PLGA Microparticles for Sustained Peptide Release
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Solution Overview
Problem
Existing pharmaceutical compositions fail to provide a continuous and efficient slow release of water insoluble peptide salts, such as LHRH agonists, for a duration exceeding six months.
Innovation Solution
A pharmaceutical composition comprising microparticles made of a copolymer of lactic and glycolic acid (PLGA) with specific size distributions and inherent viscosities, incorporating a water insoluble peptide salt, which allows for a sustained release over six months.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If existing pharmaceutical compositions are used, then immediate release of the peptide is achieved, but continuous and efficient slow release for more than six months cannot be provided
Solution Approach 1:
The invention divides the peptide drug into microparticle form, segmenting the active substance into discrete carriers that can be controlled for sustained release. The microparticles are formed by mixing the peptide with PLGA polymer and processing through extrusion and milling, creating numerous small particles with controlled size distribution (D(v,0.1)=10-30 μm, D(v,0.5)=30-70 μm, D(v,0.9)=50-110 μm) that provide prolonged release kinetics.
Solution Approach 2:
The invention employs specific parameter optimization including PLGA inherent viscosity (0.1-0.9 dl/g), microparticle size distribution, and polymer composition (lactide/glycolide ratio) to control the release profile. By adjusting these parameters, the formulation achieves both immediate and sustained release phases, with the slow release phase continuing efficiently for more than six months.
2Duration of action of moving object
If microparticles with specific size distribution and PLGA properties are used, then continuous slow release for more than six months is achieved, but formulation complexity increases
Solution Approach 1:
The invention establishes specific parameter ranges for PLGA inherent viscosity (0.1-0.9 dl/g), microparticle size distribution (D(v,0.1)=10-30 μm, D(v,0.5)=30-70 μm, D(v,0.9)=50-110 μm), and polymer composition to achieve the desired release profile. These parameter specifications provide a systematic approach to formulation development while ensuring reproducible sustained release performance for more than six months.
Solution Approach 2:
The invention uses composite material formulation combining PLGA polymer with water-insoluble peptide salts. The composite microparticles leverage the biodegradable properties of PLGA and the therapeutic properties of the peptide, creating a material system that provides controlled release without requiring complex delivery mechanisms or additional components.
3Duration of action of moving object
If PLGA with high inherent viscosity is used, then sustained release is improved, but manufacturing difficulty increases
Solution Approach 1:
The invention specifies PLGA inherent viscosity within the range of 0.1-0.9 dl/g, balancing the competing requirements for sustained release performance and manufacturability. This parameter optimization allows the formulation to achieve prolonged release while remaining compatible with standard manufacturing processes including extrusion and milling operations.
Solution Approach 2:
The invention uses PLGA inherent viscosity values that are sufficient to achieve the required sustained release duration without being excessively high. By selecting viscosity values in the moderate range (0.1-0.9 dl/g) rather than maximizing viscosity, the formulation achieves adequate release control while maintaining ease of processing and manufacturing feasibility.
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 composition achieves an immediate release of the peptide within hours followed by a constant and significant release over at least 168 days, enhancing treatment efficacy and patient compliance.
Implementation Method 1
a copolymer of lactic and glycolic acid (PLGA) incorporating, as active substance, a water insoluble peptide salt
Implementation Method 2
water insoluble peptide salt
Implementation Method 3
said microparticles furthermore having a size distribution defined as follows: D (v,0.1) is between 10 and 30 micrometers, D (v,0.5) is between 30 and 70 micrometers, D (v,0.9) is between 50 and 110 micrometers
Implementation Method 4
a copolymer of lactic and glycolic acid (PLGA)
Data Source
AI summary
Pharmaceutical composition made of microparticles for the slow release of an active substance at least during a period covering the 6th month after injection of said composition, said composition comprising a group of microparticles made of a copolymer of the PLGA type which incorporate an active substance in the form of a water insoluble peptide salt; said copolymer furthermore comprising at least 75% of lactic acid and an inherent viscosity between 0.1 and 0.9 dl/g, as measured in chloroform at 25° C. and at a polymer concentration of 0.5 g/dL; said microparticles furthermore having a size distribution defined as follows: D (v,0.1) is between 10 and 30 micrometers, D (v,0.5) is between 30 and 70 micrometers, D (v,0.9) is between 50 and 1 10 micrometers.