Determination of in vivo concentration-time profiles of chlorhexidine and noxythiolin bladder irrigations

The in vivo concentration-time profiles of chlorhexidine and noxythiolin bladder irrigations were determined by utilizing high-performance liquid chromatography techniques following a once daily irrigation. A total of 14 chlorhexidine irrigations established a mean concentration of 0.006% w/v, 2-3 h post irrigation. A total of 12 noxythiolin irrigations established a mean concentration of 0.266% w/v, 2-3 h post irrigation, which correlated to a mean formaldehyde concentration of 0.0119% w/v at 2-3 h, as estimated from N-methylthiourea. For both solutions the minimum inhibitory concentration was exceeded for up to 5 h post irrigation, which is sufficient contact time to establish a total kill, thus indicating the possibility that a once daily irrigation may be appropriate in asymptomatic bacteriuria which utilizes either chlorhexidine or noxythiolin.