The Suitability of an in Situ Perfusion Model for Permeability Determinations:  Utility for BCS Class I Biowaiver Requests

The aim of this study was to examine the integrative response to neurokinin A (NKA) on duodenal mucosal permeability, bicarbonate secretion, fluid flux, and motility in an in situ perfusion model in anesthetized rats. Intravenous infusion of NKA (100, 200, and 400 pmol ⋅ kg−1 ⋅ min−1) induced duodenal motility. Furthermore, duodenal mucosal bicarbonate secretion, fluid output, and mucosal permeability increased in response to NKA. Pretreatment with the nicotinic antagonist hexamethonium did not change the response in any of the parameters investigated, whereas the NK2-receptor antagonist MEN 10,627 effectively inhibited all responses to NKA. Indomethacin induced duodenal motility and stimulated bicarbonate secretion. In indomethacin-treated rats, NKA further increased motility but decreased indomethacin-stimulated bicarbonate secretion by 70%. The NKA-induced increase in mucosal permeability was unaltered by indomethacin. It is concluded that NKA not only induces motility but also increases mucosal permeability and fluid output. Furthermore, the neuropeptide may have both stimulative and inhibitory effects on bicarbonate secretion. All responses to NKA are dependent on NK-2 receptor activation but are not mediated through nicotinic receptors.

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Absorption Barriers in the Rat Intestinal Mucosa: 1. Application of an In Situ Perfusion Model to Simultaneously Assess Drug Permeation and Metabolism

Journal of Pharmaceutical Sciences ◽

10.1002/jps.21912 ◽

2010 ◽

Vol 99 (2) ◽

pp. 982-998 ◽

Cited By ~ 12

Author(s):

Daniel R. Mudra ◽

Ronald T. Borchardt

Keyword(s):

Intestinal Mucosa ◽

Drug Permeation ◽

In Situ Perfusion ◽

Perfusion Model

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Synthesis and Evaluation of PEG-PR for Water Flux Correction in an In Situ Rat Perfusion Model

Molecules ◽

10.3390/molecules25215123 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5123

Author(s):

Guo Chen ◽

Xingqi Min ◽

Qunqun Zhang ◽

Zhiqiang Zhang ◽

Meiqiang Wen ◽

...

Keyword(s):

Polyethylene Glycol ◽

Water Flux ◽

Phenol Red ◽

Scanning Calorimetry ◽

Flux Correction ◽

Apparent Permeability ◽

In Situ Perfusion ◽

Perfusion Model ◽

Intestinal Membrane

Phenol red (PR) is a widely used marker for water flux correction in studies of in situ perfusion, in which intestinal absorption usually leads to the underestimation of results. In this paper, we propose a novel marker polyethylene glycol (PEG)-PR (i.e., PR modified by PEGylation) with less permeability and evaluate its application in an in situ perfusion model in rats. PEG-PR was synthesized by the chemical conjunction of polyethylene glycol-4k/5k (PEG-4k/5k) and PR. The synthesized PEG-PR was then characterized using 1H-NMR, 13C-NMR, ultraviolet (UV), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analyses. The low permeability of PEG-PR was assessed using everted gut sac (EGS) methods. The apparent permeability coefficients (Papp, 3–8 × 10−7 cm/s) of PEG4k/5k-PR exhibited a nearly 15-fold reduction compared to that of PR. The different concentrations of PEG4k/5k-PR did not contribute to the Papp value or cumulative permeable percentage (about 0.02–0.06%). Furthermore, the larger molecular weight due to PEGylation (PEG5k-PR) enhanced the nonabsorbable effect. To evaluate the potential application of the novel marker, atenolol, ketoprofen, and metoprolol, which represent various biopharmaceutics classification system (BCS) classes, were selected as model drugs for the recirculation perfusion method. The water flux corrected by PEG4k/5k-PR reflected the accuracy due to the nonabsorbable effect, while the effective intestinal membrane permeability (Peff) of atenolol corrected by PEG4k/5k-PR showed a statistically significant increase (p < 0.05) in different intestinal segments. In conclusion, PEG-PR is a promising marker for the permeability estimation when using the in situ perfusion model in rats.

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Oleacein Intestinal Permeation and Metabolism in Rats Using an In Situ Perfusion Technique

Pharmaceutics ◽

10.3390/pharmaceutics13050719 ◽

2021 ◽

Vol 13 (5) ◽

pp. 719

Author(s):

Anallely López-Yerena ◽

Maria Pérez ◽

Anna Vallverdú-Queralt ◽

Eleftherios Miliarakis ◽

Rosa M. Lamuela-Raventós ◽

...

Keyword(s):

Intestinal Permeability ◽

Model Compound ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Perfusion Technique ◽

In Situ Perfusion ◽

First Pass ◽

Health Promoting ◽

Intestinal Permeation

Oleacein (OLEA) is one of the most important phenolic compounds in extra virgin olive oil in terms of concentration and health-promoting properties, yet there are insufficient data on its absorption and metabolism. Several non-human models have been developed to assess the intestinal permeability of drugs, among them, single-pass intestinal perfusion (SPIP), which is commonly used to investigate the trans-membrane transport of drugs in situ. In this study, the SPIP model and simultaneous luminal blood sampling were used to study the absorption and metabolism of OLEA in rats. Samples of intestinal fluid and mesenteric blood were taken at different times and the ileum segment was excised at the end of the experiment for analysis by LC–ESI–LTQ–Orbitrap–MS. OLEA was mostly metabolized by phase I reactions, undergoing hydrolysis and oxidation, and metabolite levels were much higher in the plasma than in the lumen. The large number of metabolites identified and their relatively high abundance indicates an important intestinal first-pass effect during absorption. According to the results, OLEA is well absorbed in the intestine, with an intestinal permeability similar to that of the highly permeable model compound naproxen. No significant differences were found in the percentage of absorbed OLEA and naproxen (48.98 ± 12.27% and 43.96 ± 7.58%, respectively).

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