Two-Stage Microchip Drug Release for Stable Therapeutic Levels
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Solution Overview
Problem
Existing drug delivery devices struggle to maintain drug plasma levels within a selected therapeutic range for extended periods and often experience undesirable lag times in reaching effective levels due to bolus or continuous-release mechanisms.
Innovation Solution
A microchip-based drug delivery device with a two-stage release system, utilizing electrothermal ablation to open reservoir caps and a drug-permeable membrane, where drug is initially released into a depot space and then diffuses into the patient, allowing for controlled release over time without relying on bioerodible matrices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If bolus delivery is used, then initial drug concentration is high, but drug levels rapidly decrease below therapeutic range
Solution Approach 1:
The device segments the drug delivery process into two distinct stages: a first stage with high release rate to achieve rapid therapeutic effect, and a second stage with lower release rate to maintain therapeutic levels. This is accomplished through a dual-channel release mechanism where drug can be delivered through both a membrane and a reservoir opening simultaneously, allowing the system to provide both rapid initial dosing and sustained maintenance dosing
Solution Approach 2:
The device employs periodic action by providing pulsatile release of drug in discrete doses over extended periods. The microchip reservoir array delivers drug in controlled pulses, with each reservoir releasing drug on a predetermined schedule, creating a periodic delivery pattern that maintains therapeutic levels while avoiding continuous exposure
2Duration of action of moving object
If extended-release device is used, then drug levels remain in therapeutic range longer, but lag time to reach effective levels is increased
Solution Approach 1:
The device segments the drug delivery process into two distinct stages: a first stage with high release rate to achieve rapid therapeutic effect, and a second stage with lower release rate to maintain therapeutic levels. This is accomplished through a dual-channel release mechanism where drug can be delivered through both a membrane and a reservoir opening simultaneously, allowing the system to provide both rapid initial dosing and sustained maintenance dosing
Solution Approach 2:
The device performs preliminary action by providing an initial high-rate drug release phase that rapidly achieves therapeutic levels before transitioning to sustained release. The first stage of drug release is designed to quickly establish effective plasma concentrations, eliminating the lag time problem of conventional extended-release devices
3Duration of action of moving object
If passive diffusion from matrix material is used, then extended release is achieved, but device complexity increases
Solution Approach 1:
The device extracts the need for bioerodible matrix materials by using a different mechanism entirely. Instead of relying on matrix degradation to control release, the invention uses electrically controlled reservoir caps that can be opened on demand, combined with a drug-permeable membrane for controlled diffusion. This simplifies the release mechanism by removing the complex matrix degradation process
Solution Approach 2:
The device replaces the passive mechanical diffusion process with an electrically controlled system. Reservoir caps can be opened using electrothermal ablation or other electrical mechanisms, and drug release through the membrane can be controlled by electrical signals. This substitution of electrical control for passive mechanical diffusion provides more precise and programmable release patterns
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 device maintains systemic drug concentrations within a therapeutic window for longer periods, providing nearly linear drug release and reducing lag times by combining discrete and continuous dosing, independent of bioerodible materials.
Implementation Method 1
one or more corresponding reservoir caps configured to be electrically activated to unclose the one or more drug release apertures
Implementation Method 2
release the drug by diffusion through the drug-permeable membrane and into the aqueous environment
Data Source
AI summary
Drug delivery devices and methods of controlled drug delivery to a patient are provided. The drug delivery device may include one or two microchip elements, each of which has a body portion with one or more drug release apertures in fluid communication with at least one containment reservoir. The drug release apertures are closed off by one or more reservoir caps which can be electrically activated to open the drug release apertures. The drug delivery device also includes (i) a drug formulation disposed in the at least one containment reservoir, and (ii) at least one drug-permeable membrane. In some cases, an outer housing is spaced a distance from an exterior wall of the body portion of the microchip element, the outer housing includes the at least one drug-permeable membrane, and a depot space is defined between the drug-permeable membrane and the exterior wall of the body portion of the microchip element.