Microneedle Array Assembly Uniformity Control Membrane
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Solution Overview
Problem
Existing transdermal drug delivery devices with microneedle arrays face challenges in uniformly administering liquid formulations across a broad area at a relatively low pressure and constant rate, often resulting in inefficient distribution due to variations in flow resistance and bubble pressures among microneedles.
Innovation Solution
A microneedle array assembly is designed with a uniformity control membrane that has significantly higher resistance to flow than the microneedle array itself, ensuring that the liquid formulation is administered through a majority of the microneedles by capillary action, thereby increasing the number of participating microneedles and improving distribution uniformity across a broad area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a microneedle array is used for transdermal delivery, then pain to the patient is reduced, but uniform distribution of liquid formulation across a broad area is difficult to achieve
Solution Approach 1:
A uniformity control membrane is introduced as an intermediary component between the liquid formulation source and the microneedle array. This membrane has flow resistance properties that differ from the microneedle array, creating a pressure gradient that ensures uniform distribution of liquid formulation across all microneedles, thereby achieving both pain reduction and distribution uniformity
2Productivity
If liquid formulation is delivered at high pressure, then flow rate is increased, but administration uniformity across microneedles deteriorates
Solution Approach 1:
The flow resistance parameter of the uniformity control membrane is specifically designed to create an optimal pressure gradient. By controlling the pressure distribution through the membrane's resistance characteristics, the system achieves uniform liquid formulation administration across the microneedle array at relatively low pressures, maintaining both flow rate and administration uniformity
3Quantity of substance
If conventional needle is used for subcutaneous delivery, then large amounts of fluidic drug can be delivered at one time, but pain to the patient increases and steady state concentration is difficult to maintain
Solution Approach 1:
The single conventional needle is segmented into multiple microneedles arranged in an array. This segmentation allows the same total quantity of fluidic drug to be delivered through many smaller needles simultaneously, reducing patient pain while maintaining the ability to deliver large amounts of drug. The uniformity control membrane ensures all microneedles contribute equally, achieving both pain reduction and steady state concentration
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
This configuration enhances the uniformity and efficiency of drug delivery by increasing the number of participating microneedles, ensuring a consistent and broad administration of the liquid formulation at low pressure, which improves the drug's effectiveness on the body.
Implementation Method 1
the liquid formulations are administered by way of capillary action
Implementation Method 2
the resistance to flow through the uniformity control membrane is substantially greater than the resistance to flow through the microneedle array
Data Source
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AI summary
A microneedle array assembly (71; 171), comprising: a microneedle array (28; 128) comprising a base having opposite upstream and downstream sides (37, 40) and defining a plurality of apertures (43) extending between the upstream and downstream sides (37,40); and a plurality of microneedles (31; 131) extending from the downstream side (40); wherein each of the plurality of apertures (43) are defined in the base proximate each of the plurality of microneedles (31; 131), and wherein the resistance to flow through the upstream side of the base (34) is at least about 30 times greater than resistance to flow through the microneedle array (28; 128), wherein the at least about 30 times greater is a difference in the resistance to flow between the upstream side (37) and the downstream side (40) of the base.