Effect of treatment duration on iontophoretic efficacy

A monophasic rectangular pulsed constant-current iontophoretic device was designed, built, and tested on acutely induced hypertensive New Zealand white rabbits. Pressure was monitored during iontophoretic transdermal administration of the antihypertensive drug, captopril. The effect of duration of iontophoretic treatment on the pressure response was investigated. Our results show that significant loading of the drug within the stratum corneum reservoirs occurred only after 20 minutes of stimulation. With this pooling effect, drug levels within the circulation could remain at therapeutic levels to keep pressures low long after the stimulation was removed.