Drug-Loaded Polymer Microbeads for Sustained Embolization Therapy
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Solution Overview
Problem
Current embolic agents for embolization therapy lack efficient preloading of drugs and have suboptimal pharmacokinetic release profiles, requiring advance preparation and ceasing drug delivery within a few days post-implantation.
Innovation Solution
Development of drug-loaded microbead compositions using water-swellable polymer microbeads that pre-load therapeutic agents, allowing for sustained drug release over extended periods, typically up to 30 days, by embedding the agent within a polymer matrix without direct chemical bonding, and drying to low water content for stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If embolic agents are provided without preloaded drug, then the embolic agents can be stored and transported easily, but the physician must order pharmacy to load drug into embolic agent well in advance of surgery (at least 24 hours before)
Solution Approach 1:
The patent applies preliminary action by pre-loading the therapeutic agent into the embolic agent during manufacturing, so that the drug-loaded embolic agent is ready for immediate use at the time of surgery without requiring advance pharmacy preparation. This eliminates the 24-hour advance loading requirement while maintaining ease of manufacture through integrated drug-embolic agent production processes.
2Reliability
If embolic agents are used clinically, then embolization therapy can be performed, but the embolic agents have suboptimal pharmacokinetic release profile that stops releasing drug into target treatment site after only a few days (typically within about 3 days) after implantation
Solution Approach 1:
The patent applies parameter changes by modifying the physical and chemical parameters of the embolic agent matrix (such as polymer composition, porosity, degradation rate, and drug-polymer interaction) to control and extend the drug release profile. These parameter adjustments enable sustained release over periods exceeding 3 days, thereby improving both reliability and duration of action simultaneously.
3Duration of action of moving object
If drug is loaded into embolic agent in advance, then sustained drug release can be achieved, but the embolic agent requires complex pre-surgery preparation process
Solution Approach 1:
The patent applies merging by combining the drug loading process with the embolic agent manufacturing process into a single integrated operation. The therapeutic agent is incorporated into the embolic agent matrix during production, eliminating separate loading steps and reducing overall process complexity while achieving sustained drug release.
4Stability of the object's composition
If water content in drug-loaded microbeads is reduced to less than 1% by weight, then stability is improved, but additional drying steps are required in the preparation process
Solution Approach 1:
The patent applies phase transitions by utilizing freeze-drying (lyophilization) to remove water from the drug-loaded microbeads. The process involves freezing the aqueous formulation and then sublimating the ice under vacuum, efficiently reducing water content to less than 1% by weight while improving stability. This phase transition approach is integrated into the manufacturing process to minimize additional complexity.
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 microbead compositions provide continuous drug release at the treatment site for at least 7 days, enhancing therapeutic efficacy and reducing preparation time by eliminating pre-surgery drug loading, while maintaining stability and avoiding microcatheter clogging.
Implementation Method 1
a water-swellable polymer material, such as a polymer material capable of forming a hydrogel
Implementation Method 2
combining the initial mixture with a first solvent composition in which the therapeutic agent is less soluble than in the aqueous solvent to form a second mixture, and stirring the second mixture rapidly to form particles of the complex in the second mixture
Implementation Method 3
stirring the synthesis mixture rapidly to form drug-loaded microbeads in the synthesis mixture
Implementation Method 4
removing water from the drug-loaded microbeads to form a drug-loaded microbead composition having a water content of less than 1% by weight
Data Source
AI summary
Methods for preparing a drug-loaded microbead compositions and embolization compositions include loading a therapeutic agent into a water-swellable polymer material to form microbeads, then removing water from the microbeads. The drug-loaded microbead compositions include microbeads of a water-swellable polymer material and a complex of a carrier and a therapeutic agent chemically bonded to the carrier. The complex is embedded in the polymer material. The therapeutic agent is not chemically bonded to the water-swellable polymer material. The drug-loaded microbead composition has a water content of less than 1% by weight, based on the total weight of the drug-loaded microbead composition. The drug-loaded microbead composition may be rehydrated to form an embolization composition for use in in embolization therapy.