Segmented Microneedle Array for Controlled Drug Delivery and Pain Reduction

Solution Overview

Problem

Existing microneedle injection tools have limited blood flow promotion and drug delivery efficiency due to restricted insertion depth and lack of control over protrusion density and distribution, leading to suboptimal pain reduction and drug absorption.

Innovation Solution

An injection needle with a combination of first protrusions having openings for drug delivery, second protrusions for blood flow promotion, and third protrusions acting as insertion depth controllers, arranged in specific patterns to control insertion depth and density, enhancing both drug injection and blood flow stimulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If microneedles are inserted deeper into the skin to improve drug delivery efficiency, then drug absorption is improved, but pain increases and dermal penetration becomes excessive

Engineering Contradiction:

Improvedrug delivery efficiencyVSAvoidpain

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The microneedle array is segmented into multiple protrusions with different heights (first protrusions at 1-2mm for pain reduction, second protrusions at 0.5-1.5mm for drug delivery). This segmentation allows different functional zones within the same injection tool, enabling shallow insertion for pain reduction while maintaining effective drug delivery capability through the appropriately positioned hollow protrusions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the microneedle array have different properties: the first protrusions are designed with specific height and shape for pain reduction, while the second hollow protrusions are designed for drug delivery. The base sheet also has specific structural properties. This local differentiation of qualities allows each component to optimize its function while working together as a system.

Inventive Principle:

Principle #3Local quality

2Productivity

If microneedle density is increased to improve drug delivery coverage, then drug absorption is improved, but insertion depth control becomes more difficult

Engineering Contradiction:

Improvedrug absorptionVSAvoidinsertion depth control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The microneedle array is segmented into multiple protrusions with different heights (first protrusions at 1-2mm for pain reduction, second protrusions at 0.5-1.5mm for drug delivery). This segmentation allows different functional zones within the same injection tool, enabling shallow insertion for pain reduction while maintaining effective drug delivery capability through the appropriately positioned hollow protrusions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention specifies precise parameter ranges for different protrusion heights (first protrusions: 1-2mm, second protrusions: 0.5-1.5mm) and provides formulas for calculating optimal microneedle density based on needle diameter and insertion depth. These parameter changes and relationships enable controlled insertion depth while maintaining effective drug delivery coverage.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If microneedle insertion depth is reduced to minimize pain, then pain reduction is improved, but drug delivery efficiency decreases

Engineering Contradiction:

Improvepain reductionVSAvoiddrug delivery efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The microneedle array is segmented into multiple protrusions with different heights (first protrusions at 1-2mm for pain reduction, second protrusions at 0.5-1.5mm for drug delivery). This segmentation allows different functional zones within the same injection tool, enabling shallow insertion for pain reduction while maintaining effective drug delivery capability through the appropriately positioned hollow protrusions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first protrusions are designed to make initial contact with the skin surface first, performing the preliminary action of penetrating the stratum corneum and creating access pathways. This preliminary action reduces the resistance for subsequent drug delivery through the hollow second protrusions, enabling effective drug delivery at reduced insertion depths.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20240269395A1Injection needle

Publication Date: 2024.08.15 KAO CORP

AI summary

An injection needle includes: protrusions that protrude from a sheet base. The protrusions include a first protrusion having an opening at a tip end portion and being hollow, a second protrusion having no opening at a tip end portion; and an insertion depth controller provided at an intermediate position lower than a tip end position of the first protrusion and higher than a surface of the sheet base. A difference in height between the tip end position of the first protrusion and a position of the insertion depth controller is preferably 1 μm or more and 5 000 μm or less.