Detection of follicular transport of lidocaine and metabolism in adipose tissue in pig ear skin by DESI mass spectrometry imaging
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Desorption electrospray ionization (DESI) mass spectrometry imaging is demonstrated as a detection technique for penetration experiments of drugs in skin. Lidocaine ointment was used as the model compound in ex vivo experiments with whole pig ears as the skin model. Follicular transport of lidocaine into the deeper skin layers is demonstrated for the first time. Furthermore, metabolism of lidocaine to 3-OH-lidocaine was observed in subcutaneous tissue as well as in lobules of white adipose tissue surrounding the hair follicles. These results suggest that it is advantageous to use full thickness skin, including subcutaneous tissue, for skin metabolism studies.
KeywordsDESI Lidocaine Mass spectrometry imaging Pig ear skin Drugs Topical
The authors thank Kristian Moller (LEO Pharma A/S) for useful discussions on skin sections. Furthermore, we thank André Eriksson and Karsten Petersson for providing the pig ears and Louise Bastholm-Jensen for an introduction to penetration experiments (all from LEO Pharma A/S). Support from the Carlsberg Foundation, The Danish Council for Independent Research|Natural Sciences and LEO Pharma A/S is gratefully acknowledged.
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