Disposition of [14C]povidone after oral administration to the rat

The tissue distribution and excretion of 14C-labelled povidone (polyvinylpyrrolidone; K-30; average mol wt 40,000) was studied in male Sprague-Dawley rats given a single oral dose. The major pathway of elimination of radioactivity was in the faeces, in which 90.8% of the administered dose was recovered after 12 hr and 98.4% after 48 hr. Amounts of radioactivity in major tissues and in the blood were not significantly different from those in untreated controls. A minor amount of radioactivity, representing 0.04% of the administered dose, was detected in the urine after 6 hr. Dialysis studies of [14C]povidone suggested that the absorbed species was a low-molecular-weight (less than 3500) oligomer. It was concluded that an oral dose of [14C]povidone is not significantly absorbed in the rat.