Thixotropic Protein Gel Stabilization via Cyclodextrin and PEG

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Solution Overview

Problem

High-concentration protein preparations are prone to aggregation and instability due to physical and chemical stresses, such as pH variations, temperature changes, and agitation, leading to reduced efficacy and potential immunoreactions, with existing stabilization methods being limited in effectiveness and convenience.

Innovation Solution

A thixotropic gel preparation containing a protein and a combination of cyclodextrin or its derivatives and polyethylene glycol, which forms a stable hydrogel structure that protects proteins from aggregation and denaturation by reducing protein-protein interactions and exposure to gas-liquid interfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If protein concentration is increased to reduce administration dose and improve convenience, then productivity and patient convenience are improved, but aggregation and instability occur more frequently

Engineering Contradiction:
Improveprotein concentrationVSAvoidaggregation resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces cyclodextrin and polyethylene glycol as intermediary substances that mediate between protein molecules. Cyclodextrin forms inclusion complexes with hydrophobic regions of proteins, while polyethylene glycol creates a steric barrier, preventing direct protein-protein interactions that lead to aggregation. This intermediary approach allows high protein concentration without compromising stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite stabilization system combining cyclodextrin (a cyclic oligosaccharide with cavity structure) and polyethylene glycol (a linear polymer). This composite approach leverages the cavity-inclusion mechanism of cyclodextrin and the steric exclusion effect of polyethylene glycol to provide comprehensive protection against aggregation, achieving superior stability compared to single additives.

Inventive Principle:
Principle #40Composite materials

2Reliability

If stabilizers are added to prevent aggregation, then protein stability is improved, but the number of additives and formulation complexity increase

Engineering Contradiction:
Improveprotein stabilityVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent demonstrates that the cyclodextrin-polyethylene glycol combination provides multiple functions simultaneously: preventing aggregation through steric barrier and inclusion complex formation, protecting against denaturation, and maintaining solubility. This multi-functional approach reduces the need for multiple separate stabilizers, simplifying the overall formulation despite the high protein concentration requirement.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If freeze-drying is used to stabilize protein, then long-term stability is improved, but reconstitution is required which may cause denaturation and reduces patient convenience

Engineering Contradiction:
Improvelong-term stabilityVSAvoidpatient convenience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary stabilization action by incorporating cyclodextrin and polyethylene glycol into the protein formulation before storage. This pre-protection mechanism allows the protein to maintain stability in liquid form without requiring freeze-drying or other complex preservation methods, enabling direct subcutaneous injection and eliminating the reconstitution step that patients would otherwise need to perform.

Inventive Principle:
Principle #10Preliminary action

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 gel preparation effectively stabilizes proteins against physical and chemical stresses, maintaining a high concentration of active protein and preventing aggregation, thereby enhancing the stability and shelf-life of protein preparations for long-term use.

Implementation Method 1

A thixotropic gel preparation containing a protein and a combination of cyclodextrin or its derivatives and polyethylene glycol, which forms a stable hydrogel structure that protects proteins from aggregation and denaturation

Methodology Applied
Scientific EffectGel formation: Gel

Implementation Method 2

protects proteins from aggregation and denaturation by reducing protein-protein interactions and exposure to gas-liquid interfaces

Methodology Applied
Scientific EffectSteric hindrance:

Implementation Method 3

A thixotropic gel preparation containing a protein and a combination of cyclodextrin or its derivatives and polyethylene glycol

Methodology Applied
Scientific EffectThixotropy: Thixotropy

Data Source

PatentEP2949336B1Stabilized protein gel preparation
Publication Date: 2018.09.05 TERUMO KK
  • EP2949336B1 patent drawingFigure 1A
  • EP2949336B1 patent drawingFigure 1B~2A
  • EP2949336B1 patent drawingFigure 2B~3A

AI summary

[Object] To provide a protein preparation which enables reduction of aggregation and a stable long-time preservation, in a protein preparation having a high concentration or a protein preparation susceptible to aggregation. [Solution] The protein preparation is a gel preparation which is thixotropic and in which an included protein is protected from a physical or chemical stress, is inhibited from aggregation, and is thereby let exist stably.