In vitro percutaneous absorption evaluation of phenobarbital through hairless mouse, adult and premature human skin

In vitro phenobarbital flux through newborn (preterm and full-term) infant, hairless mouse and adult human skin was determined using both Franz cells and flow-through diffusion cells. The phenobarbital flux value through preterm infant skin was significantly higher than that obtained through full-term infant skin which, in turn, was close to that measured for adult human skin. No significant difference was observed between phenobarbital flux values through preterm infant skin and hairless mouse skin using flow-through diffusion cells: this result suggests that hairless mouse skin can be successfully used as a model to study in vitro percutaneous absorption of phenobarbital through preterm infant skin. Phenobarbital flux through preterm infant skin was affected by the gestational age since flux decreased as the gestational age increased and from 37 weeks gestation onward (full-term infants) flux values were similar to those determined for adult human skin. Since by using the flux value from the in vitro experiments on preterm infant skin a steady state plasma concentration close to the therapeutic level can be predicted, phenobarbital transdermal delivery in preterm infants could be regarded as feasible.