Relevant pH and lipase for in vitro models of gastric digestion

2016 ◽  
Vol 7 (1) ◽  
pp. 30-45 ◽  
Author(s):  
Laura Sams ◽  
Julie Paume ◽  
Jacqueline Giallo ◽  
Frédéric Carrière
Keyword(s):  
Gastric Emptying ◽  
In Vitro Models ◽  
Individual Variability ◽  
Gastric Ph ◽  
Gastric Digestion ◽  
Ph Values

Expressing gastric pH as a function of gastric emptying instead of time makes it possible to reduce the inter-individual variability and highlight the pH values that are the most relevant for testing meal digestion in the stomach.

Evaluation of a system for intragastric pH monitoring of intensive care unit patients: preliminary report

1992 ◽  
Vol 1 (1) ◽  
pp. 81-84 ◽  
Author(s):  
JM Clochesy
Keyword(s):  
Ph Monitoring ◽  
Gastric Ph ◽  
Gastric Aspirate ◽  
Ph Probe ◽  
Buffer Solutions ◽  
Ph Values ◽  
Small Series ◽  
Significant Difference

BACKGROUND: A new pH probe-tipped nasogastric sump tube is available to monitor gastric pH conveniently. This study assesses its ability to measure gastric acidity accurately. METHODS: The accuracy of the combined pH probe nasogastric tube (GrapHprobe ST) was determined by comparing it with standard buffer solutions (pH 1.0, 2.0, 4.0 and 7.0) traceable to the National Institute of Standards and Technology. Gastric pH values obtained were compared with values obtained using indicator paper and a calibrated glass electrode on gastric aspirate. RESULTS: Although statistically significant differences were found in vitro between the pH of three of the buffer solutions and the pH values obtained by the nasogastric sump tube, the results were within 0.5 pH unit. When rounded to the nearest pH unit, all values were the same as the buffer solutions. No significant difference was found in the pH values obtained during in vivo testing. CONCLUSIONS: The GrapHprobe ST measured gastric pH within reasonable accuracy in this small series.

Disintegration kinetics of food gels during gastric digestion and its role on gastric emptying: an in vitro analysis

2015 ◽  
Vol 6 (3) ◽  
pp. 756-764 ◽  
Author(s):  
Qing Guo ◽  
Aiqian Ye ◽  
Mita Lad ◽  
Maria Ferrua ◽  
Douglas Dalgleish ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Functional Foods ◽  
Gastric Digestion ◽  
Vitro Analysis ◽  
Kinetics Of ◽  
In Vitro Analysis

The understanding of the disintegration and gastric emptying of foods in the stomach is important for designing functional foods.

Impact of gastric pH profiles on the proteolytic digestion of mixed βlg-Xanthan biopolymer gels

2016 ◽  
Vol 7 (1) ◽  
pp. 58-68 ◽  
Author(s):  
B. L. Dekkers ◽  
E. Kolodziejczyk ◽  
S. Acquistapace ◽  
J. Engmann ◽  
T. J. Wooster
Keyword(s):  
Gastric Ph ◽  
Proteolytic Digestion ◽  
Gastric Digestion ◽  
Ph Profile ◽  
Biopolymer Gels ◽  
Ph Profiles

Gastric pH profile duringin vitrogastric digestion is critical for proper assessment of mixed biopolymer gel proteolysis.

scholarly journals Effects of Lansoprazole and Amoxicillin on Uptake of [14C]Clarithromycin into Gastric Tissue in Rats

2001 ◽  
Vol 45 (12) ◽  
pp. 3451-3455 ◽  
Author(s):  
Hiromi Endo ◽  
Hideo Yoshida ◽  
Naoko Ohmi ◽  
Shohei Higuchi
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Gastric Emptying ◽  
Eradication Therapy ◽  
Gastric Ph ◽  
Gastric Tissue ◽  
Ulcer Disease ◽  
In Vitro Uptake ◽  
Apparent Influence

ABSTRACT Triple therapy consisting of clarithromycin (CLR), lansoprazole (LPZ), and amoxicillin (AMZ) is effective as eradication therapy for patients with peptic ulcer disease and Helicobacter pylori infection. We evaluated the effects of LPZ and AMZ on the uptake of [14C]CLR into the gastric tissue of rats. After administration of [14C]CLR alone or in combination with LPZ and AMZ, the distributions of [14C]CLR in the main organs and gastrointestinal tissues were compared. LPZ and AMZ had no effect on the distribution of [14C]CLR in any tissue except gastric tissue. The concentration of radioactivity in gastric tissue was several times higher when [14C]CLR was administered orally together with LPZ than when it was administered alone. The gastric emptying of [14C]CLR became smaller in the case of the coadministration of LPZ. AMZ had no apparent influence on the disposition of [14C]CLR. After the intravenous administration of [14C]CLR, no effects of drug coadministration were evident. In vitro uptake of [14C]CLR into gastric tissue was enhanced in the case of a high-pH environment. The uptake was not influenced by the concurrent presence of LPZ and AMZ. These results suggest that the penetration of [14C]CLR possibly depends on elevated gastric pH, as gastric acid secretion was inhibited by LPZ, and this may be a primary factor in explaining why the concentration of [14C]CLR at the target site, gastric tissue, was enhanced by the coadministration of LPZ.

scholarly journals Comparison of lipases for in vitro models of gastric digestion: lipolysis using two infant formulas as model substrates

2016 ◽  
Vol 7 (9) ◽  
pp. 3989-3998 ◽  
Author(s):  
P. J. Sassene ◽  
M. Fanø ◽  
H. Mu ◽  
T. Rades ◽  
S. Aquistapace ◽  
...  
Keyword(s):  
In Vitro Models ◽  
Infant Formulas ◽  
Gastric Digestion ◽  
Gastric Lipase

The aim of this study was to find a surrogate for Human Gastric Lipase (HGL), since the development of gastrointestinal lipolysis models are hampered by the lack of a lipase with similar digestive properties as HGL.

scholarly journals Distinct Effects of Inflammation on Cytochrome P450 Regulation and Drug Metabolism: Lessons from Experimental Models and a Potential Role for Pharmacogenetics

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1509
Author(s):  
Laura M. de Jong ◽  
Wim Jiskoot ◽  
Jesse J. Swen ◽  
Martijn L. Manson
Keyword(s):  
Cytochrome P450 ◽  
Drug Metabolism ◽  
Drug Response ◽  
Genetic Factors ◽  
Potential Role ◽  
In Vitro Models ◽  
Experimental Models ◽  
Individual Variability ◽  
The Individual

Personalized medicine strives to optimize drug treatment for the individual patient by taking into account both genetic and non-genetic factors for drug response. Inflammation is one of the non-genetic factors that has been shown to greatly affect the metabolism of drugs—primarily through inhibition of cytochrome P450 (CYP450) drug-metabolizing enzymes—and hence contribute to the mismatch between the genotype predicted drug response and the actual phenotype, a phenomenon called phenoconversion. This review focuses on inflammation-induced drug metabolism alterations. In particular, we discuss the evidence assembled through human in-vitro models on the effect of inflammatory mediators on clinically relevant CYP450 isoform levels and their metabolizing capacity. We also present an overview of the current understanding of the mechanistic pathways via which inflammation in hepatocytes may modulate hepatic functions that are critical for drug metabolism. Furthermore, since large inter-individual variability in response to inflammation is observed in human in-vitro models and clinical studies, we evaluate the potential role of pharmacogenetic variability in the inflammatory signaling cascade and how this can modulate the outcome of inflammation on drug metabolism and response.

scholarly journals WPI Gel Microstructure and Mechanical Behaviour and Their Influence on the Rate of In Vitro Digestion

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1066
Author(s):  
Stephen Homer ◽  
Roderick Williams ◽  
Allison Williams ◽  
Amy Logan
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
In Vitro Digestion ◽  
Protein Isolate ◽  
In Vitro Digestibility ◽  
Gastric Digestion ◽  
Intestinal Phase ◽  
Ph Values ◽  
Oral Processing

The influence of microstructure and mechanical properties on the in vitro digestibility of 15% whey protein isolate (WPI) gels was investigated. Gels were prepared via heat set gelation at three pH values (pH 3, 5 and 7), which produced gels with distinct microstructures and mechanical properties. The gels were minced to simulate an oral/chewing phase, which led to the formation particles of various sizes and textures. The minced gels were passed through either an Infogest (pre-set pH of 3) or Glass stomach (dynamic pH) protocol. Gels were digested in the gastric phase for up to 120 min, at which point the extent of digestion was measured by the amount of filterable nitrogen passing through a sieve. The digesta from both gastric methods were passed through an in vitro simulated intestinal phase. A strong link was found between the elasticity of the initial gel and the gel particle size following simulated oral processing, which significantly (p < 0.01) affected the rate of digestion in the gastric phase. A weaker correlation was also found between the pH of the gels and the extent of gastric digestion. This work highlights the differences in the rate of gastric digestion, arising from oral processing, which can be attributed to the material properties of the substrate.

scholarly journals Bioequivalence of Oral Drug Products in the Healthy and Special Populations: Assessment and Prediction Using a Newly Developed In Vitro System “BE Checker”

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1136
Author(s):  
Takato Masada ◽  
Toshihide Takagi ◽  
Keiko Minami ◽  
Makoto Kataoka ◽  
Ken-ichi Izutsu ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Environmental Changes ◽  
Gastric Ph ◽  
Oral Drug ◽  
Basic Drug ◽  
In Vitro System ◽  
Drug Products ◽  
Gastric Emptying Time ◽  
Emptying Time

In order to assess and predict the bioequivalence (BE) of oral drug products, a new in vitro system “BE checker” was developed, which reproduced the environmental changes in the gastrointestinal (GI) tract by changing the pH, composition, and volume of the medium in a single chamber. The dissolution and membrane permeation profiles of drugs from marketed products were observed in the BE checker under various conditions reflecting the inter-patient variations of the GI physiology. As variable factors, initial gastric pH, gastric emptying time, and GI agitation strength were varied in vitro. Dipyridamole, a basic drug, showed rapid and supersaturated dissolution when the paddle speed in the donor chamber was 200 rpm, which corresponds to the high agitation strength in the stomach. In contrast, supersaturated dissolution disappeared, and the permeated amount decreased under the conditions with a slow paddle speed (100 and 50 rpm) and short gastric emptying time (10 min). In those conditions, disintegration of the formulation was delayed, and the subsequent dissolution of dipyridamole was not completed before the fluid pH was changed to neutral. Similar results were obtained when the initial gastric pH was increased to 3.0, 5.0, and 6.5. To investigate that those factors also affect the BE of oral drug products, dissolution and permeation of naftopidil from its ordinary and orally disintegrating (OD) tablets were observed in the BE checker. Both products showed the similar dissolution profiles when the paddle speed and gastric emptying time were set to 100 rpm and 10 or 20 min, respectively. However, at a low paddle speed (50 rpm), the dissolution of naftopidil from ordinary tablets was slower than that from the OD tablets, and the permeation profiles became dissimilar. These results indicated the possibility of the bioinequivalence of some oral formulations in special patients whose GI physiologies are different from those in the healthy subjects. The BE checker can be a highly capable in vitro tool to assess the BE of oral drug products in various populations.

Acid and Moisture Uptake into Red Beets during in Vitro Gastric Digestion as Influenced by Gastric pH

2020 ◽  
Vol 15 (2) ◽  
pp. 261-272 ◽  
Author(s):  
Yamile A. Mennah-Govela ◽  
Silvia Keppler ◽  
Felipe Januzzi-Guerreiro ◽  
Camila Follador-Lemos ◽  
Karine Vilpont ◽  
...  
Keyword(s):  
Gastric Ph ◽  
Moisture Uptake ◽  
Gastric Digestion

Digestion and absorption of food: usefulness and limitations of in vitro models

1994 ◽  
Vol 72 (4) ◽  
pp. 407-414 ◽  
Author(s):  
L. Savoie
Keyword(s):  
Release Kinetics ◽  
In Vitro Models ◽  
Physiological Adaptation ◽  
Reaction Products ◽  
Gastric Digestion ◽  
Mode Of Operation ◽  
One Step ◽  
Acid Release ◽  
Kinetics Of

The digestion and absorption of food is a spatiotemporal and dynamic process involving complex enzymatic and transport reactions, and it is illusive to try to reproduce in a single model all these biochemical and physiological events. A more practical and realistic approach is to separately evaluate the specific contributions of oral and gastric digestion, intestinal digestion by pancreatic enzymes, brush-border hydrolysis, and eventually intestinal absorption and enterocyte metabolism. The models proposed must be versatile enough to be able to modify their conditions of operation according to physiological adaptation to food. Enzymatic preparations must be kept close to physiological conditions in regard to their nature and their mode of operation. A digestion cell and a peptidase bioreactor were developed for this purpose. The challenge is to find a way to integrate all these data. This can be partially achieved by selecting techniques that allow the collection and isolation of reaction products from one step for use as substrates for the next event. Various models are presented to illustrate this concept as applied to food protein.Key words: digestion, proteolysis, in vitro models, amino acid release, kinetics of digestion.

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