Intra-vaginal Ring Segmented Skin for Multi-Drug Release

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Solution Overview

Problem

Current intra-vaginal ring (IVR) drug delivery systems face challenges in simultaneously releasing two or more therapeutic agents with controlled release rates, stability, and manufacturing complexity, often resulting in ineffective therapeutic outcomes due to limitations in drug solubility and diffusion coefficients.

Innovation Solution

The IVR system incorporates a core with a first therapeutic agent dissolved in a thermoplastic polymer and a skin with a second therapeutic agent in solid form, where the skin has varying portions with different permeability properties, allowing for independent adjustment of release rates and achieving a near zero-order release profile by utilizing a hybrid reservoir-matrix system configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single skin is used to control release of both crystalline and dissolved drugs, then the structure is simple, but the release rates of multiple drugs cannot be independently adjusted

Engineering Contradiction:
Improvestructure simplicityVSAvoidindependent release rate adjustment
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The skin is divided into two distinct portions: a first skin portion controlling release of the crystalline drug and a second skin portion controlling release of the dissolved drug. This segmentation allows each portion to be independently optimized for its specific drug, enabling independent adjustment of release rates while maintaining overall system simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the skin are assigned different properties (thickness, permeability, composition) tailored to the specific requirements of each drug. The first skin portion has properties optimized for the crystalline drug while the second skin portion has properties optimized for the dissolved drug, allowing local optimization without compromising the other.

Inventive Principle:
Principle #3Local quality

2Productivity

If thin skin is applied to increase release rate of crystalline drug, then release rate increases, but amount of dissolved drug becomes too small resulting in early depletion

Engineering Contradiction:
Improverelease rateVSAvoidrelease duration
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The skin is segmented into two portions with different thicknesses: a thinner first skin portion for the crystalline drug to achieve higher release rates, and a thicker second skin portion for the dissolved drug to maintain sustained release and prevent early depletion. This allows each drug to have its release rate and duration independently optimized.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thickness parameter of the skin is varied across different portions to achieve different release characteristics. The first skin portion has a smaller thickness parameter to increase release rate, while the second skin portion has a larger thickness parameter to extend release duration and prevent depletion.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple drugs are released from one device, then therapeutic efficacy is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvetherapeutic efficacyVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple drugs with different release requirements are merged into a single IVR device with a unified core and segmented skin structure. This allows simultaneous delivery of multiple therapeutic agents from one device, improving therapeutic efficacy while the segmented design keeps manufacturing relatively simple by using a modular approach.

Inventive Principle:
Principle #5Merging (Combining)

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 stable and controlled simultaneous release of multiple therapeutic agents over an extended period, improving the therapeutic efficacy and stability of the IVR system while reducing manufacturing complexity.

Implementation Method 1

The release of the crystalline drug and the dissolved drug loaded in the reservoir is governed by the same skin; hence, by varying skin properties the release of the crystalline drug and the dissolved drug will be tuned in the same direction

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a drug-loaded thermoplastic polymer core, (ii) a drug-loaded thermoplastic polymer intermediate layer

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentEP3079660B1Drug delivery system
Publication Date: 2021.03.03 MERCK SHARP & DOHME BV
  • EP3079660B1 patent drawingFigure 1
  • EP3079660B1 patent drawingFigure 2
  • EP3079660B1 patent drawingFigure 3

AI summary

Described herein is an intra-vaginal 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, wherein the first therapeutic agent is less permeable in the second thermoplastic polymer than the first thermoplastic polymer, and a second therapeutic agent in solid form, wherein the second therapeutic agent is loaded in a portion of the skin.