Vaginal Ring Drug Delivery System with Core-Skin Architecture

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Solution Overview

Problem

Current intra-vaginal ring (IVR) designs face challenges in simultaneously releasing multiple therapeutic agents, such as CCR5 inhibitors and HIV integrase inhibitors, due to stability issues, difficulty in adjusting release rates, manufacturing complexity, and inability to meet therapeutic release criteria, particularly in achieving high release rates for anti-viral drugs.

Innovation Solution

The vaginal ring drug delivery system features a core with a first therapeutic agent dissolved in a thermoplastic polymer and a skin surrounding the core with a second therapeutic agent in solid form, allowing for independent adjustment of release rates and higher diffusion rates due to reduced diffusion length, thereby overcoming the limitations of previous systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a skin surrounds the core in the IVR system, then the release rate of therapeutic agents can be controlled, but the diffusion length increases and release rate decreases

Engineering Contradiction:
Improverelease rate of therapeutic agentsVSAvoiddiffusion length
Core Design Contradiction:
ProductivityVSLength of moving object

Solution Approach 1:

The IVR system is segmented into distinct functional layers: a core layer containing therapeutic agents and a skin layer with controlled permeability. This segmentation allows the core to provide high concentration of drugs while the skin controls release rate, effectively resolving the contradiction between diffusion length and release rate by separating the reservoir function from the rate-control function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the IVR system have different properties optimized for their specific functions. The core region has high drug concentration and permeability for maximum availability, while the skin region has controlled permeability and appropriate thickness for rate control. This local optimization allows simultaneous achievement of high release rate and controlled diffusion.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If multiple therapeutic agents are released from a single IVR device, then comprehensive HIV prevention is achieved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveability to deliver multiple therapeutic agentsVSAvoidcomplexity of multi-drug release system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple therapeutic agents with different release requirements are merged into a single IVR device with a unified multi-layer structure. The core layer accommodates multiple drugs while the skin layer provides unified rate control, enabling comprehensive HIV prevention through combination therapy without requiring multiple separate devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The IVR system is designed as a universal platform capable of delivering multiple therapeutic agents simultaneously. The multi-layer architecture with core and skin components can accommodate various drug combinations for HIV prevention, making the device versatile and adaptable to different treatment protocols without increasing fundamental structural complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the skin thickness is increased to control release rate, then release rate decreases, but stability upon storage and transport improves

Engineering Contradiction:
Improvestability upon storage and transportVSAvoidrelease rate of therapeutic agents
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The skin thickness parameter is optimized to specific ranges that balance storage stability and release rate requirements. By carefully selecting and controlling the skin thickness parameter during manufacturing, the system achieves both adequate protection during storage/transport and sufficient drug release during use, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #35Parameter changes

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 configuration enables sustained release of therapeutic agents over an extended period, achieving the desired therapeutic effect by allowing higher release rates and independent adjustment of drug release, addressing the limitations of previous IVR designs.

Implementation Method 1

higher diffusion rates due to reduced diffusion length

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a skin surrounding the core with a second therapeutic agent in solid form, allowing for independent adjustment of release rates

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3079659B1Drug delivery system for delivery of Anti-virals
Publication Date: 2020.10.28 MERCK SHARP & DOHME BV
  • EP3079659B1 patent drawingFigure 1
  • EP3079659B1 patent drawingFigure 2
  • EP3079659B1 patent drawingFigure 3

AI summary

Described herein is a vaginal ring drug delivery system comprising (i) a core comprising a first thermoplastic polymer and a first therapeutic agent, wherein the first therapeutic agent is dissolved in the first thermoplastic polymer, and (ii) a skin surrounding the core comprising a second thermoplastic polymer and a second therapeutic agent, wherein the second therapeutic agent is in solid form.