In-vitro respiratory drug absorption models possess nominal functional P-glycoprotein activity

2009 ◽  
Vol 61 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Michaela Madlova ◽  
Cynthia Bosquillon ◽  
Dan Asker ◽  
Pavel Dolezal ◽  
Ben Forbes
Keyword(s):  
Drug Absorption ◽  
P Glycoprotein ◽  
Absorption Models

In-vitro respiratory drug absorption models possess nominal functional P-glycoprotein activity

2009 ◽  
Vol 61 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Michaela Madlova ◽  
Cynthia Bosquillon ◽  
Dan Asker ◽  
Pavel Dolezal ◽  
Ben Forbes
Keyword(s):  
Drug Absorption ◽  
P Glycoprotein ◽  
Absorption Models

Ginsenoside Metabolites Inhibit P-Glycoprotein In Vitro and In Situ Using Three Absorption Models

Planta Medica ◽  
2014 ◽  
Vol 80 (04) ◽  
pp. 290-296 ◽  
Author(s):  
Na Li ◽  
Dandan Wang ◽  
Guangbo Ge ◽  
Xiuli Wang ◽  
Yong Liu ◽  
...  
Keyword(s):  
P Glycoprotein ◽  
Absorption Models

scholarly journals Intraluminal Behavior of Various Transporter Substrates in the Rat Gastrointestinal Tract

2021 ◽  
Vol 24 ◽  
pp. 563-570
Author(s):  
Yusuke Tanaka ◽  
Taiki Harada ◽  
Kazuhiro Ito ◽  
Takanori Kurakazu ◽  
Satoshi Kasaoka
Keyword(s):  
Drug Absorption ◽  
Residual Water ◽  
Glycoprotein P ◽  
Transport Studies ◽  
P Glycoprotein ◽  
Drug Concentrations ◽  
Optimal Drug ◽  
Actual Contribution ◽  
Knockout Animals

Purpose: The aim of this study was to evaluate the intraluminal behavior of various transporter substrates in different regions of the gastrointestinal (GI) tract. Methods: Drug solutions containing non-absorbable FITC-dextran 4000 (FD-4), were orally administered to rats. Residual water was sampled from the GI regions to measure the luminal drug concentration. Results: Cephalexin (CEX), a substrate of the proton-coupled oligopeptide transporter, was absorbed rapidly, and no drug was detected in the lower small intestine. Saquinavir (SQV) was primarily absorbed in the upper region. However, unlike CEX, SQV was detected even in the lower segment probably due to the efflux of SQV via P-glycoprotein (P-gp). The concentration of methotrexate (MTX) showed a similar pattern to that of non-absorbable FD-4. The low absorption of MTX was probably due to efflux via several efflux transporters, and the limited expression of proton-coupled folate transporter, an absorptive transporter for MTX, in the upper region. Conclusion: This study revealed that the luminal concentration pattern of each drug differed considerably depending on the site because of the different absorption properties and luminal volumes. Although further investigation using a specific transporter inhibitor or transporter-knockout animals are necessary to clarify the actual contribution of each transporter to the drug absorption, this information will be valuable in evaluating transporter-mediated drug absorption in in vitro transport studies for ensuring optimal drug concentrations.

Drug-excipient interactions by Vitamin E-TPGS: in vitro studies on inhibition of P-glycoprotein and colonic drug absorption

2008 ◽  
Vol 18 (2) ◽  
pp. 145-148 ◽  
Author(s):  
B. Bittner ◽  
R.C. Bravo González ◽  
B. Bohrmann ◽  
M. Kuentz ◽  
J. Huwyler
Keyword(s):  
Vitamin E ◽  
Drug Absorption ◽  
In Vitro Studies ◽  
P Glycoprotein ◽  
Vitamin E Tpgs ◽  
Excipient Interactions

Scaling of in Vitro Membrane Permeability to Predict P-glycoprotein-Mediated Drug Absorption in Vivo

2008 ◽  
Vol 36 (5) ◽  
pp. 916-922 ◽  
Author(s):  
Yoshiyuki Shirasaka ◽  
Yoshie Masaoka ◽  
Makoto Kataoka ◽  
Shinji Sakuma ◽  
Shinji Yamashita
Keyword(s):  
Membrane Permeability ◽  
Drug Absorption ◽  
P Glycoprotein

Novel Swellable/Expandable Gastroretentive Floating Films of Gliclazide Folded in Capsule Shell for the Effective Management of Diabetes Mellitus: Formulation Development, Optimization and In vitro Evaluation

2020 ◽  
Vol 15 ◽  
Author(s):  
Diksha Sharma ◽  
Deepak Sharma
Keyword(s):  
Diabetes Mellitus ◽  
Drug Absorption ◽  
Gastric Fluid ◽  
Stability Study ◽  
Gastric Retention ◽  
Effective Management ◽  
In Vitro Evaluation ◽  
Capsule Shell ◽  
Study Results

Background: Gliclazide (GLZ) belongs to the second-generation of sulphonylureas, is a drug of choice for the management of type II DM. It belongs to BCS Class II. The major site of drug absorption for GLZ is the stomach; it displayed variation in the drug absorption rate and bioavailability due to the shorter gastric retention time. Floating mechanism performance gets affected when the gastric fluid level not sufficiently higher, which ultimately obstructs the floating behavior, which is the major limitation of reported formulations. This limitation can get over by folded the film into the capsule shell that dissolved in gastric fluid and film swell/expands to dimensions higher than pylorus sphincter (12mm), thus prevents its evacuation. Objective: To explore the floating mechanism in the designing of films along with a tendency to expand by swelling and unfolding by utilizing a mixture of hydrophilic and hydrophobic polymer to achieve the controlled drug delivery and prolonged gastric retention of drug. Methods: The gastroretentive floating films were formulated by the solvent casting technique using 32 full factorial design and subjected to in vitro evaluation parameters, drug-excipient compatibility, X-ray diffraction and accelerated stability study. Results: The pre-formulation study established the purity and identification of drug. FTIR study confirmed no drug excipient interaction. F3, F6, and F9 were optimized based on in vitro floating characteristics, swelling/expanding ability, and unfolding time study. All developed formulations were unfolded within 14-22 min after capsule disintegration. The F3 was selected as final formulation as its ability to control the release of drug for 24 hrs followed by Zero-order kinetics having super case 2 transport. XRD confirmed the amorphousness of drug within formulation. The stability study results revealed that formulation was quite stable at extreme storage condition. Conclusion: The developed novel formulation has a good potential for the effective management and treatment of Diabetes Mellitus.

scholarly journals Generation of tetracycline-controllable CYP3A4-expressing Caco-2 cells by the piggyBac transposon system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Moe Ichikawa ◽  
Hiroki Akamine ◽  
Michika Murata ◽  
Sumito Ito ◽  
Kazuo Takayama ◽  
...  
Keyword(s):  
Small Intestine ◽  
Drug Absorption ◽  
Cell Model ◽  
Negative Effects ◽  
Piggybac Transposon ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme ◽  
Cyp3a4 Expression

AbstractCaco-2 cells are widely used as an in vitro intestinal epithelial cell model because they can form a monolayer and predict drug absorption with high accuracy. However, Caco-2 cells hardly express cytochrome P450 (CYP), a drug-metabolizing enzyme. It is known that CYP3A4 is the dominant drug-metabolizing enzyme in human small intestine. In this study, we generated CYP3A4-expressing Caco-2 (CYP3A4-Caco-2) cells and attempted to establish a model that can simultaneously evaluate drug absorption and metabolism. CYP3A4-Caco-2 cells were generated by piggyBac transposon vectors. A tetracycline-controllable CYP3A4 expression cassette (tet-on system) was stably transduced into Caco-2 cells, thus regulating the levels of CYP3A4 expression depending on the doxycycline concentration. The CYP3A4 expression levels in CYP3A4-Caco-2 cells cultured in the presence of doxycycline were similar to or higher than those of adult small intestine. The CYP3A4-Caco-2 cells had enough ability to metabolize midazolam, a substrate of CYP3A4. CYP3A4 overexpression had no negative effects on cell proliferation, barrier function, and P-glycoprotein activity in Caco-2 cells. Thus, we succeeded in establishing Caco-2 cells with CYP3A4 metabolizing activity comparable to in vivo human intestinal tissue. This cell line would be useful in pharmaceutical studies as a model that can simultaneously evaluate drug absorption and metabolism.

scholarly journals Overexpression of P-glycoprotein, MRP2, and CYP3A4 impairs intestinal absorption of octreotide in rats with portal hypertension

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoyu Sun ◽  
Shunxiong Tang ◽  
Binbin Hou ◽  
Zhijun Duan ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Liver Cirrhosis ◽  
Portal Hypertension ◽  
Western Blot ◽  
In Vitro Experiments ◽  
Rt Pcr ◽  
P Glycoprotein ◽  
Intestinal Microsomes ◽  
First Pass

Abstract Background Portal hypertension (PH) is the main cause of complications and death in liver cirrhosis. The effect of oral administration of octreotide (OCT), a drug that reduces PH by the constriction of mesenteric arteries, is limited by a remarkable intestinal first-pass elimination. Methods The bile duct ligation (BDL) was used in rats to induce liver cirrhosis with PH to examine the kinetics and molecular factors such as P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cytochrome P450 3A4 (CYP3A4) influencing the intestinal OCT absorption via in situ and in vitro experiments on jejunal segments, transportation experiments on Caco-2 cells and experiments using intestinal microsomes and recombinant human CYP3A4. Moreover, RT-PCR, western blot, and immunohistochemistry were performed. Results Both in situ and in vitro experiments in jejunal segments showed that intestinal OCT absorption in both control and PH rats was largely controlled by P-gp and, to a lesser extent, by MRP2. OCT transport mediated by P-gp and MRP2 was demonstrated on Caco-2 cells. The results of RT-PCR, western blot, and immunohistochemistry suggested that impaired OCT absorption in PH was in part due to the jejunal upregulation of these two transporters. The use of intestinal microsomes and recombinant human CYP3A4 revealed that CYP3A4 metabolized OCT, and its upregulation in PH likely contributed to impaired drug absorption. Conclusions Inhibition of P-gp, MRP2, and CYP3A4 might represent a valid option for decreasing intestinal first-pass effects on orally administered OCT, thereby increasing its bioavailability to alleviate PH in patients with cirrhosis.

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