Primary resistance to clarithromycin or amoxicillin may underscore a potentially serious problem for the eradication of H. pylori infection. Testing for bacterial resistance may become necessary to improve therapeutic efficacy.

A liquid chromatographic-tandem mass spectrometric method (LC-MS/MS) for quantifying amlodipine in human plasma was developed and validated. Sample preparation was based on liquid-liquid extraction using NaOH and a mixture of ethyl acetate/hexane (80/20; v/v). Chromatography was performed on a C-18 analytical column and the retention times were 1.9 and 3.0 min for amlodipine and nimodipine (internal standard), respectively. The ionization was optimized using ESI(+) and enhanced selectivity was achieved using tandem mass spectrometric analysis via two MRM functions, 409 --> 238 and 418 --> 343 for amlodipine and nimodipine. The calibration curve ranged from 0.2 to 20.0 ng/mL. The inter-day precision and accuracy and the relative standard deviation (RSD) were <15%. The analyte was shown to be stable over the time-scale of the whole procedure. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.

The results demonstrated that the test formulation was bioequivalent to the reference in fasting condition but not in postprandial state. The dissolution profile in FaSSIF indicates that this biorelevant medium was more adequate to discriminate the in vivo disposition of pantoprazole than FeSSIF. Furthermore, the fed condition study had shown a pronounced influence of food in the absorption of pantoprazole after single oral dose administration.

Background: The effects of proton pump inhibitors and Helicobacter pylori infection on the distribution of drugs used for the eradication of the bacteria are poorly understood. Aim: The aim of this study was to investigate the effects of a 7‐day administration of 20 mg of omeprazole on the pharmacokinetics of amoxicillin and ampicillin in the plasma, saliva and gastric juice of individuals with and without H. pylori infection. Methods: Fifty‐four healthy volunteers without endoscopic lesions were enrolled. Twenty‐six volunteers were included in the amoxicillin study and 28 individuals in the ampicillin study. Each study had an open randomized two‐period crossover design and a 21‐day washout period between phases. Plasma, saliva and gastric juice concentrations of amoxicillin and ampicillin in subjects with and without omeprazole pre‐treatment were measured by reversed‐phase HPLC using UV detection. Results: Neither pre‐treatment with omeprazole nor H. pylori infection interfered with the plasma bioavailability of amoxicillin or ampicillin, as assessed by the AUC0–2 h. Neither ampicillin nor amoxicillin were detected in saliva or gastric juice in any study phase. Conclusion: Short‐term treatment with omeprazole does not interfere with the pharmacokinetics of amoxicillin or ampicillin. Our results also exclude the presence of a transfer mechanism for amoxicillin or ampicillin from the plasma to the gastric lumen.

Purpose: The study was developed to compare the in vitro dissolution profile of pantoprazole (CAS 102625-70-7) formulations in both The United State Pharmacopeia (USP) apparatus 2 and by applying biorelevant medium. Moreover, an in vitro ? in vivo relationship was proposed considering in vivo data from previously published study Methods: In vitro dissolution profile were evaluated in biorelevant medium in USP apparatus 2 and 3 and the dissolution curves were either compared by the similarity factor (f2) or a model-independent approach. The fraction of drug dissolved in vitro in apparatus 2 was compared with the fraction of drug absorbed in vivo, which was obtained from a retro-spective in vivo study. An in vitro ? in vivo relationship analysis was then applied to elucidate the overall absorption characteristics of formulations Results: The dissolution profiles of formulations demonstrated similar disposition in biorelevant medium in both USP apparatus 2 and 3. The dissolution profiles were described by f2 model in apparatus 2 and Weibull's function in apparatus 3. The vitro?in vivo relationship analysis showed that the formulation exhibited permeability rate-limiting absorption. Conclusion: Biorelevant medium in both USP apparatus 2 and 3 may be used as a tool to predict in vivo disposition of formulations of pantoprazole. Furthermore, it can be argued that biowaiver can be granted for enteric coated formulations of pantoprazole on the basis of in vitro dissolution profile.