My research focuses on transdermal and topical drug delivery, the development of optimized methods to treat nail diseases, such as onychomycosis and psoriasis, non-invasive sampling for drug monitoring and pharmacokinetics, and mathematical modelling to predict the accumulation of chemicals in the skin and to predict skin absorption.
My work on drug delivery, prediction of skin absorption, bioequivalence of topical drug products and non-invasive sampling has been funded by the Leo Foundation, the Parkinson’s Disease Society UK, the UK Medical Research Council, the Swiss National Foundation, the NHS-NIC, the US-FDA and several pharmaceutical companies.

Transdermal and topical drug delivery. Representative work:
a. Paterson et al., Is the skin absorption of hydrocortisone modified by the variability in dosing topical products? Pharmaceutics 10 (2018) 9 doi:10.3390/pharmaceutics10010009
b. Gainza et al., Development and in vitro evaluation of lipid nanoparticle-based dressings for topical treatment of chronic wounds. Int. J. Pharm., 490 (2015) 404-411.
c. Güngör et al., Transdermal flux predictions for selective oestrogen receptor modulators (SERMs): Comparison with experimental results. J. Control. Release. 172 (2013) 601-606.

Formulation of colloidal topical vehicles. Representative work:
a. Flores et al., Tioconazole-loaded cationic polymeric nanocapsules as ungual drug delivery systems. Int. J. Pharm. 535 (2018) 237-244.
b. Chiu et al., Drug delivery into microneedle-porated nails from nanoparticle reservoirs. J Control. Release, 20, (2015) 98-106.
c. Trichard et al., Novel beads made of alpha-cyclodextrin and oil for topical delivery of a lipophilic drug, Pharm Res. 25 (2008) 435-40.
d. Campbell et al., Objective assessment of nanoparticle disposition in mammalian skin after topical exposure. J. Control. Release. 162 (2012) 201-207.

In vitro-in vivo correlations and assessment of topical bioavailability and bioequivalence. Representative work:
a. Pedon de Araujo et al., Topical bio(in)equivalence of metronidazole formulations in vivo. Int. J. Pharm. 541 (2018) 167-172.
b. Cordery et al., Topical bioavailability of diclofenac from locally-acting, dermatological formulations. Int. J. Pharm. 529 (2017) 55-64.
c. Bastos Leal et al., Bioequivalence methodologies for topical drug products: in vitro and ex vivo studies with a corticosteroid and an anti-fungal drug. Pharm Res. 34 (2017) 730-737.
d. Russell et al., The determination of stratum corneum thickness – an alternative approach. Eur. J. Pharm. Biopharm., 69 (2008) 861-870.

Mathematical modelling of chemical accumulation into the skin, skin absorption and skin sampling. Representative work:
a. Jones et al., A mechanistic approach to modelling the formation of a drug reservoir in the skin. Mathematical Biosciences (2016) 36-45.
b. Paulley et al., Modelling formation of a drug reservoir in the stratum corneum and its impact on drug monitoring using reverse iontophoresis. Comput. Math. Methods M. 11(2010) 353-368.

The mechanism of transport underlying iontophoretic transport: transport numbers (competition of co- and counter ions) and contribution of convective solvent flow to transdermal flux. Representative work:
a. Dutet et al., Transungual iontophoresis of lithium and sodium: Effect of pH and co-ion competition on cationic transport numbers. J. Control Release. 144 (2010) 168–174.
b. Mudry et al., Prediction of iontophoretic transport across the skin. J Control. Release. 111 (2006) 362-367.
c. Mudry et al.,Transport numbers in transdermal iontophoresis. Biophysical J. 90 (2006) 2822-2830.
d. Mudry et al., Electromigration of ions across the skin: determination and prediction of transport numbers. J. Pharm. Sci. 95 (2006) 561-569.

Drug delivery to the nail and its enhancement. Representative work:
a. Cutrín Gómez et al., Microstructural alterations in the onychomycotic and psoriatic nail: relevance in drug delivery Eur J. Pharm. Biopharm. 128 (2018) 48-56.
b. Dutet et al., Assessment of iontophoretic and passive ungual penetration by laser scanning confocal microscopy. Pharm. Res. 29 (2012) 3464-3474.
c. Dutet et al., In vivo transungual iontophoresis: Effect of DC current application on ionic transport and on transonychial water loss. J. Control. Release. 140 (2009)117-25.

Effects of chemical enhancers and solvents on biological membranes. Representative work:
a. Chiu et al., Molecular diffusion in the human nail measured by stimulated Raman scattering microscopy. Proc. Natl. Acad. Sci., USA, 112 (2015) 7725–7730.
b. Benzeval et al., Effects of iontophoresis, hydration and permeation enhancers on human nail plate: infrared and impedance spectroscopy assessment. Pharm. Res, 30 (2013) 1652-1662.
c. Nogueiras-Nieto et al., Hydration and n-acetyl-L-cysteine alter the microstructure of human nail and bovine hoof: Implications for drug delivery. J. Control Release, 156 (2011) 337-344.
d. Nicoli et al., Dermatopharmacokinetics: factors influencing drug clearance from the stratum corneum. Pharm. Res. 26 (2009) 865-871.

Non-invasive skin sampling using iontophoresis and other extraction methods for therapeutic drug monitoring, clinical chemistry and skin health applications. Representative work:
a. du Toit, et al., Generating power from transdermal extracts using a multi-electrode miniature enzymatic fuel cell. Biosensors and Bioelectronics, 78 (2016) 411–417.
b. Sylvestre et al., Extraction and quantification of amino acids in human stratum corneum in vivo. Br J Dermatol. 163 (2010) 458-465
c. Leboulanger et al., Lithium monitoring by reverse iontophoresis in vivo. Clin. Chem. 50 (2004) 2091-2100.
d. Sieg et al., Non-invasive glucose monitoring by reverse iontophoresis in vivo: application of the internal standard concept. Clin. Chem. 50 (2004) 1383-1390.

Interest in paediatric drug delivery and non-invasive sampling kinetics. Representative work:
a. Djabri et al., Iontophoretic transdermal sampling of iohexol as a non-invasive tool to assess glomerular filtration rate. Pharm Res 32 (2015) 590-603.
b. Djabri et al., Iontophoretic delivery of ranitidine: an opportunity in paediatric drug therapy. International Journal of Pharmaceutics. 435 (2012) 27-62
c. Djabri et al., Passive and iontophoretic transdermal delivery of phenobarbital: implications in paediatric therapy. Int. J. Pharm. 435 (2012) 76-82.