Effect of microporation on passive and iontophoretic delivery of diclofenac sodium

AbstractSkin pretreatment with a microneedle roller (microporation (MP)) appears a simple and inexpensive technique to increase transdermal delivery of topically applied drug products. This study investigates the effect of MP on the passive and iontophoretic delivery of diclofenac (DCF) by quantifying dermis and plasma levels of DCF in a rabbit model. New Zealand albino female rabbits received either: (i) a topical application of 4 g of Voltaren® 1% gel with or without pretreatment with a microroller (0.5 mm needle length; density 23 microneedles per cm2 area) or (ii) a DCF solution (40 mg/2.5 mL) via iontophoresis (IOMED transQE medium size patch), with or without microroller pretreatment. A 300 µA/cm2 cathodic current was applied for 20 min for a total of 80 mA. DCF concentrations were monitored in dermis with microdialysis sampling every 20 min for 5 h. Plasma samples were collected over the same period. In the passive delivery studies, microroller pretreatment increased Cmax by 1.5- and 2.0-fold in sk...