Naltrexone Transdermal Patch Using Cross-Linked PEO Hydrogel

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Solution Overview

Problem

Current methods for delivering naltrexone, particularly low-dose naltrexone (LDN), face challenges such as poor oral bioavailability and inefficiencies in transdermal delivery, including incomplete drug delivery with microneedles and short delivery times with iontophoresis, necessitating an improved method for sustained release and higher dosing.

Innovation Solution

A transdermal patch comprising a cross-linked poly(ethylene oxide) hydrogel loaded with naltrexone, formed by mixing an aqueous solution of poly(ethylene oxide) and naltrexone, adding a cross-linking agent, drying to form a xerogel, and irradiating under UV to create cross-linking, which is then swollen to form the hydrogel, providing a controlled release dosage form.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If microneedles are used for transdermal delivery of naltrexone, then drug delivery can be achieved, but the delivery may be incomplete due to incorrect application

Engineering Contradiction:
Improvedrug delivery completenessVSAvoidapplication correctness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent uses a disposable microneedle patch where the microneedles are designed to be used once and then discarded. This ensures that each patch maintains its integrity and functionality until use, eliminating the risk of incorrect application from reused or damaged needles while providing a simple, single-use solution for patients

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

2Duration of action of moving object

If iontophoresis is used for transdermal delivery of naltrexone, then drug delivery can be achieved, but the delivery time is much shorter than required for sustained release

Engineering Contradiction:
Improvedelivery timeVSAvoiddelivery rate
Core Design Contradiction:
Duration of action of moving objectVSProductivity

Solution Approach 1:

The patent employs microneedles that dynamically transition from an intact state during application to a dissolving state after penetration. The microneedles are designed to dissolve at a controlled rate after insertion, providing sustained drug release over multiple days rather than immediate release, thus balancing delivery rate with duration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state of the microneedles from solid to dissolved form over time. By controlling the dissolution rate and drug loading concentration, the system transitions from high initial delivery to sustained lower-level release, achieving both adequate delivery rate and extended duration

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If high dosing of naltrexone is required, then therapeutic effectiveness can be achieved, but existing transdermal methods cannot deliver sufficient quantities

Engineering Contradiction:
Improvenaltrexone dosageVSAvoiddelivery efficiency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent nests the drug naltrexone within the microneedle structure itself. The microneedles are composed of or loaded with the drug, allowing the entire needle to serve as a drug reservoir. This nested design maximizes the quantity of drug that can be delivered through the small transdermal interface, enabling high dosing while maintaining reliable delivery efficiency

Inventive Principle:
Principle #7Nested doll (Nesting)

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 patch achieves effective transdermal delivery of naltrexone with improved mechanical strength and dosing performance, enabling sustained release over several days, addressing the limitations of existing delivery methods by providing a therapeutically effective amount for conditions like opioid dependency and autoimmune disorders.

Implementation Method 1

The patch achieves effective transdermal delivery of naltrexone with improved mechanical strength and dosing performance, enabling sustained release over several days

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

irradiating the xerogel under UV radiation to create cross-linking

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP4051247B1Transdermal patch
Publication Date: 2023.11.01 UNIVERSITY OF SUNDERLAND
  • EP4051247B1 patent drawingFigure 1~2B
  • EP4051247B1 patent drawingFigure 3~4
  • EP4051247B1 patent drawingFigure 5~6

AI summary

A transdermal patch is provided, wherein the patch comprises a cross-linked poly(ethylene oxide) hydrogel loaded with naltrexone, or a pharmaceutically acceptable salt or solvate thereof, and an occlusive adhesive tape. The poly(ethylene oxide) hydrogel has a crosslink density of at least 4.5×10-4 mol cm-3 and not more than 16×10-4 mol cm-3. Also provided are methods for preparing naltrexone-loaded cross-linked poly(ethylene oxide) hydrogels, transdermal patches for use as a medicament, for example in the treatment of a specified condition with LDN therapy.