Non-invasive skin sampling detects systemically administered drugs in humans

Area of Science:

• Pharmacology
• Analytical Chemistry
• Biomedical Science

Background:

• Traditional clinical testing involves invasive procedures like blood draws and biopsies.
• Developing minimally invasive sampling methods is crucial for improving patient experience.
• Skin swabbing represents one of the least invasive sample collection techniques available.

Purpose of the Study:

• To evaluate the feasibility of using skin swabs combined with untargeted mass spectrometry for non-invasive monitoring of orally administered drugs.
• To investigate the pharmacokinetics and metabolism of diphenhydramine in healthy volunteers via skin sampling.
• To demonstrate that systemically administered drugs and their metabolites can be detected on the skin surface.

Main Methods:

• Healthy volunteers (n=10) received an oral dose of diphenhydramine.
• Blood samples were collected, along with swabs from three distinct skin regions over 24 hours.
• Untargeted mass spectrometry (metabolomics) was employed to analyze collected samples.

Main Results:

• Diphenhydramine and its metabolites were detected on the skin surface.
• Detection on the skin occurred after peak plasma levels were observed.
• The presence and levels of the drug and metabolites varied by skin location and compound.

Conclusions:

• Non-invasive skin swabs coupled with untargeted mass spectrometry can detect systemically administered drugs.
• Both the parent drug (diphenhydramine) and its metabolites can be qualitatively measured from skin swabs.
• The findings support the potential for a novel, patient-friendly approach to drug monitoring, although the pathway to the skin surface requires further investigation.