Risperidone Transdermal Matrix Patch for Steady 14-Day Delivery

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Solution Overview

Problem

Existing transdermal administration systems for risperidone struggle to deliver the drug continuously at a therapeutically effective amount for 24 hours to 14 days without causing skin irritation or adverse effects, and there is a need for a system that can maintain a constant rate of drug delivery to avoid peak levels and side effects.

Innovation Solution

A matrix-type transdermal administration system using lauryl lactate and long-chain fatty alcohols as skin penetration enhancers, combined with micronized risperidone crystal form A, to achieve sustained and controlled drug release for up to 14 days, maintaining a therapeutically effective blood drug concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If transdermal patch preparations are designed for long-term wear (7 days or more), then patient compliance and ease of operation are improved, but skin irritation and skin adhesion problems occur

Engineering Contradiction:
Improvepatient complianceVSAvoidskin irritation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the penetration enhancer by selecting long-chain fatty acids with specific chain lengths (C16-C22) and specific molecular structures (saturated or monounsaturated). This parameter optimization allows the patch to maintain effective drug delivery while reducing skin irritation, enabling safe long-term wear of 7-14 days.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite matrix system combining hydrophilic polymers (hydroxypropyl cellulose, carbomer) with lipophilic penetration enhancers (long-chain fatty acids). This composite material approach creates a balanced formulation that provides both sustained drug release and skin tolerance for extended wear periods.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the transdermal patch delivers drug at high concentration, then therapeutically effective blood drug concentration is achieved, but peak levels and side effects increase

Engineering Contradiction:
Improvetherapeutic efficacyVSAvoidside effects
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent creates a dynamic drug release system using a matrix formulation that adjusts drug release rate based on skin penetration conditions. The combination of hydrophilic polymer matrix and lipophilic penetration enhancers creates a controlled release profile that maintains steady blood drug concentrations without sharp peaks, reducing side effects while ensuring therapeutic efficacy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent optimizes the concentration parameters of both the drug (risperidone 2-10 mg/g) and the penetration enhancer (long-chain fatty acid 5-30 mg/g) to achieve optimal drug delivery. This parameter optimization ensures sufficient drug delivery for therapeutic effect while avoiding excessive concentrations that would cause peak-related side effects.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If penetration enhancer concentration is increased to improve drug delivery, then transdermal flux is improved, but skin irritation increases

Engineering Contradiction:
Improvetransdermal fluxVSAvoidskin irritation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent identifies and applies the critical parameter of fatty acid chain length (C16-C22) and saturation level to optimize penetration enhancer performance. Long-chain saturated or monounsaturated fatty acids provide sufficient transdermal flux for effective drug delivery while their specific molecular structure reduces skin irritation compared to shorter-chain or polyunsaturated alternatives.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies the concept of local quality by selecting penetration enhancers with specific molecular characteristics (long-chain, saturated or monounsaturated fatty acids) that are tailored to work effectively with risperidone while being gentle on the skin. This localized optimization of enhancer properties achieves the right balance between flux and tolerance.

Inventive Principle:
Principle #3Local quality

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 system ensures stable and continuous delivery of risperidone at a constant rate, reducing skin irritation and side effects, improving patient compliance and therapeutic efficacy for conditions like schizophrenia.

Implementation Method 1

A matrix-type transdermal administration system using lauryl lactate and long-chain fatty alcohols as skin penetration enhancers

Methodology Applied
Scientific EffectSkin penetration enhancement: Permeation

Implementation Method 2

combined with micronized risperidone crystal form A, to achieve sustained and controlled drug release for up to 14 days

Methodology Applied
Scientific EffectDrug diffusion: Diffusion

Data Source

PatentEP4647074A1Transdermal administration system for risperidone, and preparation method therefor and use thereof
Publication Date: 2025.11.12 NOVASTAGE PHARM (SHENZHEN) LTD
  • EP4647074A1 patent drawingFigure 1~3
  • EP4647074A1 patent drawingFigure 4A
  • EP4647074A1 patent drawingFigure 4B

AI summary

The present invention relates to a risperidone transdermal administration system. More specifically, the present invention relates to a transdermal administration system for continuously delivering risperidone or a pharmaceutically acceptable salt thereof at a therapeutically effective amount of blood drug concentration within 24 hours to 14 days, and a preparation method therefor and a use thereof.