Flupirtine Controlled Release Formulation for Stable Plasma Levels

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Solution Overview

Problem

Current pharmaceutical formulations of flupirtine for chronic pain management require frequent administration due to rapid release and absorption, leading to plasma concentration fluctuations, poor patient compliance, and increased side effects, with existing sustained-release formulations offering limited retarding effect and gastric juice solubility issues.

Innovation Solution

Development of solid pharmaceutical preparations with flupirtine or its physiologically tolerable salts in the form of active substance compacts coated with a sustained-release component, achieving a uniform and controlled release over 4 hours to 24 hours, using a process that optimizes particle size and coating for reproducible dosing and reduced side effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If flupirtine is administered in conventional formulations, then rapid analgesic effect is achieved, but frequent administration is required leading to plasma concentration fluctuations and poor patient compliance

Engineering Contradiction:
Improveonset of analgesic effectVSAvoidduration of analgesic effect
Core Design Contradiction:
SpeedVSDuration of action of moving object

Solution Approach 1:

The formulation is segmented into two distinct components: immediate-release granules containing flupirtine maleate and sustained-release granules containing flupirtine maleate coated with a polymer matrix. This segmentation allows the immediate-release component to provide rapid onset of action while the sustained-release component maintains therapeutic levels over an extended period, eliminating the need for frequent dosing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges immediate-release and sustained-release mechanisms into a single combined formulation. The capsule contains both types of granules in specific ratios (immediate-release: 20-40% of total flupirtine maleate, sustained-release: 60-80%), allowing the drug to exhibit both rapid onset and prolonged duration of action simultaneously

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If flupirtine is administered three times daily, then sufficient plasma concentration is maintained, but patient compliance deteriorates and administration errors increase

Engineering Contradiction:
Improveplasma concentration stabilityVSAvoidadministration frequency
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sustained-release granules provide continuous release of flupirtine maleate over 12-24 hours through a polymer matrix that controls diffusion. This continuous release mechanism maintains stable plasma concentrations throughout the dosing interval, allowing once-daily or twice-daily administration while ensuring reliable therapeutic effect without peaks and troughs

Inventive Principle:
Principle #20Continuity of useful action

3Stability of the object's composition

If shellac/Eudragit L100 is used as sustained-release component, then gastric juice resistance is achieved, but retarding effect is insufficient with 43% release in first hour

Engineering Contradiction:
Improvegastric juice resistanceVSAvoidactive ingredient release rate
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent changes the polymer matrix composition from shellac/Eudragit L100 to a specific copolymer (ethyl acrylate-methyl methacrylate copolymer, ratio 3:7) with controlled porosity and permeability parameters. This polymer provides optimal balance between gastric resistance and controlled release, achieving less than 10% release in the first hour while maintaining stability in acidic conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sustained-release granules use a composite structure combining flupirtine maleate with a polymer matrix (ethyl acrylate-methyl methacrylate copolymer) and pore-forming agents (such as calcium carbonate or silicon dioxide). This composite material provides both gastric juice resistance and controlled release kinetics, overcoming the limitations of shellac/Eudragit formulations

Inventive Principle:
Principle #40Composite materials

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 controlled release formulation allows for once or twice daily administration, maintaining therapeutic plasma levels, reducing side effects, and preventing 'dose dumping, while ensuring uniform and prolonged analgesic action without significant pH dependence.

Implementation Method 1

The release of the active ingredient is controlled by the matrix and pH

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The active ingredient release is controlled by swelling of the matrix former. The release of the active ingredient is therefore matrix-controlled, i.e. the release takes place over the entire tablet (single unit dosage form) through the degradation of the matrix taking place over time.

Methodology Applied
Scientific EffectMatrix-controlled release:

Data Source

PatentEP1795186B2Flupirtin comprising medicament formulation with a controlled release of the active agent
Publication Date: 2017.12.06 TEVA
  • EP1795186B2 patent drawingFigure 1A~1B
  • EP1795186B2 patent drawingFigure 1C~1D
  • EP1795186B2 patent drawingFigure 2A~2B

AI summary

A solid pharmaceutical preparation is provided, comprising flupirtine or its physiologically acceptable salts as the active ingredient, wherein at least a portion of the flupirtine or its physiologically acceptable salts is present as a delayed-release formulation, wherein a. the delayed-release formulation comprises active ingredient compacts coated with a sustained-release component, preferably uniformly, and optionally comprising pharmaceutically customary excipients, such that uniform release of the flupirtine from the compacts is ensured, and b. the active ingredient compacts have a particle size of 160 to 800 µm, preferably 250 to 500 µm, and are preferably spherical or approximately spherical, as well as active ingredient compacts and a method for their preparation.