modification of the active ingredient, have a crystal surface of 3 – 10 m2/g and the size distribution of the primary particles and product particles is d50 = 1 — 2 μm, d99 < 6 μm and d100 < 12 μm each. The invention further relates to active ingredient microparticles which can be obtained by said method and to a molded article product containing the active ingredient particles.