Noninvasive measurement of transdermal drug delivery by impedance spectroscopy.
The effectiveness in transdermal delivery of skin permeation strategies (e.g., chemical enhancers, vesicular carrier systems, sonophoresis, iontophoresis, and electroporation) is poorly investigated outside of laboratory. In therapeutic application, the lack of recognized techniques for measuring the actually-released drug affects the scientific concept itself of dosage for topically- and transdermally-delivered drugs. Here we prove the suitability of impedance measurement for assessing the amount of drug penetrated into the skin after transdermal delivery. In particular, the measured amount of drug depends linearly on the impedance magnitude variation normalized to the pre-treated value. Three experimental campaigns, based on the electrical analysis of the biological tissue behavior due to the drug delivery, are reported: (i) laboratory emulation on eggplants, (ii) ex-vivo tests on pig ears, and finally (iii) in-vivo tests on human volunteers. Results point out that the amount of delivered drug can be assessed by reasonable metrological performance through a unique measurement of the impedance magnitude at one single frequency. In particular, in-vivo results point out sensitivity of 23 ml-1, repeatability of 0.3%, non-linearity of 3.3%, and accuracy of 5.7%. Finally, the measurement resolution of 0.20 ml is compatible with clinical administration standards.
University of Naples Federico II, Department of Electrical Engineering and Information Technology, Via Claudio21, 80125 Naples, Italy.
Pasquale
P
Arpaia
University of Naples Federico II, Department of Electrical Engineering and Information Technology, Via Claudio21, 80125 Naples, Italy.
Umberto
U
Cesaro
CRdC Tecnologie Scarl, Via Nuova Agnano, 11-80125 Naples, Italy.
Nicola
N
Moccaldi
D000279:Administration, Cutaneous; D000328:Adult; D000818:Animals; D058266:Dielectric Spectroscopy / Q000379:methods*; D004423:Ear; D004566:Electrodes; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D000071228:Polyelectrolytes / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption / Q000502:physiology*; D032323:Solanum melongena / Q000378:metabolism; D013552:Swine
D000071228:Polyelectrolytes; D006820:Hyaluronic Acid