Pharmacokinetics of a sustained release formulation of pyridoxal phosphate of buflomedil after single or repeated oral doses in healthy volunteers.

The pharmacokinetics of a sustained release (SR) formulation of pyridoxal phosphate of buflomedil (Pirxane retard) has been studied after oral administration to healthy volunteers using among else a gaschromatographic dosage method. After oral administration of 400 mg of the SR formulation, pyridoxal phosphate of buflomedil has a much slower kinetics compared to the normal formulation (tmax:approx. 1.5 h) reaching the maximum plasma concentration, which was about 467 ng/ml, in about 3 h. After 24 h the concentrations were still about 1/10 (48 ng/ml) the maximum value. 24-h urinary excretion was about 21% of the administered dose. Repeated administration of the SR formulation for 7 days in single daily doses of 400 mg gave steady state plasma levels (ca. 250 ng/ml) 12 h after the administration without statistically significant variations. The plasma concentrations of the drug measured daily after reaching the steady state were similar one to the other. The tolerability was very good and no local or systemic side effects of any kind were reported.