Reverse Microemulsion Transdermal Delivery of Hydrophilic Agents

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Solution Overview

Problem

Current transdermal delivery methods face challenges in effectively delivering hydrophilic biologically-active agents through the skin due to their insolubility in traditional hydrophobic solvents, leading to inefficiencies and discomfort during application.

Innovation Solution

A composition using a reverse microemulsion system with a hydrophobic, volatile solvent and a reverse emulsion surfactant solubilizes hydrophilic agents, allowing for non-stinging, painless penetration through the skin, utilizing hexamethyldisiloxane as a solvent and sodium bis(2-ethylhexyl)sulfosuccinate as a surfactant to form a stable, clear solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydrophilic biologically-active agents are delivered using traditional hydrophobic solvents, then transdermal delivery can be achieved, but the agents are insoluble in the solvents leading to delivery inefficiency

Engineering Contradiction:
Improvetransdermal delivery efficiencyVSAvoidsolubility of hydrophilic agents
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent uses reverse emulsion surfactants as intermediary substances that enable hydrophilic biologically-active agents to be solubilized in hydrophobic volatile solvents. The surfactant forms a bridge between the polar agent and nonpolar solvent, creating a stable reverse microemulsion system that resolves the solubility contradiction while maintaining transdermal delivery capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical-chemical parameters of the delivery system by using reverse microemulsions with specific HLB values (3-11) and controlling the water content (0-10 wt%) to achieve optimal solubility of hydrophilic agents in hydrophobic solvents. This parameter optimization enables both solubility and transdermal penetration.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If volatile hydrophobic solvents are used for transdermal delivery, then rapid evaporation and non-stinging application are achieved, but hydrophilic agents cannot be solubilized

Engineering Contradiction:
Improveapplication comfortVSAvoidsolubility of hydrophilic agents
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Reverse emulsion surfactants serve as mediators that allow hydrophilic agents to be incorporated into volatile hydrophobic solvent systems without compromising application comfort. The surfactant enables solubilization while the volatile solvent maintains rapid evaporation and non-stinging properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite delivery system combining volatile hydrophobic solvent, reverse emulsion surfactant, and hydrophilic biologically-active agent. This composite formulation achieves both solubility of polar agents and the desirable application characteristics of volatile hydrophobic solvents.

Inventive Principle:
Principle #40Composite materials

3Reliability

If reverse microemulsion is used to solubilize hydrophilic agents, then solubility is improved, but the system complexity increases

Engineering Contradiction:
Improvesolubility of hydrophilic agentsVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies the reverse microemulsion system by optimizing key parameters: using surfactants with HLB values of 3-11, limiting water content to 0-10 wt%, and selecting volatile solvents with specific properties. These parameter constraints reduce formulation complexity while maintaining solubility effectiveness.

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 method enables efficient, rapid, and sustained transdermal delivery of hydrophilic agents, overcoming solubility issues and providing a conformal coating that maintains efficacy and comfort during application and healing.

Implementation Method 1

hydrophilic, polar, biologically active agents that are solubilized by a reverse emulsion surfactant into a microemulsion

Methodology Applied
Scientific EffectReverse microemulsion: Microemulsion

Implementation Method 2

solubilizing them in a reverse microemulsion

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 3

penetrating the stratum corneum of the skin

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 4

Transdermal delivery is augmented by the addition of a penetration enhancer

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 5

volatile, hydrophobic solvent... after solvent evaporation

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2916820B1Delivery of biologically-active agents using volatile, hydrophobic solvents
Publication Date: 2023.10.11 ROCHAL TECHNOLOGIES LLC

AI summary

A composition and method adapted for delivery of hydrophilic, biologically-active agents are disclosed. The composition can include a reverse microemulsion formed from at least one hydrophilic, biologically-active agent solubilized by a hydrophobic reverse emulsion surfactant in a non-stinging, volatile, hydrophobic solvent. The non-stinging, volatile, hydrophobic solvent is selected from the group consisting of volatile linear and cyclic siloxanes, volatile linear, branched, and cyclic alkanes, volatile fluorocarbons and chlorofluorocarbons, liquid carbon dioxide under pressure, and combinations thereof. The reverse microemulsion can be an optically clear solution.