Vergleichende Untersuchungen der histamin- und insulin-stimulierten Säure-Pepsin-Sekretion bei Patienten mit Ulcus duodeni und Kontrollpersonen<sup>*</sup>

Ha, Schmidt; Fritzlar, G; Dölle, W; Goebell, H.

doi:10.1055/s-0028-1108771

Cited by 13 publications

(7 citation statements)

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“…The pH in the gastric juice was 1.7, and the pH of the duodenal juice was 7.0 which correlated well with the aforementioned normal pH values observed by others [32, 34, 35, 40]. Basal pepsin output has previously been reported to be approximately 0.87 mg/ml pepsin [33, 41]. The pooled gastric juice ( n = 18) had a pepsin activity of 27 U/ml with an individual variation of 7 to 70 U/ml.…”

Section: Discussionsupporting

confidence: 85%

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

et al. 2011

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The aim of this study was to characterise the individual human gastric and duodenal juices to be used in in vitro model digestion and to examine the storage stability of the enzymes. Gastroduodenal juices were aspirated, and individual variations in enzymatic activities as well as total volumes, pH, bile acids, protein and bilirubin concentrations were recorded. Individual pepsin activity in the gastric juice varied by a factor of 10, while individual total proteolytic activity in the duodenal juice varied by a factor of 5. The duodenal amylase activity varied from 0 to 52.6 U/ml, and the bile acid concentration varied from 0.9 to 4.5 mM. Pooled gastric and duodenal juices from 18 volunteers were characterised according to pepsin activity (26.7 U/ml), total proteolytic activity (14.8 U/ml), lipase activity (951.0 U/ml), amylase activity (26.8 U/ml) and bile acids (4.5 mM). Stability of the main enzymes in two frozen batches of either gastric or duodenal juice was studied for 6 months. Pepsin activity decreased rapidly and adjusting the pH of gastric juice to 4 did not protect the pepsin from degradation. Lipase activity remained stable for 4 months, however decreased rapidly thereafter even after the addition of protease inhibitors. Glycerol only marginally stabilised the survival of the enzymatic activities. These results of compositional variations in the individual gastrointestinal juices and the effect of storage conditions on enzyme activities are useful for the design of in vitro models enabling human digestive juices to simulate physiological digestion.

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Section: Discussionsupporting

confidence: 85%

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

et al. 2011

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“…1). However, they are lower than the values found in the study of Lambert et al (38), where pepsin levels in gastric aspirates after intravenous administration of insulin or betazole (histalog) were reported to be 0.56Y1.72 mg mL j1 and also lower than the values found in the study of Schmidt et al (19), where values of 1.25 and 1.68 mg mL j1 were reported after stimulation with histamine or with insulin, respectively. Again, these differences can be attributed to differences in the study protocols; in the earlier studies, which recruited subjects hospitalized for various disorders, induction of the fed state was performed pharmacologically rather than by administration of a meal, leading to substantially lower intragastric volumes and thus, higher pepsin concentration.…”

Section: Fed Stomachcontrasting

confidence: 66%

“…In the literature, values reported for pepsin concentration are higher. Schmidt et al (19) report a value of 0.87 mg mL j1 (determined by hydrolysis of hemoglobin at pH 1.7 and by using hog pepsin as standard) and Lambert et al (38) reported values of 0.83Y1.27 mg mL j1 (determined with an analytical technique similar to that used in this study). An important methodological difference between the present and the previous studies is that no water seems to have been administered prior to collecting aspirates in the previous studies (19,38).…”

Section: Fasted Stomachmentioning

confidence: 90%

“…In addition to the buffer capacity, few or no data for osmolality and surface tension data in the fed state have been reported in the literature. Finally, in some studies, agents that induce the fed state rather than an actual meal have been administered to induce Bfed state^conditions (19,20). This would minimize the intralumenal volume generated and, as a result, the intralumenal concentrations may be exaggerated compared to those generated during a BA/ BE study.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of the Human Upper Gastrointestinal Contents Under Conditions Simulating Bioavailability/Bioequivalence Studies

et al. 2006

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“…Kalantzi et al found median pepsin levels in the fasted state to range from 0.11–0.22mg/mL14, while other researchers have found them to be between 0.1 and 1.3 mg/mL15–16. Pepsin in the fed state is typically higher and has been shown to range from 0.26 to 1.72 mg/mL14, 16.…”

Section: Composition Of the Gastrointestinal Fluidmentioning

confidence: 99%

Physiological Parameters for Oral Delivery and in Vitro Testing

Mudie

Amidon

Amidon³

2010

Mol. Pharmaceutics

406

328

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Pharmaceutical solid oral dosage forms must undergo dissolution in the intestinal fluids of the gastrointestinal tract before they can be absorbed and reach the systemic circulation. Therefore, dissolution is a critical part of the drug-delivery process. The rate and extent of drug dissolution and absorption depend on the characteristics of the active ingredient as well as properties of the dosage form. Just as importantly, characteristics of the physiological environment such as buffer species, pH, bile salts, gastric emptying rate, intestinal motility, and hydrodynamics can significantly impact dissolution and absorption. While significant progress has been made since 1970 when the first compendial dissolution test was introduced (USP Apparatus 1), current dissolution testing does not take full advantage of the extensive physiologic information that is available. For quality control purposes, where the question is one of lot-to-lot consistency in performance, using nonphysiologic test conditions that match drug and dosage form properties with practical dissolution media and apparatus may be appropriate. However, where in vitro – in vivo correlations are desired, it is logical to consider and utilize knowledge of the in vivo condition. This publication critically reviews the literature that is relevant to oral human drug delivery. Physiologically relevant information must serve as a basis for the design of dissolution test methods and systems that are more representative of the human condition. As in vitro methods advance in their physiological relevance, better in vitro - in vivo correlations will be possible. This will, in turn, lead to in vitro systems that can be utilized to more effectively design dosage forms that have improved and more consistent oral bioperformance.

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Vergleichende Untersuchungen der histamin- und insulin-stimulierten Säure-Pepsin-Sekretion bei Patienten mit Ulcus duodeni und Kontrollpersonen^*

Cited by 13 publications

References 0 publications

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

Characterization of the Human Upper Gastrointestinal Contents Under Conditions Simulating Bioavailability/Bioequivalence Studies

Physiological Parameters for Oral Delivery and in Vitro Testing

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Vergleichende Untersuchungen der histamin- und insulin-stimulierten Säure-Pepsin-Sekretion bei Patienten mit Ulcus duodeni und Kontrollpersonen*

Cited by 13 publications

References 0 publications

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models

Characterization of the Human Upper Gastrointestinal Contents Under Conditions Simulating Bioavailability/Bioequivalence Studies

Physiological Parameters for Oral Delivery and in Vitro Testing

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Vergleichende Untersuchungen der histamin- und insulin-stimulierten Säure-Pepsin-Sekretion bei Patienten mit Ulcus duodeni und Kontrollpersonen^*