Self-supporting Tri-layer Films for Therapeutic Agent Delivery

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Solution Overview

Problem

Current methods for delivering therapeutic agents through implantable medical devices are limited by the use of water-soluble drugs, which face challenges in controlled release due to limited solubility in hydrophobic systems, resulting in poor encapsulation efficiencies and limited therapeutic payloads.

Innovation Solution

Self-supporting tri-layer films comprising a hydrophobic polymer and a water-soluble therapeutic agent, with a tensile strength ranging from 500 kPa to 100 MPa, allowing for a high therapeutic payload of 800 µg/cm² to 50 mg/cm², formed by ultrasonic spraying and not requiring a common solvent, enabling enhanced drug loading and controlled release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If water-soluble drugs are used in conventional coating methods, then the drugs can be easily formulated, but the encapsulation efficiency and therapeutic payload are limited due to poor solubility in hydrophobic polymer systems

Engineering Contradiction:
Improvetherapeutic payloadVSAvoidencapsulation efficiency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The coating is divided into multiple layers with different functions: a hydrophobic polymer layer for structural integrity and controlled release, and a hydrophilic layer for high drug loading capacity. This segmentation allows each layer to optimize its specific function without compromise

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite coating structure combining hydrophobic and hydrophilic materials. The hydrophobic polymer matrix provides mechanical strength and controlled release properties, while the hydrophilic component enables high solubility and loading of water-soluble therapeutic agents

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If highly water-soluble drugs are used, then the drugs can be easily administered, but they offer limited solubility in organic systems and require sufficient water barrier to sustain release

Engineering Contradiction:
Improvedrug formulation easeVSAvoidsustained release duration
Core Design Contradiction:
Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The coating is segmented into functional layers where the hydrophobic polymer layer acts as a water barrier to control drug release kinetics, while the hydrophilic layer maintains drug solubility. This layered structure enables both ease of formulation and sustained release

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the coating have different properties: the hydrophobic polymer matrix provides water barrier properties in specific zones, while hydrophilic domains provide drug solubility. This local differentiation of properties resolves the contradiction between solubility and sustained release

Inventive Principle:
Principle #3Local quality

3Strength

If thin surface coatings are applied to medical devices, then the devices maintain flexibility, but the therapeutic payload is limited

Engineering Contradiction:
Improvecoating mechanical strengthVSAvoidtherapeutic payload
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The composite coating structure combines a thin hydrophobic polymer layer for mechanical strength with a hydrophilic layer for high drug capacity. This allows the coating to be thin yet maintain both structural integrity and high therapeutic payload

Inventive Principle:
Principle #40Composite materials

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 tri-layer films provide a high therapeutic payload and controlled release of drugs like bupivacaine HCl, surpassing conventional methods such as dip coating, with increased mechanical strength and flexibility, allowing for effective drug delivery without the need for additional support.

Implementation Method 1

Both solutions are fed into an ultrasonic sprayer and passed through at least one ultrasonic spray nozzle. The nozzle vibrates at a frequency of about 48 kHz

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

The self-supporting tri-layer films include at least one hydrophobic polymer and at least one water-soluble therapeutic agent

Methodology Applied
Scientific EffectHydrophobic interaction: Hydrophobe

Data Source

PatentEP2444075B1Self-supporting films for delivery of therapeutic agents
Publication Date: 2018.09.05 COVIDIEN LP
  • EP2444075B1 patent drawingFigure 1~2C
  • EP2444075B1 patent drawingFigure 3A~3F
  • EP2444075B1 patent drawingFigure 4A~5

AI summary

The present disclosure relates to self-supporting films for delivery of a therapeutic agent containing at least one hydrophobic polymer and at least one therapeutic agent. Methods of forming the self-supporting films are also disclosed.