Evaluation of the pharmacological effect of Antareit® (oral suspension, 800 mg/10 ml) in healthy volunteers

The aim of the study was to evaluate the pharmacodynamic equivalence of the drugs Antareit® (oral suspension, 800 mg/10 ml; Valenta Pharm JSC, Russia) and Riopan® (chewable tablets, 800 mg; Takeda GmbH, Germany) based on their antacid activity. Material and methods. An open-label, two-period two-sequence crossover study was conducted to evaluate the pharmacodynamics of the test drug Antareit® (oral suspension, 800 mg/10 ml) and the reference drug Riopan® (chewable tablets, 800 mg), both administered as a single oral dose of 1600 mg. A total 50 healthy volunteers were randomized into two groups (n = 25) according to treatment sequence with a 7-day washout period between administrations. Gastric pH was continuously monitored for 1 hour after dosing using an intragastric pH probe placed in the gastric corpus. The main pharmacodynamics parameter was the area under the pH-time curve above baseline (AUCABL). Equivalence was determined by calculating the 90 % confidence interval (CI) for the ratio of marginal means of AUCABL between the two formulations. Safety was assessed through monitoring of adverse events (AEs), physical examinations, vital signs measurement, laboratory tests and electrocardiogram (ECG) findings. Results. A total of 48 out of 50 randomized subjects completed both periods of the study. Two volunteers discontinued before receiving the drug in period 2. The 90 % CI for the AUCABL was calculated using a mixed-effects model (MIXED) and a generalized linear model (GLM). The marginal mean AUCABL values were 68,81 for Antareit®, oral suspension, 800 mg/10 ml and 68,42 for Riopan®, chewable tablets, 800 mg based on GLM analysis. The AUCABL ratio (test drug / reference drug) was 100,57 % (90 % Cl: 82,44–122,69 %), indicating non-inferiority. Three AEs occurred in two subjects: two cases of rhinorrhea in one volunteer and one case of somnolence following drug administration. There were no statistically significant differences in the frequency of AEs between treatments. Conclusion. T he study established pharmacodynamic equivalence between the test drug Antareit®, oral suspension, 800 mg/10 ml and the reference drug Riopan®, chewable tablets, 800 mg. The safety profiles of both treatments were found to be similar, with no significant differences observed in either the incidence or severity of AE.