Soluble Microneedle Tip Diameter and Aspect Ratio Optimization

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Solution Overview

Problem

Existing microneedle technologies face challenges in achieving high skin perforation and permeation rates without applying strong force, often resulting in bending, breaking, or inadequate delivery of target materials due to issues with tip diameter, aspect ratio, and density.

Innovation Solution

A soluble microneedle with a tip diameter of 20 µm or smaller and an aspect ratio of 1-5, combined with a compressive yield strength of 10 kN/cm² or higher, is developed, along with a microneedle patch design that maintains mechanical strength and dissolves in the skin for efficient delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the microneedle tip diameter is reduced to improve skin perforation rate, then the skin permeation rate increases, but the microneedle becomes more prone to bending and breaking

Engineering Contradiction:
Improveskin perforation rateVSAvoidmicroneedle structural integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent optimizes the tip diameter parameter to 20 µm or smaller to improve skin perforation efficiency while maintaining sufficient structural strength through controlled aspect ratio and material composition, resolving the contradiction between perforation performance and structural integrity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The microneedle employs composite material composition with controlled mechanical properties to achieve both high tip strength for reliable skin penetration and appropriate dissolvability for drug delivery, preventing both breakage and ensuring functionality

Inventive Principle:
Principle #40Composite materials

2Productivity

If the microneedle aspect ratio is increased to improve skin perforation efficiency, then the delivery efficiency improves, but the microneedle becomes more prone to bending

Engineering Contradiction:
Improvedelivery efficiencyVSAvoidmicroneedle resistance to bending
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent defines an optimized aspect ratio range of 1-5 that balances penetration efficiency with structural stability, preventing bending while ensuring effective drug delivery to the skin

Inventive Principle:
Principle #35Parameter changes

3Productivity

If strong force is applied to ensure skin perforation, then the perforation rate increases, but the microneedle breaks or causes pain

Engineering Contradiction:
Improveperforation rateVSAvoidpain and microneedle breakage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The microneedle's tip diameter and compressive yield strength are optimized to enable perforation with minimal applied force, eliminating the need for strong compression that would cause pain or breakage while maintaining high perforation efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The microneedle is designed as a disposable device with controlled dissolvability, intended to dissolve after single-use perforation and drug delivery, eliminating the need for complex retrieval mechanisms and reducing operational complexity

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Quantity of substance

If the microneedle is made to dissolve in skin for target material delivery, then the drug delivery effectiveness improves, but the microneedle may bend or break before delivery

Engineering Contradiction:
Improvetarget material deliveryVSAvoidmicroneedle structural stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The microneedle's mechanical strength parameters (compressive yield strength ≥10 kN/cm²) and aspect ratio are controlled to maintain structural stability during insertion, while the material composition enables controlled dissolution after penetration to ensure complete drug delivery

Inventive Principle:
Principle #35Parameter changes

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 microneedle effectively perforates the skin and delivers target materials without bending or breaking, ensuring high skin permeation rates and efficient delivery of substances regardless of their location within the microneedle.

Implementation Method 1

a microneedle used to perforate skin which, when inserted through the perforated skin, is dissolved, thereby administering a target material inside the microneedle into the skin

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentEP3441106B1Microneedle structure for efficient skin perforation
Publication Date: 2021.01.20 LG HOUSEHOLD & HEALTH CARE LTD
  • EP3441106B1 patent drawingFigure 1a~1b
  • EP3441106B1 patent drawingFigure 2(a)~3(b)
  • EP3441106B1 patent drawingFigure 4~5

AI summary

The present invention relates to a soluble microneedle and, more particularly, to a microneedle and a microneedle patch comprising the same, wherein the microneedle is used to perforate skin, and the microneedle, when inserted through the perforated skin, is then dissolved, thereby administering the target material from inside the microneedle into the skin. The microneedle according to the present invention, when used, has appropriate levels of mechanical strength, viscosity, and hardness and can be easily inserted into skin without undergoing shape change, for example, bending or breaking, thereby enabling efficient skin perforation. In addition, as the microneedle according to the present invention is dissolved through the perforated skin, the target material penetrates the skin at an excellent ratio. Accordingly, there is no need to apply strong force, and the target material can be effectively delivered into the skin regardless of which part of the microneedle contains the target material.