Comparison of Membrane Depth Determination Techniques for Active Ingredient Skin Penetration Studies Using...

Area of Science:

• Dermal drug delivery research
• Transdermal therapeutic systems
• Skin penetration science

Background:

• The skin acts as a barrier, presenting challenges for topical active ingredient delivery.
• Efficacy of topical treatments depends on ingredient release into dermal and epidermal tissues.

Purpose of the Study:

• To investigate how physicochemical properties influence skin penetration depth of active ingredients.
• To determine the impact of lipophilicity on dermal penetration.

Main Methods:

• Utilized a microdialysis (MD) setup in porcine skin with superficial and deep membranes.
• Employed histological sectioning, microscopy, ultrasound, and computed tomography for precise MD membrane depth determination.
• Compared penetration of hydrophilic caffeine and lipophilic LIP1 (identical molecular weight) to assess lipophilicity effects.

Main Results:

• Accurate determination of MD membrane depth is critical for percutaneous penetration studies.
• Lipophilicity influences active ingredient penetration depth and concentration at the target site.
• Caffeine demonstrated greater transdermal penetration than LIP1 in the hydrophilic dermal environment.

Conclusions:

• Precise microdialysis (MD) localization within the dermis is crucial.
• Physicochemical properties, particularly lipophilicity, significantly affect active ingredient penetration rates.
• Findings provide a basis for developing enhanced transdermal delivery systems.