PLGA Celecoxib Microspheres for Sustained Intra-Articular Release
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Solution Overview
Problem
Existing NSAIDs, including celecoxib, cause significant side effects such as cardiovascular and gastrointestinal issues, and existing formulations for localized delivery of celecoxib suffer from rapid drug clearance and inflammation due to macrophage phagocytosis, limiting their effectiveness in treating joint disorders.
Innovation Solution
Development of biodegradable PLGA microspheres with specific lactic acid to glycolic acid ratios (75:25) and inherent viscosity of 0.5-1.0 dl/g, non-covalently carrying celecoxib, which provide sustained release over a period of one month to six months, minimizing systemic exposure and side effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If PLGA microspheres with mean diameters between 10-20 μm are used for celecoxib delivery, then the microspheres can be injected into joint tissue, but a significant portion is subject to macrophage phagocytosis and removal, causing inflammation and reducing formulation suitability
Solution Approach 1:
The patent changes the particle size parameter from the conventional 10-20 μm range to a larger 20-100 μm range. This parameter modification reduces phagocytosis by macrophages while maintaining injectability, thereby resolving the contradiction between ease of injection and reduction of harmful inflammatory responses.
2Productivity
If PLGA microspheres with mean diameters under 10 μm are used, then the microspheres can be effectively delivered to the joint site, but they are subject to phagocytosis and removal by macrophages leading to inflammation
Solution Approach 1:
The patent modifies the particle size parameter from under 10 μm to 20-100 μm. This change maintains effective joint site delivery while avoiding macrophage phagocytosis, thus resolving the contradiction between delivery efficiency and harmful inflammatory effects.
3Object-affected harmful factors
If existing NSAIDs are used to treat joint diseases, then pain and inflammation are reduced, but severe side effects occur due to COX-1 and COX-2 inhibition including cardiovascular and gastrointestinal issues
Solution Approach 1:
The patent applies local quality by delivering celecoxib locally into the joint space through injectable microspheres, rather than systemically via oral administration. This localized delivery concentrates the drug at the site of action (joint), providing effective pain and inflammation relief while minimizing systemic exposure and associated cardiovascular and gastrointestinal side effects.
Solution Approach 2:
The patent uses biodegradable PLGA microspheres as an intermediary carrier system. This intermediary enables controlled local delivery of celecoxib to the joint, acting as a mediator that releases the drug slowly over time, thereby achieving therapeutic effects while reducing systemic harmful effects.
4Duration of action of moving object
If PLGA microspheres are used for sustained celecoxib release, then drug release duration is extended, but formulations may stop releasing drug after an initial burst phase
Solution Approach 1:
The patent optimizes the PLGA molecular weight parameter (inherent viscosity 0.3-1.5 dl/g) and composition ratio (75:25 lactic acid to glycolic acid) to ensure sustained and reliable drug release. These parameter changes prevent the common issue of burst release followed by premature cessation, maintaining consistent release over the extended duration.
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 microspheres achieve continuous celecoxib release for extended periods, reducing systemic side effects and providing effective treatment for joint disorders like osteoarthritis with improved therapeutic efficacy.
Implementation Method 1
biodegradable PLGA microspheres... releases celecoxib for at least one month... when present in a suitable joint-related tissue
Implementation Method 2
PLGA microspheres... releases celecoxib for at least one month... continuous celecoxib release
Data Source
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AI summary
This invention provides a biodegradable microsphere, wherein the microsphere (i) has a diameter of from 1 ?m to 500 ?m; (ii) comprises a polylactic-co-glycolic acid copolymer (PLGA) matrix; (iii) carries pharmaceutical celecoxib; and (iv) when present in a suitable joint-related tissue, releases celecoxib for at least one month. This invention also provides related injectable formulations, methods for treating joint-related disorders, and kits.