Flow-through system effects on in vitro analysis of transdermal systems

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Biomaterials Science

Background:

• In vitro evaluation of transdermal therapeutic systems (TTS) commonly uses flow-through diffusion cells.
• Apparent flux measurements in these systems do not accurately reflect intrinsic drug permeation through skin.
• Experimental parameters in flow-through systems can significantly alter flux profiles and lag times.

Purpose of the Study:

• To derive a transfer function that quantifies the impact of flow-through system parameters on flux measurements.
• To enable the calculation of true intrinsic permeation flux from apparent flux data.
• To obtain accurate permeant flux profiles for TTS development, free from experimental artifacts.

Main Methods:

• Development of a mathematical transfer function to model flow-through diffusion cell parameters.
• Utilizing the derived transfer function to correct apparent flux data.
• Experimental validation of the transfer function with flow-through system parameters.

Main Results:

• A transfer function was successfully derived, accurately describing the influence of system parameters on flux.
• Intrinsic flux values were calculated from apparent flux data, correcting for experimental modifications.
• The methodology allows for the determination of permeant flux profiles independent of flow-through cell artifacts.

Conclusions:

• The developed transfer function is crucial for accurate in vitro assessment of transdermal drug permeation.
• This approach enhances the reliability of data generated from flow-through diffusion cells for TTS research.
• Accurate intrinsic flux determination is vital for the successful design and optimization of transdermal therapeutic systems.