Propantheline bromide plasma level, urinary excretion and pharmacological data in a comparison of the bioavailability of three oral formulations of Pro-Banthine.

To determine the comparative bioavailability of three oral formulations of propantheline bromide (PB) by both pharmacokinetic and pharmacodynamic parameters, six normal men received three standard Pro-Banthine 15 mg tablets, two prolonged acting (PA) Pro-Banthine 30 mg tablets or one developmental PA Pro-Banthine 45 mg capsule, in a study of balanced random crossover design. Plasma concentrations and urinary excretion of the unchanged drug were measured after each treatment using a stable isotope dilution assay. Salivary secretion rate and heart rate measurements were also made at intervals after each medication. The standard Pro-Banthine formulation was significantly more bioavailable, weight for weight, than either the developmental PA capsule (45 mg), p less than 0.05, or the two 30 mg PA tablets (60 mg), p less than 0.01, based on urinary excretion and plasma levels of PB and on salivary secretion and heart rate data. There was no evidence of significant prolonged action for the PA formulations.