Gastrointestinal Water and Electrolytes. IV. The Equilibration of Deuterium Oxide (D2O) in Gastrointestinal Contents and the Proportion of Total Body Water (T.B.W.) in the Gastrointestinal Tract1

Polyethylene Glycol 400 Enhances the Bioavailability of a BCS Class III Drug (Ranitidine) in Male Subjects but Not Females

“…It is therefore feasible that PEG 400 has greater transit effects in females compared to males even at the lower doses studied, such that the lower doses of PEG 400 in the female volunteers has similar effects to those noted previously with higher doses of PEG 400 in male volunteers (1,3). Similarly, differences in small intestinal fluid volumes were noted in a study by Gotch et al investigating intraluminal fluid volumes in post-mortem humans (38). In the study females were noted to have lower small intestinal fluid volume than males (38).…”

“…Similarly, differences in small intestinal fluid volumes were noted in a study by Gotch et al investigating intraluminal fluid volumes in post-mortem humans (38). In the study females were noted to have lower small intestinal fluid volume than males (38). It is therefore possible that the actual intestinal PEG 400 concentration is different between gender; lower fluid volume in females may lead to higher concentrations of PEG 400 in the small intestine of females.…”

Interplay Between Intestinal pH, Transit Time and Feed Status on the In Vivo Performance of pH Responsive Ileo-Colonic Release Systems

“…The pH is below showing disintegration in the colon. Fluid volume plays an obvious role in the disintegration and dissolution of dosage forms and in the mean total water content of the small and large intestine has been reported to be just 206 ml (27), and 187 ml (28) respectively (at autopsy), but is highly variable between individuals and therefore likely to have implications for drug release. Of this total fluid, most is bound to digesta and only a proportion is free fluid available for interaction with dosage forms.…”

Interrelations Between Serum Sodium Concentration, Serum Osmolarity and Total Exchangeable Sodium, Total Exchangeable Potassium and Total Body Water1

“…Conversely, hypernatremia may reflect either a) primary sodium excess, b) primary potassium excess, c) primary water deficit or d) combinations of these. Hyponatremia in patients with gastrointestinal fluid loss probably results from loss of sodium and potassium (16,48,49). Hyponatremia in edematous subjects, on the other hand, appears to be a consequence of the loss of potassium and gain of water, as exemplified by Patients 28 and 47a in Table V.…”