Sintered Hydroxyapatite Injection Agent Flow Through Thin Needles

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Solution Overview

Problem

Existing cosmetic medical fillers containing hydroxyapatite particles face issues with flow characteristics, requiring large needle diameters, causing pain and inflammation, and particle recognition by macrophages leading to inflammation.

Innovation Solution

Development of a hypodermic injection agent using sintered hydroxyapatite particles with specific particle diameters and a hydrogel, such as carboxymethylcellulose, to improve flow characteristics and prevent reaggregation, allowing use in thin needles and reducing inflammation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If large needle diameter is used for injection, then flow characteristics are improved, but pain and tissue damage occur

Engineering Contradiction:
Improveflow characteristicsVSAvoidpain during injection
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent changes the particle size parameter of hydroxyapatite from conventional large particles (80-200 μm) to fine particles (0.5-5 μm), which fundamentally alters the flow characteristics of the injection agent, enabling it to pass through thin needles while maintaining smooth flow

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a hydrogel carrier system that provides thixotropic properties, allowing the injection agent to exhibit different flow characteristics under different conditions - remaining stable during storage but flowing smoothly during injection through thin needles

Inventive Principle:
Principle #15Dynamics

2Reliability

If large hydroxyapatite particles are used, then biocompatibility is maintained, but inflammation occurs due to macrophage recognition

Engineering Contradiction:
ImprovebiocompatibilityVSAvoidinflammation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the particle size parameter of hydroxyapatite to the fine particle range (0.5-5 μm), which prevents recognition by macrophages as foreign substances, thereby eliminating the inflammatory response while preserving biocompatibility

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If thin needle diameter is used for injection, then pain is reduced, but flow characteristics deteriorate

Engineering Contradiction:
Improvepain during injectionVSAvoidflow characteristics
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent changes the particle size parameter to fine particles (0.5-5 μm) and adjusts the carrier viscosity to create an injection agent that flows smoothly through thin needles (0.20 mm or less internal diameter) without clogging or resistance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The hydrogel carrier provides dynamic flow properties that adapt to the injection process, allowing the agent to flow easily through thin needles while maintaining stability during storage and after injection

Inventive Principle:
Principle #15Dynamics

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 agent exhibits excellent flow characteristics for use in needles with diameters of 0.20 mm or less, minimizing pain and inflammation, while maintaining bioactivity and promoting collagen production for long-term effects.

Implementation Method 1

hydroxyapatite particles with a particle diameter of 0.5 μm or more and 15 μm or less... contained in a hydrogel

Methodology Applied
Scientific EffectSuspension: Suspension

Implementation Method 2

a hydrogel... The agent exhibits excellent flow characteristics for use in needles with diameters of 0.20 mm or less

Methodology Applied
Scientific EffectHydrogel: Hydrogel

Data Source

PatentEP3231433B1Agent for hypodermic injection
Publication Date: 2023.12.27 MOTEJO LTD
  • EP3231433B1 patent drawingFigure 1(a)~1(b)
  • EP3231433B1 patent drawingFigure 2
  • EP3231433B1 patent drawing

AI summary

To provide an agent for hypodermic injection that has excellent flow characteristics, can be used particularly even in thin injection needles, for example with an internal diameter of 0.20 mm or less, and is unlikely to cause pain during injection and inflammation. The agent for hypodermic injection includes a hydrogel containing sintered hydroxyapatite particles, wherein the sintered hydroxyapatite particle content is 1 to 60% by mass based on the total mass of the agent, and the average particle diameter of the sintered hydroxyapatite particles is 15 nm or less.