Transdermal drug delivery system: Active method for enhancing and controlling lidocaine hydrochloride diffusion

The objective of this study is to determine the effect of iontophoresis on the transport of lidocaine hydrochloride (2%, w/w) across ear pig skin. Our project consists of the development of a transdermal drug delivery system (TDDS). The system is designed as a reusable electronic patch where micropump, reservoir, sensors and Bluetooth communication are integrated. Therefore, quantify the iontophoretic diffusion and investigate the effect of different current densities in enhancing and controlling drug delivery is a primordial step. In vitro iontophoresis experiments were conducted using Franz diffusion cells. Iontophoresis was applied for 30 minutes at current density of 0.25, 0.5 and 0.75 mA/cm
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. Samples (1 mL) were withdrawn every 30 minutes from the receptor compartment and replaced with fresh buffer and then analyzed using High Performance Liquid Chromatography (HPLC). The amount of lidocaine HCl delivered was 247 ± 19, 199 ± 14 and 115 ± 7.11 μg/cm
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for 0.75, 0.5 and 0.25 mA/cm
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respectively and 25.6 ± 3.02 μg/cm
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for passive diffusion. The amount is influenced by current density, and could be therefore enhanced, predicted and controlled by those parameters.