Polymeric Microspheres via Supercritical Fluid Processing
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Solution Overview
Problem
Conventional methods for producing polymeric microspheres for controlled drug delivery are inefficient, costly, and result in non-uniform particle sizes, with exposure to organic solvents potentially damaging therapeutic agents and compromising sterility.
Innovation Solution
The use of supercritical fluids, such as carbon dioxide, with or without cosolvents, to form uniform polymeric spheres that encapsulate therapeutic agents, reducing processing time and costs while maintaining the integrity of the encapsulated proteins and eliminating the need for toxic organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods using organic solvents are used to produce polymeric microspheres, then the microspheres can be formed, but the therapeutic agents may be damaged and sterility is compromised
Solution Approach 1:
The patent changes the physical state and chemical composition of the fluid system by using supercritical carbon dioxide instead of conventional organic solvents. This parameter change eliminates toxic solvent exposure while maintaining effective microsphere formation, thereby protecting therapeutic agent integrity and ensuring sterility.
Solution Approach 2:
The patent replaces the chemical mechanism of organic solvent-based microsphere formation with a physical mechanism using supercritical fluid expansion. This substitution eliminates harmful chemical interactions with therapeutic agents while achieving the same microsphere formation objective through controlled depressurization and phase change.
2Ease of manufacture
If conventional multi-step processing methods are used, then polymeric microspheres can be produced, but the processing time is excessive and costs are high
Solution Approach 1:
The patent merges multiple conventional processing steps (microsphere formation, solvent removal, and sterilization) into a single integrated supercritical fluid process. The supercritical carbon dioxide simultaneously acts as the formation medium and the sterilizing agent, eliminating sequential steps and dramatically reducing processing time while maintaining production capability.
Solution Approach 2:
The patent implements a continuous single-step process where supercritical carbon dioxide is maintained throughout the microsphere formation and sterilization operations. This continuous action eliminates the interruptions and transfer operations required in conventional multi-step methods, reducing processing time while preserving ease of manufacture.
3Ease of manufacture
If conventional methods are used to produce polymeric microspheres, then the microspheres can be formed, but the particle size distribution is wide and non-uniform
Solution Approach 1:
The patent utilizes the unique parameter characteristics of supercritical fluids, particularly the ability to precisely control density and solubility through pressure and temperature adjustments. This parameter control enables uniform nucleation and growth conditions during microsphere formation, resulting in narrow particle size distribution while maintaining ease of manufacture.
Solution Approach 2:
The patent replaces the mechanical mixing and emulsification processes of conventional methods with a controlled phase separation mechanism in the supercritical fluid system. This substitution provides more uniform mass and heat transfer, leading to consistent microsphere formation with improved particle size uniformity while preserving manufacturing simplicity.
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
This method enables the production of uniform polymeric spheres with improved encapsulation efficiency, reduced processing time, and enhanced sterility, effectively addressing the inefficiencies and sterility concerns of traditional methods.
Implementation Method 1
The use of supercritical fluids, such as carbon dioxide, with or without cosolvents, to form uniform polymeric spheres
Implementation Method 2
particles are formed as a result of rapid expansion of the supercritical fluid. This process is known as rapid expansion of supercritical solution (RESS)
Implementation Method 3
PLA is solubilized in the organic solvent and sprayed into the supercritical fluid continuous phase. Here supercritical fluid is used as an anti-solvent that causes particle precipitation from the liquid. This method is known as gas anti-solvent precipitation (GAS)
Data Source
AI summary
This invention is an improved process to formulate polymeric microspheres/nanospheres and encapsulate therapeutic proteins or other useful substances, and a polymer sphere apparatus. The invention is also methods of purifying protein-containing-polymeric-microspheres from unused polymer, and an apparatus therefore.