Peptide Microparticles via Ionic Complex for Sustained Release

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Solution Overview

Problem

Conventional methods for preparing peptide-containing microspheres face challenges such as initial burst of drugs, incomplete release, and low encapsulation efficiency, which hinder sustained and controlled release of peptide drugs, requiring a method that avoids organic solvents and ensures uniform particle size for effective drug delivery.

Innovation Solution

A method involving the formation of an ionic complex of physiologically active peptides with a water-soluble polymer, followed by mixing with a biodegradable, water-insoluble polymer in a non-aqueous solvent, and subsequent removal of the solvent to create microparticles that exhibit sustained release and high encapsulation efficiency without excessive organic solvent use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If peptide drugs are encapsulated in microspheres comprising an aliphatic polyester, then sustained release can be achieved, but initial burst effect occurs and drug release rate cannot be maintained constantly

Engineering Contradiction:
Improvedrug release periodVSAvoiddrug release rate control
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the polymer carrier by using carboxyl-terminal modified polypeptides with specific molecular weights (1,000-5,000 Daltons) and controlling the carboxyl group content (0.1-10 mmol/g). These parameter changes enable sustained release without initial burst effect by optimizing the polymer-drug interaction and degradation rate.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite system combining carboxyl-terminal modified polypeptides with peptide drugs, where the modified polypeptide serves as both the carrier matrix and the release control mechanism. This composite approach allows the material to provide both structural integrity for sustained release and controlled release properties.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional phase separation method is used to prepare microparticles, then microparticles can be formed, but complicated organic solvents must be removed

Engineering Contradiction:
Improvemicroparticle formationVSAvoidsolvent removal process
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for complicated organic solvent removal processes by using a water-soluble carboxyl-terminal modified polypeptide as the carrier. The microparticles are formed in aqueous medium, and the carrier itself provides the necessary structural properties without requiring additional organic solvents for particle formation and stabilization.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The carboxyl-terminal modified polypeptide acts as an intermediary that enables microparticle formation in aqueous medium without requiring organic solvents. The modified polypeptide with its specific molecular weight and carboxyl group content serves as a mediator between the peptide drug and the aqueous environment, facilitating self-assembly into microparticles.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If peptide drugs are administered by injection, then bioavailability is improved, but frequent administration is required due to short half-life

Engineering Contradiction:
ImprovebioavailabilityVSAvoidadministration frequency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-modifying the peptide drug with carboxyl-terminal modification before encapsulation. This preliminary chemical modification enables the peptide to be stably encapsulated in the microparticle matrix, which then provides sustained release over extended periods, eliminating the need for frequent re-administration while maintaining high bioavailability.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If peptide drugs are encapsulated with high encapsulation ratio, then drug loading is improved, but initial burst effect increases due to surface adsorption

Engineering Contradiction:
Improveencapsulation ratioVSAvoiddrug release control
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the surface chemistry parameters of the microparticle carrier by using carboxyl-terminal modified polypeptides with controlled molecular weights and carboxyl group densities. These parameter changes reduce non-specific surface adsorption of peptide drugs, thereby minimizing initial burst effect while maintaining high encapsulation efficiency through optimized polymer-drug interactions in the bulk matrix.

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

The method achieves high encapsulation efficiency, prevents initial burst, and ensures continuous drug release for a predetermined period, with uniform particle size and reduced toxicity from organic solvents, enhancing the therapeutic efficacy of peptide drugs.

Implementation Method 1

forming an ionic complex of the physiologically active peptide and water-soluble polymer

Methodology Applied
Scientific EffectIonic complex formation: Ion Repulsion/Attraction

Data Source

PatentEP2654725B1Method for preparing microparticles containing physiologically active peptide
Publication Date: 2020.11.25 SAMYANG BIOPHARMLS CORP
  • EP2654725B1 patent drawingFigure 1~3
  • EP2654725B1 patent drawingFigure 4
  • EP2654725B1 patent drawing

AI summary

Disclosed are microparticles containing physiologically active peptides, a method for preparing the same, and a pharmaceutical composition comprising the same.