Particle-Attached Microneedles for Stable Solid-Drug Coating

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Solution Overview

Problem

Conventional microneedle manufacturing methods face challenges such as drug denaturation, phase separation, and lengthy drying processes when preparing liquid formulations, which affect the mechanical strength and delivery efficiency of active drugs.

Innovation Solution

A method of manufacturing microneedles by attaching solid-phase drug particles directly onto the microneedle surface using an adhesive layer, eliminating the need for liquid formulations and reducing voids between particles through techniques like air blow or PDMS molds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a liquid formulation is used to load drug into microneedle, then the microneedle can be manufactured by coating or molding process, but the drug may be denatured during preparation and drying process

Engineering Contradiction:
Improvemanufacturing processVSAvoiddrug stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the physical state of the drug from liquid formulation to solid particles. This parameter change eliminates the need for dissolution, stabilizer addition, and drying processes that cause drug denaturation, while still allowing coating manufacturing processes to be used.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts the drug from liquid formulation and uses it in solid particle form directly. This removes the harmful liquid medium and associated processing steps (dissolution, stabilization, drying) that compromise drug reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Quantity of substance

If a highly concentrated drug solution is prepared to obtain required clinical content, then the drug loading amount is sufficient, but the protein is likely to be denatured

Engineering Contradiction:
Improvedrug loading amountVSAvoiddrug activity
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the drug state from concentrated solution to solid particles. This allows achieving required drug loading amounts without the denaturation risks associated with high-concentration protein solutions.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a drying process is applied to remove liquid formulation, then the microneedle can be formed, but the drying time is lengthy (several minutes to hours)

Engineering Contradiction:
Improvemicroneedle formationVSAvoiddrying time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent extracts and removes the liquid formulation step entirely by using solid particles directly. This eliminates the lengthy drying process while still allowing microneedle formation through coating processes.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If solid-phase particles are attached on microneedle surface, then the drug delivery speed is quick and drying time is reduced, but the particles must be uniformly distributed and adhered

Engineering Contradiction:
Improvedrug delivery speedVSAvoidparticle distribution uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces an adhesive layer as an intermediary between the microneedle surface and solid drug particles. This adhesive mediator ensures uniform distribution and strong adhesion of particles, enabling quick drug delivery while maintaining manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

5Strength

If adhesive layer is applied to attach particles, then the particle adhesion is strong, but the manufacturing process complexity increases

Engineering Contradiction:
Improveparticle adhesionVSAvoidmanufacturing process
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent uses a simple drying process to cure the adhesive layer, changing its state from liquid to solid. This achieves strong particle adhesion without requiring complex manufacturing equipment or processes.

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

This approach allows for quick drug delivery to the skin, maintains drug stability, and enhances user convenience by minimizing the drying time and avoiding chemical changes, while ensuring uniform distribution and adhesion of drug particles.

Implementation Method 1

coating a microneedle with an adhesive solution to form an adhesive layer; and dipping the microneedle, on which the adhesive layer has been formed, in a coating well filled with solid-phase drug particles to secondarily attach the solid-phase drug particles on the adhesive layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

the microneedle secondarily attached with the solid-phase drug particles may be treated with an air blow to remove unattached particles

Methodology Applied
Scientific EffectAir flow: Fluid Spray

Data Source

PatentEP4209246B1Method of manufacturing of a particle-attached microneedle
Publication Date: 2026.02.18 QUADMEDICINE
  • EP4209246B1 patent drawingFigure 1A~1B
  • EP4209246B1 patent drawingFigure 2~3A
  • EP4209246B1 patent drawingFigure 3B~3C

AI summary

Disclosed are a particle-attached microneedle having a solid-phase drug mounted thereon, and a method of manufacturing the particle-attached microneedle. More particularly, the particle-attached microneedle includes a microneedle (10), an adhesive layer (11), solid-phase drug particles (22), a film (21), and a coating well (20).