Determination of mirodenafil and sildenafil in the plasma and corpus cavernous of SD male rats

The purpose of the present study was to determine sildenafil and a novel PDE-5 inhibitor, mirodenafil in the plasma and corpus cavernosum tissue of rats to compare their pharmacokinetic properties. The concentrations of mirodenafil and sildenafil in the rat plasma and corpus cavernosum tissue samples were analyzed using LC–MS/MS after a single oral administration at a dose of 40 mg/kg to rats. Although the Tmax, Tλ1/2 and MRT were not different between mirodenafil and sildenafil, the Cmax and AUC of mirodenafil were significantly higher than those of sildenafil in the plasma and corpus cavernosum tissue. Consequently mirodenafil remained longer than sildenafil in the plasma and tissue. This may provide pharmacokinetic evidence for assessment of the in vivo efficacy of mirodenafil and sildenafil.