Scientists secure funding to develop better methods for evaluation of topically applied drugs

A team of leading scientists from Bath University UK, the UK's National Physical Laboratory (NPL), and the Colorado School of Mines USA has secured funding from the US Food and Drug Administration (FDA) to develop better methods to assess the performance of topically applied drug products. These include creams and lotions for conditions like acne, psoriasis and eczema.

Accurate, reproducible and non-invasive methods are necessary to effectively analyze topical drug delivery. Current approaches (such as skin penetration tests, microdialysis and tape-stripping) can be time-consuming, expensive and technically challenging. Therefore, both industry and the regulatory authorities are motivated to identify standardized, reproducible, and validated protocols that accurately reflect the quality and performance of these drug products.

The project brings experts in advanced Raman spectroscopy and mass spectrometry imaging at NPL together with world leaders in topical drug delivery and formulation, dermal pharmacokinetic modelling and skin bioavailability at Bath University and Colorado School of Mines to address this challenge.

NPL contributes a specialized imaging technique – stimulated Raman spectroscopy – a non-invasive, accurate and sensitive tool to determine the rate and extent at which a topically administered drug becomes available at its site of action within the skin. The method enables analysis of the drug and quantification of its transport across the skin in real time. Alongside this, NPL’s mass spectrometry imaging expertise enables the results from the Raman experiments to be rigorously calibrated and validated.

A key challenge that the team aim to overcome is to distinguish the signal from the drug in the skin from the background signals originating from the skin itself.

These powerful imaging techniques will provide complementary information to allow a detailed analysis of drugs that are applied to the skin. This will lead to new and accurate methods for the measurement and standardization of topically applied drugs and, ultimately, the development and broader accessibility of more effective products.

Professor Richard Guy at Bath University explained:

The project aims to develop and validate a novel and noninvasive application of Raman and mass spectroscopic techniques to evaluate the bioavailability of a topically applied drug in the skin. The successful attainment of this objective will advance regulatory science and accelerate the route-to-market of new drug products.”

Dr Natalie Belsey, Senior Research Scientist at the National Physical Laboratory (NPL) said:

Coherent Raman-based optical imaging methods enable non-invasive, real-time chemical measurements. The mass spectrometry imaging capability at NPL brings major benefits of sensitivity and chemical specificity. In combination, these complementary spectroscopic imaging methods offer a powerful technology tool kit with which to asses and enhance the performance of formulated drug products.”