Assays - Pirenzepine

Bioavailability studies with Pirenzepine using a new HPLC-method

Author: H. Vergin, H.J. Mascher, K. Strobel und V. Nitsche
Publisher: Acta Pharmacologica et toxicologica 59 (1986), 207

Pharmacokinetics and Bioequivalence of Different Formulations of Pirenzepine

Author: H. Vergin, H.J. Mascher, K. Strobel, V. Nitsche
Publisher: Arzneim.-Forsch./Drug Res. 36 (1986), 1409-1412

An intraindividual comparative single-dose study was carried out under carefully controlled conditions on 12 healthy volunteers in order to establish the bioavailability of 5,11-dihydro-11-[(4-methyl-piperazin-1-yl)acetyl]-6H-pyrido[2,3b][1,4]benzodiazepin-6-one dihydrochloride (pirenzepine), the active principle of newly developed tablets (Gastricur ®) and suspension containing 10 mg. In an additional multiple dose, cross-over study on 12 healthy volunteers, the bioequivalence of pirenzepine was investigated after administration of the newly developed vs. commercial dose-equivalent tablets. Pirenzepine was assayed from plasma by a new, highly sensitive high-performance liquid chromatography method. A 3-compartment model was taken as a basis for the calculation of the plasma concentration curves and the pharmacokinetic parameters. Following i.v. administration, the terminal elimination half-life, the volume of distribution, and the total plasma clearance were determined to be 7.7 h, 0.255 l/kg and 263.4 ml/min, respectively. From the tablet and suspension formulation the systemic availabilities were calculated to be 33.5 % and 20. 3 %, respectively. In the multiple dose study, both tablet forms investigated were bioequivalent.