Asenapine Microspheres for 30-Day Sustained Release
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Solution Overview
Problem
There is a need for an extended-release asenapine-encapsulating microsphere formulation with a high drug load (>15% by weight), small particle size (15-40 μm), and long release duration (approximately 30 days) to effectively treat schizophrenia and acute mania associated with bipolar disorder.
Innovation Solution
The development of microsphere formulations comprising asenapine encapsulated in biodegradable polymer microspheres, specifically polylactide (PLA) microspheres, which have a drug load of at least 15% by weight and an average particle size of 15-40 μm, allowing for a controlled release of asenapine over a period of 30 days.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If asenapine is encapsulated in biodegradable polymer microspheres for extended release, then the release duration is extended to 30 days, but achieving high drug load (>15% by weight) while maintaining small particle size (15-40 μm) becomes difficult
Solution Approach 1:
The patent modifies critical parameters including polymer molecular weight (10-100 kDa range), drug-to-polymer ratio (1:4 to 1:1), solvent composition (dichloromethane/benzyl alcohol ratios), and homogenization conditions (speed and time) to achieve the target particle size range of 15-40 μm while maintaining drug load >15% and sustained release duration of 30 days
Solution Approach 2:
The invention uses composite polymer materials, specifically blending polylactide (PLA) with other biodegradable polymers such as polyglycolide (PGA) or polylactide-co-glycolide (PLGA) in specific ratios, to optimize both the mechanical properties for small particle formation and the degradation rate for 30-day sustained release
2Quantity of substance
If the drug load is increased to >15% by weight, then the therapeutic effectiveness is improved, but the particle size tends to increase beyond the desired 15-40 μm range
Solution Approach 1:
The patent optimizes the drug-to-polymer ratio parameter within the range of 1:4 to 1:1, and controls the solvent evaporation rate and homogenization intensity to achieve high drug load (>15% by weight) while maintaining small particle size (15-40 μm) through precise parameter control during microsphere formation
Solution Approach 2:
The microsphere formulation incorporates a porous polymer matrix structure with controlled porosity (30-70% void volume), allowing high drug loading capacity within the particle while maintaining small external particle size through internal pore space utilization for drug accommodation
3Length of moving object
If the particle size is reduced to 15-40 μm for better tissue distribution, then the injection capability is improved, but the drug load percentage becomes difficult to maintain above 15% by weight
Solution Approach 1:
The patent creates a porous internal structure within the 15-40 μm microspheres with controlled pore size (1-10 μm) and porosity (30-70%), enabling high drug loading capacity by utilizing the internal void space, thus achieving both small particle size for injectability and high drug load >15% by weight
Solution Approach 2:
The formulation employs a core-shell microsphere structure where asenapine is encapsulated within the polymer matrix core, allowing maximum drug concentration within the small 15-40 μm particle volume while maintaining structural integrity and controlled release properties
4Productivity
If a high drug load of >15% by weight is achieved, then the dosing frequency can be reduced to once every 30 days, but the formulation complexity increases
Solution Approach 1:
The patent uses composite biodegradable polymers (PLA, PGA, PLGA) with specific molecular weights and degradation rates that naturally provide sustained release over 30 days at high drug load (>15%), simplifying the formulation by relying on the inherent properties of the polymer composite rather than complex release mechanisms
Solution Approach 2:
The biodegradable polymer matrix automatically degrades in the body over 30 days, providing self-regulated drug release without requiring external control mechanisms, thereby achieving once-monthly dosing frequency while maintaining relatively simple formulation composition
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 microsphere formulation achieves a sustained release of asenapine for 30 days, providing effective treatment for schizophrenia and acute mania associated with bipolar disorder with improved patient compliance due to reduced dosing frequency.
Implementation Method 1
a biodegradable polymer comprising a polylactide polymer (a 'PLA')
Implementation Method 2
combining the dispersed phase with the continuous phase in a homogenizer
Data Source
AI summary
Microsphere formulations comprising asenapine are provided. Methods for making and using the microsphere formulations are also provided.