Role of free fatty acids in regulating gastric emptying and gallbladder contraction.

The limited effectiveness of orlistat, an inhibitor of gastrointestinal lipases, in inhibiting fat digestion is not completely understood. Therefore we studied the effect of orally and duodenally administered orlistat on gastric emptying, cholecystokinin (CCK) secretion, and gallbladder contraction. In healthy males, gastric emptying of solids and fat were quantified scintigraphically, gallbladder contraction by ultrasound and CCK release by radioimmunoassay.

Rapid exchange of pancreatic lipase between triacylglycerol droplets.

Two types of experiments were performed to study the reversibility of interfacial adsorption of pancreatic lipase (PL) to fat droplets during lipolysis. Lipolysis was measured in olive oil/gum arabic emulsions containing radiolabeled triolein in the presence of bile salts and lecithin at rate-limiting concentrations of porcine PL (PPL) or human PL (HPL). The lipolysis rate in a labeled emulsion, i.

Magnetic resonance imaging for the in vivo evaluation of gastric-retentive tablets.

Purpose: To develop a magnetic resonance imaging (MRI) technique for assessing in vivo properties of orally ingested gastric-retentive tablets under physiologic conditions.

Methods: Tablets with different floating characteristics (tablet A-C) were marked with superparamagnetic Fe3O4 particles to analyze intragastric tablet position and residence time in human volunteers. Optimal Fe3O4 concentration was determined in vitro.

Natural abundance 13C-NMR spectroscopy for the quantitative determination of fecal fat.

Objective: To evaluate 13C-NMR spectroscopy as a method for fat quantitation in human feces without time consuming or unpleasant preparation steps.

Design And Methods: Stool samples of seven healthy subjects were collected for 18 days before and during oral intake of the inhibitor of gastrointestinal lipases Orlistat. Fecal lipid content was determined first using 13C-NMR, then by conventional gravimetry after homogenization and Bligh & Dyer lipid extraction.

Analysis of the meal-dependent intragastric performance of a gastric-retentive tablet assessed by magnetic resonance imaging.

Background: Modern medical imaging modalities can trace labelled oral drug dosage forms in the gastrointestinal tract, and thus represent important tools for the evaluation of their in vivo performance. The application of gastric-retentive drug delivery systems to improve bioavailability and to avoid unwanted plasma peak concentrations of orally administered drugs is of special interest in clinical and pharmaceutical research.

Aim: To determine the influence of meal composition and timing of tablet administration on the intragastric performance of a gastric-retentive floating tablet using magnetic resonance imaging in the sitting position.