Biodegradable Protection Layer for Water-Soluble Drug Release

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Solution Overview

Problem

Current medical devices struggle to effectively administer water-soluble therapeutic agents to their intended site while protecting them during transport and controlling the release duration, particularly in the context of vascular restenosis treatment.

Innovation Solution

An implantable medical device with a biocompatible and biodegradable protection/retention layer, comprising a film-forming agent and a hydrophobic agent, is used to protect and control the release of a water-soluble therapeutic agent, which is deposited in microreservoirs on the device's surface, ensuring the agent remains effective until it reaches the implantation site.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a water-soluble therapeutic agent is administered using current medical devices, then the agent can be delivered to the intended site, but the agent suffers from premature loss or release during transport and cannot control the release duration

Engineering Contradiction:
Improveprotection of therapeutic agentVSAvoidrelease duration control
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies a protective film layer composed of a film-forming agent and hydrophobic agent that coats the therapeutic agent in the reservoirs. This thin film structure protects the water-soluble agent during transport while controlling its release duration through the hydrophobic properties of the film, resolving the contradiction between reliable protection and controlled release timing.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The protective layer is formed as a composite material combining a film-forming agent (such as gelatin, albumin, or synthetic polymers) with a hydrophobic agent (such as wax or oil). This composite structure provides both the necessary protection for water-soluble agents and controlled release characteristics, addressing both reliability and duration control requirements.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the therapeutic agent is protected during transport, then premature loss is prevented, but the release mechanism becomes more complex

Engineering Contradiction:
Improveprotection of therapeutic agentVSAvoidprotection layer composition
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies the surface properties of the protective layer by incorporating hydrophobic agents, which changes the interaction between the protective film and the aqueous environment. This parameter change (hydrophobicity) provides both protection and controlled release functionality without requiring complex mechanical structures, thus maintaining relatively simple device complexity while achieving reliable protection.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If microreservoirs are used to contain the therapeutic agent, then controlled delivery is achieved, but the surface area for release is limited

Engineering Contradiction:
Improvecontrolled deliveryVSAvoidrelease surface area
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent divides the therapeutic agent into multiple discrete microreservoirs distributed across the device surface. Each reservoir acts as an independent containment unit, enabling precise control over drug delivery timing and location. The segmentation allows controlled delivery while the distributed arrangement across the surface compensates for the limited individual reservoir area.

Inventive Principle:
Principle #1Segmentation

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 solution ensures the therapeutic agent is protected and released in a controlled manner, enhancing treatment efficacy and preventing premature loss or release, thereby effectively addressing the challenges of administering water-soluble agents in medical devices.

Implementation Method 1

at least one hydrophobic agent, preferably biocompatible, making it possible to control the speed of degradability of the protective or retention layer

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

said layer comprising a biocompatible and biodegradable film-forming agent

Methodology Applied
Scientific EffectFilm formation: Coatings

Data Source

PatentEP2249892B1Implantable medical device including a protection/retaining layer for an active ingredient or drug, in particular a water-soluble one
Publication Date: 2017.11.15 HEXACATH
  • EP2249892B1 patent drawingFigure 1~3

AI summary

The invention relates to an implantable medical device (10) that includes an active ingredient or drug, particularly a water-soluble one (36), characterised in that said medical device (10) includes a means (30) for receiving said active ingredient or drug in the form of a solid deposit, and at least one biocompatible and biodegradable protection/retaining layer (38) for protecting the active ingredient or drug (36) until the implantation site thereof, wherein said biocompatible and biodegradable protection layer (38) includes at least one film-forming biocompatible and biodegradable agent and at least one hydrophobic, preferably biocompatible, agent for controlling the disintegration rate of the protection/retaining layer. The invention provides better protection of the active ingredient or drug, and better control of the disintegration rate of the protection/retaining layer.