Non-clincal Bioequiavailability Investigation Of Pantoprazole Enteric Coated Tablet

Proton pump inhibitors （PPIs） are now universally considered the treatment for gastroesophageal reflux disease （GERD） as well as for the treatment of pathological hypersecretion associated with Zollinger-Ellison syndrome. Pantoprazole, the third proton pump inhibitor （PPI）, is characterized by its favorable pharmacokinetic properties, and its low potential to interact with concomitantly administered drugs and the cytochrome P450 enzyme system.The concentration of pantoprazole in plasma was determined by RP-HPLC method with UV-detection after single oral doses of pantoprazole enteric coated tablets to 8 Beagle dogs. The study was designed in a crossover, random, two-treatment, two-period test, bioequivalence of the two formulations was evaluated by ANONA and the two one-side t test. The in vitro release characteristics of two formulations were studied by determining their dissolution and evaluated with similarity factor method. The absorbed fractions were Loo-Riegelman’s formula, and a linear correlation was calculated by evaluated by using percent dissoluted data and percent absorbed data from two formulations at the corresponding timeS.The results of the pharmacokinetic parameters obtained after single oral administration of the two pantoprazole entetic coated tables were as following: C_max were （3.33±0.44） and （3.36±0.17）μg/mL, T_max were （3.50±0.38） and （3.56±0.42）h, t_1/2 were （1.924±0.048）and （2.240±0.115）h, AUC_0â†'12 were（10.29±1.03） and （10.55±1.17）μg·h/mL, AUC_{0â†'∞} were （10.82±0.93） and （11.07±1.15）μg·h/mL for test and reference tablets, respectively. The relative bioavailability of the test tablet was 97.60±1.76%.. The 90% confidence interval of AUC_0â†'12 about the test table was 100.7～96.4% by reference tablet; the 90% confidence interval of AUC_{0â†'∞} about the test table was 106.9～90.9% by reference tablet; the 90% confidence interval of C_max about the test table was106.9～90.9% by reference tablet.The similar factor was 99.97. After calculated with Akaike’ information criterion （AIC）, the pharmacokinetic process of pantoprazole enteric coated tables accord with two-compartment model, the correlation coeffcients are 0. 9932 for test table and 0. 9577 for reference tablet.The resule show that the pharmacokinetic parameters obtained after single oral administration of the two pantoprazole enteric coated tables showed that there were no significant difference between two formulations in AUC_0â†'12, AUC_{0â†'∞} and C_max. The dissolution rates between two formulations had no difference and the dissolution was similar. The results of correlation test showed the pantoprazole enteric coated tables had a satisfactory correlation between dissolution in vitro and absorption in vivo.