Animal experiment:

The pylorus of female Sprague-Dawley rats (160 to 220 g body weight) is ligated under ether anesthesia, the abdomen is closed and 100 mg/kg of acetylsalicylic acid (ASA) in 10 mL/kg are given orally. Following ASA administration, Pumaprazole (solution) or vehicle (i.v. saline or tap water in case of oral administration) is given i.v. in 1 mL/kg or i.d. in 2.5 mL/kg. Oral drug administration (in 10 mL/kg) is 1 h before pylorus ligation. Four hours after pylorus ligation, the stomach is excised, carefully keeping the esophagus closed, opened along the greater curvature and the luminal contents are removed, centrifuged, the volume is measured and the acidity determined by titration with 0.1 N NaOH to pH 7[1].

Pumaprazole is a reversible proton pump antagonist.

Pumaprazole is a reversible proton pump antagonist. Basal acid secretion in the Ghosh-Schild rat is inhibited by Pumaprazole with a higher efficacy compare to ranitidine. Pumaprazole displays identical ID50 values on day 1 (11 μmol/kg, 95% confidence limits of 5 and 23) and on day 7 (10 μmol/kg, 95% confidence limits of 4 and 23) of a repeated dose study in this model. The lower dose of Pumaprazole (27 μmol/kg) rapidly elevates luminal pH up to almost neutrality, the higher dose (54 μmol/kg) further prolongs this pH-elevating effect[1].

[1]. Kromer W, et al. Animal pharmacology of reversible antagonism of the gastric acid pump, compared to standard antisecretory principles. Pharmacology. 2000 May;60(4):179-87.