Rapid imaging method shows how medicine moves beneath the skin

Researchers from The Hebrew University of Jerusalem have developed a rapid imaging technique that allows them to visualise, within minutes, how drugs move through and settle in the skin’s layers. Tested on antifungal treatments, it is said to offer a faster, more precise way to design safer and more effective topical and transdermal therapies.

Delivering drugs through the skin requires remarkable precision. Some treatments must reach deep into the dermis to enter the bloodstream, while others, like antifungal creams or acne treatments, need to remain close to the surface, targeting a specific sublayer of the epidermis.

But measuring exactly how far a compound travels beneath the skin can be a tedious process, often taking days and relying on indirect fluorescent methods. Dr Katy Margulis and her team have now developed a new mass spectrometry imaging (MSI) method combined with an automated computational tool that can analyse drug distribution within a skin sample in under 10 minutes.

Described in the journal Small Science, the tool computationally segments the tissue into distinct layers and maps where the active ingredient lands, providing a clear visual of drug permeation depth without any need for chemical labelling. While traditional methods for assessing drug permeation require labour-intensive image analysis, the automated clustering tool developed by the researchers reduces the process to minutes, enabling rapid testing of multiple formulations and facilitating time-sensitive studies.

“This approach gives us a clear, label-free snapshot of where a drug actually goes once applied to the skin,” Margulis said. “It allows researchers and developers to optimise delivery systems quickly and with much greater accuracy.”

To test the method, the team examined three nanoscale drug delivery systems for antifungal medication terbinafine, each designed to reach a different depth within the skin. Using their new imaging workflow, they compared how effectively each system delivered terbinafine through human and animal skin and discovered striking differences between the systems in depth and extent of drug permeation as well as the drug’s skin distribution patterns. This can enable precise tailoring of the delivery system to both the drug and the skin condition.

Beyond antifungal therapy, the new method could improve the safety and precision of corticosteroids, retinoids and other topical drugs, as well as enhance cosmetic and transdermal treatments tailored to specific skin conditions.

The innovation also supports kinetic research, allowing scientists to track how fast and how deep a drug moves through the skin. As explained by Margulis, “We can now monitor drug absorption in near real time. This opens the door to time-sensitive treatments and more precise dosing.”

The study therefore not only enhances pharmaceutical development but also advances the broader goal of precision medicine, which aims at tailoring treatments based on individual biology. By making it possible to map drug distribution rapidly and accurately, the new method could eventually support personalised skincare or medical creams adjusted for a patient’s specific skin type or condition.

“This tool allows for smarter, safer and more efficient formulation testing,” Margulis said. “Ultimately, it helps bring better products to patients faster.”

Image credit: iStock.com/andegro4ka