A proof-of-concept study utilising 2D NMR spectrometry for in situ characterisation and quantitation of key biomarkers and actives in tape stripped ex vivo human skin

Cameron Robertson,Nidhin Raj,Robert Lucas,Tomris Coban,Adam Le Gresley

doi:10.1016/j.talanta.2021.122980

Cameron Robertson, Nidhin Raj + Show 3 more

Open Access

https://doi.org/10.1016/j.talanta.2021.122980

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Journal: Talanta	Publication Date: Oct 20, 2021
Citations: 1	License type: cc-by

Affiliation: Kingston University, GlaxoSmithKline (United Kingdom)

Abstract

The development of a semi-automated and rapid analytical technique for dermatological analysis has become a key aim of many medical and commercial entities through greater awareness of people to skin health and its importance in the 21st century. We present a proof-of-concept methodology demonstrating the use of validated non-destructive, in-situ (Nuclear Magnetic Resonance Spectroscopy) NMR techniques for characterisation and quantitation of (Natural Moisturising Factor) NMF compounds and actives from topical formulations. This quantitation is crucial for appropriate diagnosis of atopic dermatitis severity due to its association with reduced NMF abundance. This study is the first to combine diffusion NMR, semi-automated quantitation and ex-vivo skin samples to measure NMF and permeation of actives. We have shown that diffusion NMR allows for resolution between formulation components through determination of self-diffusion coefficients. We also demonstrate how the metabolomics software chenomxtm can be used to identify and quantitate individual NMF components. We show comparable results to previous literature on NMF layers in the skin, alongside reinforcing findings on permeation enhancers and heat effects on transdermal delivery of actives and formulation components. The presented methodology has shown great potential as an effective non-destructive, fast and versatile technique for dermatological analysis of physiology and actives, with future hardware and software developments in NMR making the future of dermatological analysis via NMR very promising.

Highlights

It has been demonstrated, through tape stripping methods, that the Stratum corneum (SC) varies between areas of the body, for example the cheek SC is less able to retain water
Skin samples were subsequently separated into 6 groups and treated respectively; Native skin with no topical treatment applied (Ctrl), Physiogel AI lipid formulation (AI), Physiogel formulaton (AI), BlueWater formulation vehicle (V), BlueWater formulation (BW) and BlueWater formulation heat treated at 70Co (BW70)
One limitation found during this assignment was the overlap of fatty acid peaks from the skin’s intercellular lipid matrix and those added in treatment groups

Summary

Introduction

Through tape stripping methods, that the Stratum corneum (SC) varies between areas of the body, for example the cheek SC is less able to retain water. Elucidation of these differences was carried out by analysis of SC protein concentrations, enzyme activities and TEWL measurements [1]. Further studies measuring the SC proteins have shown clear variation in the biochemistry of individuals who suffer from sensitive skin [2]. Natural moisturising factors (NMF) have largely been investigated for their role in retaining moisture in the skin and maintenance of the Stratum corneum surface. Regional and temporal differences in NMF, alongside protease activities, have been suggested as a prediction tool for Atopic dermatitis in early childhood [3]

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