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Abstract

The pH in the upper gastrointestinal tract of young, healthy men and women was measured in the fasting state and after administration of a standard solid and liquid meal. Calibrated Heidelberg capsules were used to record the pH continuously over the study period of approximately 6 hr. In the fasted state, the median gastric pH was 1.7 and the median duodenal pH was 6.1. When the meal was administered the gastric pH climbed briefly to a median peak value of 6.7, then declined gradually back to the fasted state value over a period of less than 2 hr. In contrast to the pH behavior in the stomach, feeding a meal caused a reduction in the median duodenal pH to 5.4. In addition, there was considerable fluctuation in the postprandial duodenal pH on an intrasubject basis. The pH in the duodenum did not return to fasted state values within the 4-hr postprandial observation period. There was no tendency for the duodenal pH to be related to the gastric pH in either the fed or fasted phases of the study. Furthermore, pH in the upper GI tract of young, healthy subjects appears to be independent of gender. The differences in upper GI pH between the fasted and the fed state are discussed in terms of dosage form performance and absorption for orally administered drugs.

Colloidal Structures in Media Simulating Intestinal Fed State Conditions with and Without Lipolysis Products

“…The pH was set at 6.5 as a compromise between the optimum for the pancreas lipase, which is between 6 and 10 (34) and the measured duodenal pH, which is around 5.0-5.5 during a test meal (35,36). The experiment was performed under continuous agitation obtained by magnetic stirring (100 rpm) and the total volume of the medium was 300 mL.…”

The Campylobacter jejuni Ferric Uptake Regulator Promotes Acid Survival and Cross-Protection against Oxidative Stress

“…In order to establish a successful infection, enteric pathogens must survive the host stomach acidity (6). The stomach pH ranges from 1.5 to 5.5, depending on many variables, including the timing and type of food intake (7,8). Therefore, enteric pathogens have developed various strategies to sense and combat gastric acidity (6).…”

The Influence of Gastric Acidity and Taste Masking Agent on In Situ Gelling Pectin Formulations for Oral Sustained Delivery of Acetaminophen

“…6) However, at the upper limits of this pH range it is possible that the hydrogen ion concentration may not be sufficiently high to ensure adequate release of complexed calcium and hence gelation of the sols may not occur in all patients. In the present article we investigate the effects of pH change over the range 1 to 3 on the gelation and sustained release characteristics of pectin formulations in the presence and absence of the taste masking agent sorbitol.…”