Diffusion Cell Head Heating for Extended Temperature Control

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Solution Overview

Problem

Current temperature control systems for diffusion cells, such as those used in in vitro permeation studies, face limitations in maintaining consistent and prolonged elevated temperatures, often relying on short-duration heat packs or inefficient heat transfer methods, which are not suitable for extended studies like those required by FDA guidelines.

Innovation Solution

A temperature control system integrated into the cell head of a diffusion cell, utilizing a fluid heat exchanger and a thermostat to maintain temperatures between 37° C and 51° C, ensuring reliable and constant temperature control through direct contact with the dermal dosage form and membrane, eliminating the need for external heat packs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If heat packs or textile fabrics are used for temperature control, then elevated temperature can be achieved, but the duration of heat generation is limited in time

Engineering Contradiction:

Improvetemperature of cell headVSAvoidduration of heat generation

Core Design Contradiction:

TemperatureVSDuration of action of moving object

Solution Approach 1:

The patent applies a fluid-based heating system where a heating fluid circulates through a heat exchanger in thermal contact with the cell head. This hydraulic approach replaces the chemical reaction-based heat packs, enabling continuous temperature maintenance through fluid circulation rather than limited chemical reaction duration.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The system ensures continuous heating action by circulating heating fluid through the heat exchanger. The fluid continuously absorbs heat from the heating element and transfers it to the cell head, maintaining uninterrupted thermal contact and eliminating the time limitation inherent in chemical heat packs.

Inventive Principle:

Principle #20Continuity of useful action

2Temperature

If heat packs are used for temperature control, then elevated temperature can be achieved, but the system becomes unsuitable for extended studies

Engineering Contradiction:

Improvetemperature of cell headVSAvoidreliability for extended studies

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The hydraulic heating system with continuous fluid circulation provides reliable temperature control for extended studies. The system can maintain stable temperatures over prolonged periods through controlled fluid flow, unlike chemical heat packs that deplete their reaction over time.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The system incorporates temperature sensing and control mechanisms that monitor the cell head temperature and adjust heating fluid flow accordingly. This feedback control ensures consistent temperature maintenance throughout extended study durations, enhancing reliability.

Inventive Principle:

Principle #23Feedback

3Power

If chemical heat packs are used, then heat generation can be obtained by chemical reaction, but the duration of heat generation is limited in time

Engineering Contradiction:

Improveheat generation capabilityVSAvoidduration of heat generation

Core Design Contradiction:

PowerVSDuration of action of moving object

Solution Approach 1:

The patent replaces the chemical reaction system with a thermal conduction-based heating system. Instead of relying on chemical reactions (pyrophoric iron oxidation), the system uses a heating element that transfers thermal energy through a heat exchanger to the cell head, providing a non-consumable heat source.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The heating fluid circulation system enables continuous heat transfer from the heating element to the cell head. The fluid continuously absorbs and delivers thermal energy, maintaining uninterrupted heating action throughout the study duration without chemical depletion.

Inventive Principle:

Principle #20Continuity of useful action

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 solution provides improved and sustained temperature control, enhancing the efficiency of in vitro permeation studies by maintaining optimal conditions for extended periods, as demonstrated by statistically significant increases in release rates of active ingredients compared to standard systems.

Implementation Method 1

a cell head (12), in particular designed as a donor chamber, and a temperature control device (13) connected to the cell head (12), in particular with at least physical contact between the cell head (12) and the temperature control device (13)

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The temperature control device (13) is configured to control the temperature of the cell head (12)

Methodology Applied

Scientific EffectThermal equilibrium:

Data Source

PatentUS20230417642A1Temperature Control System for a Diffusion Cell, Diffusion Cell, Diffusion Cell System, and Method for Controlling the Temperature in a Diffusion Cell

Publication Date: 2023.12.28 LTS LOHMANN THERAPIE SYST AG

AI summary

A temperature control system for a diffusion cell. The temperature control system includes a cell head and a temperature control device connected to the cell head. Moreover, a diffusion cell having such a temperature control system. Furthermore a diffusion cell system having such a temperature control system or such a diffusion cell. Finally, a method for controlling the temperature of a cell head of a diffusion cell, including introducing the temperature control fluid into the cell head.