[Biopharmaceutic investigations with D-norpseudoephedrine (author's transl)].
The concentrations of D-norpseudoephedrine in the plasma of 6 healthy persons were measured after the oral administration of 60 mg D-norpseudoephedrinehydrochloride in a hard gelatin capsule. One-compartment open-model parameters were derived from the blood levels. No gastric absorption was observed. The intestinal absorption started after a lag time of 0.31 h with an absorption constant of 1.75 h-1. The maximum of plasma concentration with 200 ng D-norpseudoephedrine/ml plasma was reached after 1.3 h. The following monoexponential decay of the plasma concentration curve had a half-life of 3 h. 24 h after ingestion no remaining D-norpseudoephedrine could be detected in the plasma. In vitro absorption constants were measured with the Sartorius-Resorptionsmodell. The in vitro results agreed with the in vivo results. The dissociation constant of D-norpseudoephedrine was determined (pKa = 8.92) with a non-logarithmic titration method.
D000042:Absorption; D000284:Administration, Oral; D002214:Capsules; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D008954:Models, Biological; D010665:Phenylpropanolamine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
D002214:Capsules; D008567:Membranes, Artificial; D010665:Phenylpropanolamine
Biopharmazeutische Untersuchungen and D-Norpseudoephedrin