Electromotive administration of oxybutynin into the human bladder wall.

Abstract

To compare concentrations of oxybutynin in the human bladder wall after either passive delivery (PD) or electromotive administration (EMDA). Tissue sections of human bladder were inserted into a diffusion cell with urothelium exposed to the donor compartment containing oxybutynin (4.5 mg. in 100 ml. NaCl 0.45%) and an anode. Twelve paired experiments, "current 5 mA/no current", were conducted over 15 minutes. Oxybutynin tissue contents were measured and tissue viability, morphology and oxybutynin stability were assessed. Mean oxybutynin tissue concentrations were 3.84 micrograms./gm. in samples exposed to EMDA and 0.87 microgram./gm. in samples exposed to PD (p = 0.0006). The mean coefficients of variation were 57.85% in EMDA experiments and 89.78% in PD experiments. Tissues were viable and undamaged histologically and no oxybutynin structural modification was observed. EMDA enhances oxybutynin administration into viable bladder wall and reduces the variability in drug delivery rate.