Biodegradable Microparticles for Botulinum Toxin Delivery
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Solution Overview
Problem
Current methods for formulating biodegradable polymer microparticles for extended release of protein drugs, such as botulinum toxin, face challenges in maintaining protein bioactivity and achieving uniform dispersion, leading to heterogeneous particle sizes and reduced efficacy.
Innovation Solution
A method involving the steps of mixing dehydrated protein in an aqueous solution, precipitating the protein, washing the precipitant with a solvent, dispersing the solvent-washed precipitant in a polymer solution, and preparing polymer microparticles by emulsification, which enhances uniform encapsulation and controlled release of botulinum toxin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid protein powders are incorporated to make emulsions, then protein bioactivity is maintained, but uniform dispersion is difficult and manufacturing complexity increases
Solution Approach 1:
The patent changes the physical state of the protein from solid powder to aqueous solution, and changes the emulsion type from water-in-oil to oil-in-water. This parameter change enables uniform dispersion of protein while maintaining bioactivity, resolving the contradiction between reliability and manufacturing complexity
Solution Approach 2:
The patent uses an aqueous buffer solution as an intermediary medium to dissolve the protein before emulsification. This intermediary step facilitates uniform distribution of protein throughout the polymer matrix, avoiding the difficulties of directly incorporating solid protein powders
2Manufacturing precision
If water-dissolved proteins are used, then uniform dispersion is achieved, but protein denaturation occurs at water/solvent interface
Solution Approach 1:
The patent inverts the traditional water-in-oil emulsion approach to an oil-in-water emulsion. This inversion places the organic polymer solution as the dispersed phase in an aqueous continuous phase, eliminating the water/solvent interface that causes protein denaturation while maintaining uniform dispersion
Solution Approach 2:
The patent creates a protein-friendly aqueous environment as the continuous phase, protecting the dissolved protein from exposure to denaturing organic solvent interfaces. The protein remains in the aqueous phase throughout the emulsion process, maintaining its bioactivity
3Duration of action of moving object
If microparticle formulations are used, then extended release is achieved, but particle size is heterogeneous and requires large-diameter needles
Solution Approach 1:
The patent employs dynamic homogenization processes during emulsion formation to control particle size distribution. By applying mechanical energy through stirring and homogenization, the system produces microparticles with narrow size distribution, enabling both extended release and compatibility with smaller gauge needles
Solution Approach 2:
The patent optimizes emulsion parameters including droplet size, polymer concentration, and homogenization conditions to produce microparticles with controlled and uniform size. This enables extended release functionality while achieving particle sizes suitable for smaller gauge needle injection
4Ease of manufacture
If in situ gel forming method is used, then simplified manufacturing is achieved, but only small molecular drugs and peptides can be delivered
Solution Approach 1:
The patent modifies the in situ gel forming approach to accommodate protein drugs by using oil-in-water emulsions where the protein remains in the aqueous phase. This universal formulation strategy enables the method to deliver both small molecular drugs/peptides and protein drugs, expanding adaptability while maintaining 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
The method maintains the biological activity of botulinum toxin and achieves controlled release, extending the duration of efficacy and improving pharmacokinetics, allowing for safer and more effective administration.
Implementation Method 1
precipitating the protein from the solution to form a precipitant
Implementation Method 2
preparing polymer microparticles by emulsification
Data Source
AI summary
Methods for the formulation of biodegradable microparticles for delivery of protein drugs, such as botulinum toxin, have been developed. The methods include the steps of precipitating and washing proteins with organic solvent to remove water prior to dispersing in polymer-dissolved organic solvent to prevent exposure to water/solvent interfaces and maintain bioactivity of the protein drugs and fabrication of microparticles by either template or emulsion method. Biodegradable microparticles, formed of one or more biodegradable polymers having entrapped in the polymer one or more protein agents, such as botulinum toxin, are also provided. Precipitated botulinum toxin and botulinum toxin-loaded microparticles can also be formulated into thermogels or crosslinked hydrogels. The stability of the protein within these microparticles, as well as the controlled release of the entrapped agents, provides for sustained efficacy of the agents.