Tel: +44 (0) 1225 383969
Dr Begoña Delgado-Charro
Transdermal Drug Delivery by Iontophoresis
Iontophoresis - the use of an electrical potential gradient to promote the transdermal penetration of charged molecules - is perhaps the most powerful, yet relatively non-invasive approach available at present to enhance molecular permeability across intact skin.
Present work focuses on better understanding the complex dependence of transport number upon the concentration and mobility of all the ions present at both sides of the skin, and the physicochemical properties which determine iontophoretic drug fluxes. A project funded by the Parkinson's Disease Society, UK screened the feasibility of a transdermal iontophoretic administration of anti-Parkinsonian drugs. A project funded by the MRC in collaboration with Dr S. Husbands, Dr C. Bailey and Prof. R. Guy currently looks into the development of an iontophoretic patch to treat drug addiction.
Non-Invasive Drug Monitoring, Clinical Chemistry and Pharmacokinetics
Non-invasive sampling methodologies provide more information as sampling can be performed more frequently, they decreased pain and discomfort, risk of infection, and offer potential for home-monitoring, etc.
We currently investigate the use of "reverse iontophoresis" as a non-invasive approach for therapeutic drug monitoring, clinical chemistry, assessment of chemical exposure and skin health, and pharmacokinetic profiling via the skin. Complementary work uses tape-stripping to interrogate the Stratum Corneum and collaboration with Dr White (Mathematical Sciences) aims to model how chemical accumulate into the skin.
Nail Drug Delivery
The current treatment of nail diseases such as psoriasis and onychomycosis is far from optimal. Unfortunately, the available topical therapies are not very efficient. We use iontophoresis as a tool to enhance trans-ungual transport of antifungal drugs into and across the nail plate and investigate other formulation alternatives.
Djabri, A., van’t Hoff, W., Brock, P., Wong, I. C.K., Guy, R. H. and Delgado-Charro, B., 2015. Iontophoretic transdermal sampling of iohexol as a noninvasive tool to assess glomerular filtration rate. Pharmaceutical Journal, 32 (2), pp. 590-603.
Delgado-Charro, M. B. and Guy, R. H., 2014. Effective use of transdermal drug delivery in children. Advanced Drug Delivery Reviews, 73, pp. 63-82.
Güngör, S., Delgado-Charro, M. B., Masini-Etévé, V., Potts, R. O. and Guy, R. H., 2013. Transdermal flux predictions for selected selective oestrogen receptor modulators (SERMs):Comparison with experimental results. Journal of Controlled Release, 172 (3), pp. 601-606.
Delgado-Charro, M. B., 2013. Richard Guy and his collaborators : 'crackling' the skin code. Skin Pharmacology and Physiology, 26 (4-6), pp. 302-312.
Benzeval, I., Bowen, C. R., Guy, R. H. and Delgado-Charro, M. B., 2013. Effects of iontophoresis, hydration, and permeation enhancers on human nail plate: Infrared and impedance spectroscopy assessment. Pharmaceutical Research, 30 (6), pp. 1652-1662.
Gelfuso, G. M., Gratieri, T., Delgado-Charro, M. B., Guy, R. H. and Vianna Lopez, R. F., 2013. Iontophoresis-targeted, follicular delivery of minoxidil sulfate for the treatment of alopecia. Journal of Pharmaceutical Sciences, 102 (5), pp. 1488-1494.
Nogueiras-Nieto, L., Delgado-Charro, M. B. and Otero-Espinar, F.J., 2013. Thermogelling hydrogels of cyclodextrin/poloxamer polypseudorotaxanes as aqueous-based nail lacquers: application to the delivery of triamcinolone acetonide and ciclopirox olamine. European Journal of Pharmaceutics and Biopharmaceutics, 83 (3), pp. 370-377.
Dutet, J. and Delgado-Charro, M.B., 2012. Assessment of iontophoretic and passive ungual penetration by laser scanning confocal microscopy. Pharmaceutical Research, 29 (12), pp. 3464-3474.
Djabri, A., Guy, R. H. and Delgado-Charro, M. B., 2012. Transdermal iontophoresis of ranitidine: An opportunity in paediatric drug therapy. International Journal of Pharmaceutics, 435 (1), pp. 27-32.
Campbell, C. S. J., Contreras-Rojas, L. R., Delgado-Charro, B. and Guy, R. H., 2012. Objective assessment of nanoparticle disposition in mammalian skin after topical exposure. Journal of Controlled Release, 162 (1), pp. 201-207.
Cabana Montenegro, S., Delgado-Charro, M. B. and Fotaki, N., 2012. Development and evaluation of age appropriate pellet formulations for an antiepileptic drug. In: 4th Conference of the European Paediatric Formulation Initiative (EuPFI) 2012, 2012-09-19 - 2012-09-20, Prague.
Djabri, A., Guy, R. H. and Delgado-Charro, M. B., 2012. Passive and iontophoretic transdermal delivery of phenobarbital: implications in paediatric therapy. International Journal of Pharmaceutics, 435 (1), pp. 76-82.
Nogueiras-Nieto, L., Gómez-Amoza, J. L., Delgado-Charro, M. B. and Otero-Espinar, F. J., 2011. Hydration and N-acetyl-l-cysteine alter the microstructure of human nail and bovine hoof: implications for drug delivery. Journal of Controlled Release, 156 (3), pp. 337-344.
Paulley, Y., Delgado-Charro, M. B. and White, K. A. J., 2011. Modelling the formation of a lithium reservoir in the skin; an alternative non-invasive strategy for drug sampling? Therapeutic Drug Monitoring, 33 (4), p. 556.
Delgado-Charro, M. B., 2011. Sampling substrates by skin permeabilization. In: Murthy, S. N., ed. Dermatokinetics of Therapeutic Agents. Boca Raton: Taylor and Francis, pp. 149-174.
Taverner, A., Cordery, S., Husbands, S. M., Guy, R. H., Delgado-Charro, B. M. and Bailey, C. P., 2011. Transdermal delivery of a buprenorphine/naltrexone combination for the treatment of polydrug abuse. Pharmacological Reports, 63 (1), p. 257.
Paulley, Y., Delgado-Charro, M. B. and White, K. A. J., 2010. Modelling formation of a drug reservoir in the stratum corneum and its impact on drug monitoring using reverse iontophoresis. Computational and Mathematical Methods in Medicine, 11 (4), pp. 353-368.
Güngör, S., Delgado-Charro, M. B., Ruiz-Perez, B., Schubert, W., Isom, P., Moslem, P., Patane, M. A. and Guy, R. H., 2010. Trans-scleral iontophoretic delivery of low molecular weight therapeutics. Journal of Controlled Release, 147 (2), pp. 225-231.
Sylvestre, J. P., Bouissou, C., Guy, R. H. and Delgado-Charro, M. B., 2010. Extraction and quantification of amino acids in human stratum corneum in vivo. British Journal of Dermatology, 163 (3), pp. 458-465.
Dutet, J. and Delgado-Charro, M. B., 2010. Transungual iontophoresis of lithium and sodium: effect of pH and co-ion competition on cationic transport numbers. Journal of Controlled Release, 144 (2), pp. 168-174.
Dutet, J. and Delgado-Charro, M. B., 2010. Electroosmotic transport of mannitol across human nail during constant current iontophoresis. Journal of Pharmacy and Pharmacology, 62 (6), pp. 721-729.
Dutet, J. and Delgado-Charro, M. B., 2009. In vivo transungual iontophoresis: effect of DC current application on ionic transport and on transonychial water loss. Journal of Controlled Release, 140 (2), pp. 117-125.
Bouissou, C. C., Sylvestre, J.-P., Guy, R. H. and Delgado-Charro, M. B., 2009. Reverse iontophoresis of amino acids: identification and separation of stratum corneum and subdermal sources in vitro. Pharmaceutical Research, 26 (12), pp. 2630-2638.
Nicoli, S., Bunge, A. L., Delgado-Charro, M. B. and Guy, R. H., 2009. Dermatopharmacokinetics: factors influencing drug clearance from the stratum corneum. Pharmaceutical Research, 26 (4), pp. 865-871.
Delgado-Charro, M. B., 2009. Recent advances on transdermal iontophoretic drug delivery and non-invasive sampling. Journal of Drug Delivery Science and Technology, 19 (2), pp. 75-88.
Sieg, A., Jeanneret, F., Fathi, M., Hochstrasser, D., Rudaz, S., Veuthey, J. L., Guy, R. H. and Delgado-Charro, M. B., 2009. Extraction of amino acids by reverse iontophoresis in vivo. European Journal of Pharmaceutics and Biopharmaceutics, 72 (1), pp. 226-231.
Sylvestre, J., Diaz-Marin, C., Delgado-Charro, M. and Guy, R., 2008. Iontophoresis of dexamethasone phosphate: Competition with chloride ions. Journal of Controlled Release, 131 (1), pp. 41-46.
Sylvestre, J. -P., Guy, R. H. and Delgado-Charro, M. B., 2008. In vitro optimization of Dexamethasone Phosphate delivery by iontophoresis. Physical Therapy, 88 (10), pp. 1177-1185.
Trichard, L., Delgado-Charro, M. B., Guy, R. H., Fattal, E. and Bochot, A., 2008. Novel beads made of alpha-cyclodextrin and oil for topical delivery of a lipophilic drug. Pharmaceutical Research, 25 (2), pp. 435-440.
Sieg, A., Jeanneret, F., Fathi, M., Hochstrasser, D., Rudaz, S., Veuthey, J. L., Guy, R. H. and Delgado-Charro, M. B., 2008. Extraction of amino acids by reverse iontophoresis: Simulation of therapeutic monitoring in vitro. European Journal of Pharmaceutics and Biopharmaceutics, 70 (3), pp. 908-913.
Russell, L., Wiedersberg, S. and Delgado-Charro, M. B., 2008. The determination of stratum corneum thickness An alternative approach. European Journal of Pharmaceutics and Biopharmaceutics, 69 (3), pp. 861-870.