Related Experiment Video
Updated: Nov 4, 2025

Author Spotlight: A Pharmacodissection Approach to Uncover Mechanisms in Cardiovascular Disease Risk Populations
Published on: July 21, 2023
Comparison of Membrane Depth Determination Techniques for Active Ingredient Skin Penetration Studies Using
Markus Lubda1,2, Maximilian Zander1,2, Andrew Salazar1
1Cosmetic Functionals, Merck KGaA, Darmstadt, Germany.
Introduction:
The skin is a major physical barrier to the environment, and thus, percutaneous delivery of active ingredients to the dermal target site faces a unique set of hurdles. The efficacy of these active ingredients is governed by their release into the underlying epidermal and dermal tissue, especially when administered topically.
Objective:
The aim of this study was to understand if different physicochemical properties influence the skin penetration of active ingredients and the depth to which they penetrate into the dermis.
Methods:
A microdialysis (MD) setup was used to compare the percutaneous penetration in superficial and deep implanted MD membranes in porcine skin. The precise MD membrane depth was determined using histological sectioning paired with microscopy, ultrasound, and a novel computed tomographic approach.
Results:
In study A, the measured depth of the superficial and deep implanted MD membranes was compared using histological sectioning, ultrasound, and computed tomography. Experimental determination of the depth up to which penetration occurs was found to be crucial to percutaneous penetration studies. In study B, the lipophilic differences of the active ingredients and its influences on the penetration was tested using hydrophilic caffeine and lipophilic LIP1 as model compounds, which have an identical molecular weight with different lipophilic characteristics. It is assumed that the lipophilic characteristics of active ingredients influence their penetration and thus governs the concentration of these molecules reaching their target site.
Conclusion:
The transdermal penetration of caffeine was found to exceed that of LIP1 through the hydrophilic environment of the dermis. Thus, the findings of this study show that the precise MD dermis localization and the physicochemical properties, such as lipophilicity, influence the penetration rate of active ingredients and lay the foundation for creating optimized transdermal delivery systems.
More Related Videos
10:33A Method for Determination and Simulation of Permeability and Diffusion in a 3D Tissue Model in a Membrane Insert System for Multi-well Plates
Published on: February 23, 2018
11:07Visualizing and Quantifying Pharmaceutical Compounds within Skin using Coherent Raman Scattering Imaging
Published on: November 24, 2021
Related Concept Videos
Methods for Studying Drug Absorption: In vitro
The diffusion cell method uses a two-compartment cell, including a donor compartment with the drug solution, which simulates the environment where the drug is applied, and a receptor compartment with a buffer solution, which simulates the environment...
Dialysis
In Vitro Drug Dissolution: Compendial Testing Models II
In Vitro Drug Dissolution: Alternative Methods
Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...
Drug Absorption Mechanism: Passive Membrane Transport