Comparative pharmacokinetics and relative bioavailability for different preparations of nitrofurantoin.

In a single-dose study three different dosage forms of nitrofurantoin tablets are compared in order to attain a longer duration of efficacy by means of sustained-release dosage forms. In particular, bioavailability and the rate constants are estimated and show for one dosage form significant advantages. The measured serum and urine concentration levels are evaluated with a two-compartment model of first order which assumed the sustained release of the drug in an exponential manner.