Evaluation of gastrointestinal pH and gastric residence time via the Heidelberg radiotelemetry capsule: Pharmaceutical application

ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats

“…Dogs have lower basal acid secretory rates but considerably higher peak gastric acid responses compared to humans, but these early data are mostly derived from experiments using pharmacologic stimulation of gastric acid secretion in dogs and cats with surgically placed gastric fistulas . Although higher fasting gastric pH was reported in some studies, fasting gastric pH was comparable in dogs, cats, and humans in more recent studies . The intragastric pH of healthy control dogs measured with a catheter‐less pH capsule remained <2.0 >85% of the time, with a mean percentage time (MPT) intragastric pH > 4.0 of only 4.7% .…”

The dynamic gastric environment and its impact on drug and formulation behaviour

“…An indigestible Heidelberg Capsule (HC) can be used to investigate gastric residence of an indigestible solid dosage form. The HC measures intraluminal pH, making it possible to deduce the exact time of gastric emptying from a steep rise in pH (Mojaverian, 1996). Mojaverian et al administered an enteric-coated aspirin-containing dosage form together with a Heidelberg capsule (HC) to fasting volunteers.…”

Calculation of the relative metastabilities of proteins in subcellular compartments of Saccharomyces cerevisiae

“…In order to fill in the table as completely as possible, it was necessary to consider measurements performed on eukaryotic cells other than those of S. cerevisiae (e.g., HeLa [80] and mouse hybridoma [81] cells). The values of pH required for conversion of Eh to log f O2 (g) were also retrieved from the literature [83,6,7]. The computation of log f O2 (g) from Eh was performed at 25 • C and 1 bar and with log a H2O = 0.…”

“…f. Calculated by combining the law of mass action for Fe +3 + e − Fe +2 (standard molal Gibbs energies taken from [82]) with a Fe +3 = a Fe +2 (see text). g. [83] (Homo sapiens). h. [6] (yeast).…”