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1.
Curr Opin Gastroenterol ; 40(3): 196-202, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37903075

RESUMO

PURPOSE OF REVIEW: Chronic diarrhea is a common disorder that interferes with normal daily activities and results in poor quality of life. Fecal urgency and incontinence often necessitate clinical consultation, but the pathophysiological mechanisms are difficult to differentiate in a clinical setting. Therefore, drugs targeting the opioid receptors, such as diphenoxylate and loperamide, are typically used, as they reduce both gut motility and secretion. RECENT FINDINGS: For severe diarrhea, morphine-containing extemporaneous opium tincture drops have recently been reprofiled to a pharmaceutical. The drug is indicated for severe diarrhea in adults when other antidiarrheals do not give sufficient fecal emptying control. The pronounced effect is due to the liquid formulation with rapid onset as a drug dissolution step is avoided. A recent prospective, noninterventional study (CLARIFY) of patients treated with opioid drops demonstrates a rapid and sustained therapeutic effect. Tolerance does not develop for the antidiarrheal effect and no dependence was observed after discontinuation. SUMMARY: This mini-review discusses the use of opium derivates for treatment of diarrhea, with an emphasis on opium drops as a new medicinal grade opium for the use as additional treatment of severe diarrhea, emphasizing its mechanism of action and evaluation of the risk-benefit ratio in the clinical setting.


Assuntos
Ópio , Qualidade de Vida , Adulto , Humanos , Ópio/uso terapêutico , Diarreia/tratamento farmacológico , Diarreia/etiologia , Antidiarreicos/uso terapêutico , Loperamida/uso terapêutico , Estudos Observacionais como Assunto
2.
Dig Dis Sci ; 68(5): 1815-1823, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36436156

RESUMO

BACKGROUND: The role of cholinergic receptors in the regulation of duodenal mucosal permeability in vivo is currently not fully described. AIMS: To elucidate the impact of nicotinic and muscarinic acetylcholine receptor signaling in response to luminal hypotonicity (50 mM NaCl) in the proximal small intestine of rat. METHODS: The effect on duodenal blood-to-lumen clearance of 51Cr-EDTA (i.e., mucosal permeability) and motility was studied in the absence and presence of nicotinic and muscarinic receptor agonists and antagonists, a sodium channel blocker (tetrodotoxin), and after bilateral cervical vagotomy. RESULTS: Rats with duodenal contractions responded to luminal hypotonicity by substantial increase in intestinal permeability. This response was absent in animals given a non-selective nicotinic receptor antagonist (mecamylamine) or agonist (epibatidine). Pretreatment with tetrodotoxin reduced the increase in mucosal permeability in response to luminal hypotonicity. Further, the non-selective muscarinic receptor antagonist (atropine) and agonist (bethanechol) reduced the hypotonicity-induced increase in mucosal permeability, while vagotomy was without an effect, suggesting that local enteric reflexes dominate. Finally, neither stimulating nor blocking the α7-nicotinic receptor had any significant effects on duodenal permeability in response to luminal hypotonicity, suggesting that this receptor is not involved in regulation of duodenal permeability. The effect of the different drugs on mucosal permeability was similar to the effect observed for duodenal motility. CONCLUSIONS: A complex enteric intramural excitatory neural reflex involving both nicotinic and muscarinic receptor subtypes mediates an increase in mucosal permeability induced by luminal hypotonicity.


Assuntos
Receptores Colinérgicos , Receptores Nicotínicos , Ratos , Animais , Tetrodotoxina/farmacologia , Duodeno , Permeabilidade
3.
Int J Mol Sci ; 23(6)2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35328333

RESUMO

Intestinal mucosal barrier dysfunction caused by disease and/or chemotherapy lacks an effective treatment, which highlights a strong medical need. Our group has previously demonstrated the potential of melatonin and misoprostol to treat increases in intestinal mucosal permeability induced by 15-min luminal exposure to a surfactant, sodium dodecyl sulfate (SDS). However, it is not known which luminal melatonin and misoprostol concentrations are effective, and whether they are effective for a longer SDS exposure time. The objective of this single-pass intestinal perfusion study in rats was to investigate the concentration-dependent effect of melatonin and misoprostol on an increase in intestinal permeability induced by 60-min luminal SDS exposure. The cytoprotective effect was investigated by evaluating the intestinal clearance of 51Cr-labeled EDTA in response to luminal SDS as well as a histological evaluation of the exposed tissue. Melatonin at both 10 and 100 µM reduced SDS-induced increase in permeability by 50%. Misoprostol at 1 and 10 µM reduced the permeability by 50 and 75%, respectively. Combination of the two drugs at their respective highest concentrations had no additive protective effect. These in vivo results support further investigations of melatonin and misoprostol for oral treatments of a dysfunctional intestinal barrier.


Assuntos
Enteropatias , Melatonina , Misoprostol , Animais , Enteropatias/patologia , Mucosa Intestinal , Intestinos , Melatonina/farmacologia , Misoprostol/farmacologia , Permeabilidade , Ratos
4.
Int J Mol Sci ; 23(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35162944

RESUMO

Chemotherapy causes intestinal mucositis, which includes villous atrophy and altered mucosal barrier function. However, there is an uncertainty regarding how the reduced small-intestinal surface area affects the mucosal permeability of the small marker probe mannitol (MW 188), and how the mucosa responds to luminal irritants after chemotherapy. The aims in this study were to determine (i) the relationship between chemotherapy-induced villus atrophy and the intestinal permeability of mannitol and (ii) how the mucosa regulate this permeability in response to luminal ethanol and sodium dodecyl sulfate (SDS). This was investigated by treating rats with a single intraperitoneal dose of doxorubicin, irinotecan, or 5-fluorouracil. After 72 h, jejunum was single-pass perfused and mannitol permeability determined at baseline and after 15 min luminal exposure to 15% ethanol or 5 mg/mL SDS. Tissue samples for morphological analyses were sampled from the perfused segment. All three chemotherapeutics caused a similar 30% reduction in villus length. Mannitol permeability increased with irinotecan (1.3-fold) and 5-fluorouracil (2.5-fold) and was reduced with doxorubicin (0.5-fold), suggesting that it is not epithelial surface area alone that regulates intestinal permeability to mannitol. There was no additional increase in mannitol permeability induced by luminal ethanol or SDS in the chemotherapy-treated rats compared to controls, which may be related to the relatively high basal permeability of mannitol compared to other common low-permeability probes. We therefore suggest that future studies should focus on elucidating the complex interplay between chemotherapy in combination with luminal irritants on the intestinal permeability of other probes.


Assuntos
Doxiciclina/efeitos adversos , Fluoruracila/efeitos adversos , Mucosa Intestinal/efeitos dos fármacos , Irinotecano/efeitos adversos , Irritantes/efeitos adversos , Manitol/metabolismo , Mucosite/patologia , Animais , Etanol/efeitos adversos , Injeções Intraperitoneais , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Mucosite/induzido quimicamente , Mucosite/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Permeabilidade , Ratos , Dodecilsulfato de Sódio/efeitos adversos
5.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639101

RESUMO

A well-functional intestinal mucosal barrier can be compromised as a result of various diseases, chemotherapy, radiation, and chemical exposures including surfactants. Currently, there are no approved drugs targeting a dysfunctional intestinal barrier, which emphasizes a significant medical need. One candidate drug reported to regulate intestinal mucosal permeability is melatonin. However, it is still unclear if its effect is primarily receptor mediated or antioxidative, and if it is associated with enteric neural pathways. The aim of this rat intestinal perfusion study was to investigate the mechanisms of melatonin and nicotinic acetylcholine receptors on the increase in intestinal mucosal clearance of 51Cr-labeled ethylenediaminetetraacetate induced by 15 min luminal exposure to the anionic surfactant, sodium dodecyl sulfate. Our results show that melatonin abolished the surfactant-induced increase in intestinal permeability and that this effect was inhibited by luzindole, a melatonin receptor antagonist. In addition, mecamylamine, an antagonist of nicotinic acetylcholine receptors, reduced the surfactant-induced increase in mucosal permeability, using a signaling pathway not influenced by melatonin receptor activation. In conclusion, our results support melatonin as a potentially potent candidate for the oral treatment of a compromised intestinal mucosal barrier, and that its protective effect is primarily receptor-mediated.


Assuntos
Permeabilidade da Membrana Celular , Mucosa Intestinal/efeitos dos fármacos , Doenças do Jejuno/prevenção & controle , Jejuno/efeitos dos fármacos , Melatonina/farmacologia , Receptores de Melatonina/metabolismo , Tensoativos/toxicidade , Animais , Antioxidantes/farmacologia , Motilidade Gastrointestinal , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Doenças do Jejuno/induzido quimicamente , Doenças do Jejuno/metabolismo , Doenças do Jejuno/patologia , Jejuno/metabolismo , Jejuno/patologia , Masculino , Ratos , Ratos Wistar , Receptores de Melatonina/genética , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo
6.
Int J Mol Sci ; 21(18)2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32942716

RESUMO

A healthy intestinal barrier prevents uptake of allergens and toxins, whereas intestinal permeability increases following chemotherapy and in many gastrointestinal and systemic diseases and disorders. Currently, there are no approved drugs that target and repair the intestinal epithelial barrier while there is a medical need for such treatment in gastrointestinal and related conditions. The objective of this single-pass intestinal perfusion study in rats was to investigate the preventive cytoprotective effect of three mucosal protective drugs-melatonin, misoprostol, and teduglutide-with different mechanisms of action on an acute jejunal injury induced by exposing the intestine for 15 min to the anionic surfactant, sodium dodecyl sulfate (SDS). The effect was evaluated by monitoring intestinal clearance of 51Cr-labeled ethylenediaminetetraacetate and intestinal histology before, during, and after luminal exposure to SDS. Our results showed that separate pharmacological pretreatments with luminal misoprostol and melatonin reduced acute SDS-induced intestinal injury by 47% and 58%, respectively, while their use in combination abolished this injury. This data supports further development of drug combinations for oral treatments of conditions and disorders related to a dysregulated or compromised mucosal epithelial barrier.


Assuntos
Enteropatias/tratamento farmacológico , Mucosa Intestinal/efeitos dos fármacos , Melatonina/farmacologia , Misoprostol/farmacologia , Animais , Combinação de Medicamentos , Ácido Edético/farmacologia , Enteropatias/induzido quimicamente , Intestinos/efeitos dos fármacos , Masculino , Perfusão/métodos , Permeabilidade/efeitos dos fármacos , Fenobarbital/farmacologia , Ratos , Ratos Wistar , Dodecilsulfato de Sódio/farmacologia
7.
Molecules ; 25(12)2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32575828

RESUMO

Increased understanding of cancer biology, pharmacology and drug delivery has provided a new framework for drug discovery and product development that relies on the unique expression of specific macromolecules (i.e., antigens) on the surface of tumour cells. This has enabled the development of anti-cancer treatments that combine the selectivity of antibodies with the efficacy of highly potent chemotherapeutic small molecules, called antibody-drug conjugates (ADCs). ADCs are composed of a cytotoxic drug covalently linked to an antibody which then selectively binds to a highly expressed antigen on a cancer cell; the conjugate is then internalized by the cell where it releases the potent cytotoxic drug and efficiently kills the tumour cell. There are, however, many challenges in the development of ADCs, mainly around optimizing the therapeutic/safety benefits. These challenges are discussed in this review; they include issues with the plasma stability and half-life of the ADC, its transport from blood into and distribution throughout the tumour compartment, cancer cell antigen expression and the ADC binding affinity to the target antigen, the cell internalization process, cleaving of the cytotoxic drug from the ADC, and the cytotoxic effect of the drug on the target cells. Finally, we present a summary of some of the experimental ADC strategies used in the treatment of hepatocellular carcinoma, from the recent literature.


Assuntos
Anticorpos Monoclonais/imunologia , Carcinoma Hepatocelular/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Imunoconjugados/química , Neoplasias Hepáticas/tratamento farmacológico , Anticorpos Monoclonais/química , Liberação Controlada de Fármacos , Humanos , Imunoconjugados/imunologia , Simulação de Acoplamento Molecular
8.
Glob Chang Biol ; 23(5): 1832-1846, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27633847

RESUMO

Two fundamental issues in ecology are understanding what influences the distribution and abundance of organisms through space and time. While it is well established that broad-scale patterns of abiotic and biotic conditions affect organisms' distributions and population fluctuations, discrete events may be important drivers of space use, survival, and persistence. These discrete extreme climatic events can constrain populations and space use at fine scales beyond that which is typically measured in ecological studies. Recently, a growing body of literature has identified thermal stress as a potential mechanism in determining space use and survival. We sought to determine how ambient temperature at fine temporal scales affected survival and space use for a ground-nesting quail species (Colinus virginianus; northern bobwhite). We modeled space use across an ambient temperature gradient (ranging from -20 to 38 °C) through a maxent algorithm. We also used Andersen-Gill proportional hazard models to assess the influence of ambient temperature-related variables on survival through time. Estimated available useable space ranged from 18.6% to 57.1% of the landscape depending on ambient temperature. The lowest and highest ambient temperature categories (<-15 °C and >35 °C, respectively) were associated with the least amount of estimated useable space (18.6% and 24.6%, respectively). Range overlap analysis indicated dissimilarity in areas where Colinus virginianus were restricted during times of thermal extremes (range overlap = 0.38). This suggests that habitat under a given condition is not necessarily a habitat under alternative conditions. Further, we found survival was most influenced by weekly minimum ambient temperatures. Our results demonstrate that ecological constraints can occur along a thermal gradient and that understanding the effects of these discrete events and how they change over time may be more important to conservation of organisms than are average and broad-scale conditions as typically measured in ecological studies.


Assuntos
Aves , Comportamento de Nidação , Animais , Ecossistema , Dinâmica Populacional , Temperatura
9.
Mol Pharm ; 14(12): 4252-4261, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-28920690

RESUMO

Currently, the screening of new drug candidates for intestinal permeation is typically based on in vitro models which give no information regarding regional differences along the gut. When evaluation of intestinal permeability by region is undertaken, two preclinical rat models are commonly used, the Ussing chamber method and single-pass intestinal perfusion (SPIP). To investigate the robustness of in vivo predictions of human intestinal permeability, a set of four model compounds was systematically investigated in both these models, using tissue specimens and segments from the jejunum, ileum, and colon of rats from the same genetic strain. The influence of luminal pH was also determined at two pH levels. Ketoprofen had high and enalaprilat had low effective (Peff) and apparent (Papp) permeability in all three regions and at both pH levels. Metoprolol had high Peff in all regions and at both pHs and high Papp at both pHs and in all regions except the jejunum, where Papp was low. Atenolol had low Peff in all regions and at both pHs, but had high Papp at pH 6.5 and low Papp at pH 7.4. There were good correlations between these rat in situ Peff (SPIP) and human in vivo Peff determined previously for the same compounds by both intestinal perfusion of the jejunum and regional intestinal dosing. The results of this study indicate that both investigated models are suitable for determining the regional permeability of the intestine; however, the SPIP model seems to be the more robust and accurate regional permeability model.


Assuntos
Absorção Fisiológica , Avaliação Pré-Clínica de Medicamentos/métodos , Absorção Intestinal/fisiologia , Modelos Animais , Ratos , Animais , Biofarmácia/métodos , Colo/metabolismo , Concentração de Íons de Hidrogênio , Íleo/metabolismo , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Masculino , Perfusão/métodos , Permeabilidade , Ratos Wistar
10.
Mol Pharm ; 14(12): 4233-4242, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-28737398

RESUMO

Over recent decades there has been an increase in the proportion of BCS class II and IV drug candidates in industrial drug development. To overcome the biopharmaceutical challenges associated with the less favorable properties of solubility and/or intestinal permeation of these substances, the development of formulations containing nanosuspensions of the drugs has been suggested. The intestinal absorption of aprepitant from two nanosuspensions (20 µM and 200 µM total concentrations) in phosphate buffer, one nanosuspension (200 µM) in fasted-state simulated intestinal fluid (FaSSIF), and one solution (20 µM) in FaSSIF was investigated in the rat single-pass intestinal perfusion model. The disappearance flux from the lumen (Jdisapp) was faster for formulations containing a total concentration of aprepitant of 200 µM than for those containing 20 µM, but was unaffected by the presence of vesicles. The flux into the systemic circulation (Japp) and, subsequently, the effective diffusion constant (Deff) were calculated using the plasma concentrations. Japp was, like Jdisapp, faster for the formulations containing higher total concentrations of aprepitant, but was also faster for those containing vesicles (ratios of 2 and 1.5). This suggests that aprepitant is retained in the lumen when presented as nanoparticles in the absence of vesicles. In conclusion, increased numbers of nanoparticles and the presence of vesicles increased the rate of transport and availability of aprepitant in plasma. This effect can be attributed to an increased rate of mass transport through the aqueous boundary layer (ABL) adjacent to the gut wall.


Assuntos
Antieméticos/farmacocinética , Absorção Intestinal , Mucosa Intestinal/metabolismo , Morfolinas/farmacocinética , Animais , Antieméticos/química , Aprepitanto , Disponibilidade Biológica , Biofarmácia/métodos , Química Farmacêutica , Masculino , Modelos Animais , Morfolinas/química , Nanopartículas/química , Perfusão/métodos , Ratos , Ratos Wistar , Solubilidade , Suspensões
11.
Mol Pharm ; 14(12): 4243-4251, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-28737406

RESUMO

There is a renewed interest from the pharmaceutical field to develop oral formulations of compounds, such as peptides, oligonucleotides, and polar drugs. However, these often suffer from insufficient absorption across the intestinal mucosal barrier. One approach to circumvent this problem is the use of absorption modifying excipient(s) (AME). This study determined the absorption enhancing effect of four AMEs (sodium dodecyl sulfate, caprate, chitosan, N-acetylcysteine) on five model compounds in a rat jejunal perfusion model. The aim was to correlate the model compound absorption to the blood-to-lumen clearance of the mucosal marker for barrier integrity, 51Cr-EDTA. Sodium dodecyl sulfate and chitosan increased the absorption of the low permeation compounds but had no effect on the high permeation compound, ketoprofen. Caprate and N-acetylcysteine did not affect the absorption of any of the model compounds. The increase in absorption of the model compounds was highly correlated to an increased blood-to-lumen clearance of 51Cr-EDTA, independent of the AME. Thus, 51Cr-EDTA could be used as a general, sensitive, and validated marker molecule for absorption enhancement when developing novel formulations.


Assuntos
Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Excipientes/farmacologia , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Animais , Disponibilidade Biológica , Biofarmácia/métodos , Radioisótopos de Cromo/química , Composição de Medicamentos/métodos , Ácido Edético/química , Mucosa Intestinal/metabolismo , Masculino , Modelos Animais , Perfusão , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Wistar , Dodecilsulfato de Sódio
12.
Drug Dev Ind Pharm ; 43(2): 338-346, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27762631

RESUMO

CONTEXT: Prediction of the in vivo absorption of poorly soluble drugs may require simultaneous dissolution/permeation experiments. In vivo predictive media have been modified for permeation experiments with Caco-2 cells, but not for excised rat intestinal segments. OBJECTIVE: The present study aimed at improving the setup of dissolution/permeation experiments with excised rat intestinal segments by assessing suitable donor and receiver media. METHODS: The regional compatibility of rat intestine in Ussing chambers with modified Fasted and Fed State Simulated Intestinal Fluids (Fa/FeSSIFmod) as donor media was evaluated via several parameters that reflect the viability of the excised intestinal segments. Receiver media that establish sink conditions were investigated for their foaming potential and toxicity. Dissolution/permeation experiments with the optimized conditions were then tested for two particle sizes of the BCS class II drug aprepitant. RESULTS: Fa/FeSSIFmod were toxic for excised rat ileal sheets but not duodenal sheets, the compatibility with jejunal segments depended on the bile salt concentration. A non-foaming receiver medium containing bovine serum albumin (BSA) and Antifoam B was nontoxic. With these conditions, the permeation of nanosized aprepitant was higher than of the unmilled drug formulations. DISCUSSION: The compatibility of Fa/FeSSIFmod depends on the excised intestinal region. The chosen conditions enable dissolution/permeation experiments with excised rat duodenal segments. The experiments correctly predicted the superior permeation of nanosized over unmilled aprepitant that is observed in vivo. CONCLUSION: The optimized setup uses FaSSIFmod as donor medium, excised rat duodenal sheets as permeation membrane and a receiver medium containing BSA and Antifoam B.


Assuntos
Ácidos e Sais Biliares/química , Células CACO-2/fisiologia , Permeabilidade da Membrana Celular/fisiologia , Intestinos/fisiologia , Jejuno/fisiologia , Solubilidade , Animais , Células CACO-2/química , Humanos , Intestinos/química , Jejuno/química , Ratos
13.
Mol Pharm ; 13(9): 3013-21, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27504798

RESUMO

Currently there are only a limited number of determinations of human Peff in the distal small intestine and none in the large intestine. This has hindered the validation of preclinical models with regard to absorption in the distal parts of the intestinal tract, which can be substantial for BCS class II-IV drugs, and drugs formulated into modified-release (MR) dosage forms. To meet this demand, three model drugs (atenolol, metoprolol, and ketoprofen) were dosed in solution intravenously, and into the jejunum, ileum, and colon of 14 healthy volunteers. The Peff of each model drug was then calculated using a validated deconvolution method. The median Peff of atenolol in the jejunum, ileum, and colon was 0.45, 0.15, and 0.013 × 10(-4) cm/s, respectively. The corresponding values for metoprolol were 1.72, 0.72, and 1.30 × 10(-4) cm/s, and for ketoprofen 8.85, 6.53, and 3.37 × 10(-4) cm/s, respectively. This is the first study where the human Peff of model drugs has been determined in all parts of the human intestinal tract in the same subjects. The jejunal values were similar to directly determined values using intestinal single-pass perfusion, indicating that the deconvolution method is a valid approach for determining regional Peff. The values from this study will be highly useful in the validation of preclinical regional absorption models and in silico tools.


Assuntos
Absorção Intestinal/fisiologia , Mucosa Intestinal/metabolismo , Adolescente , Adulto , Atenolol/metabolismo , Atenolol/farmacocinética , Colo/metabolismo , Feminino , Humanos , Íleo/metabolismo , Intestino Delgado/metabolismo , Jejuno/metabolismo , Cetoprofeno/metabolismo , Cetoprofeno/farmacocinética , Masculino , Metoprolol/metabolismo , Metoprolol/farmacocinética , Pessoa de Meia-Idade , Permeabilidade , Adulto Jovem
14.
Mol Pharm ; 13(9): 3022-33, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27500599

RESUMO

The development of oral modified-release (MR) dosage forms requires an active pharmaceutical ingredient (API) with a sufficiently high absorption rate in both the small and large intestine. Dogs are commonly used in preclinical evaluation of regional intestinal absorption and in the development of novel MR dosage forms. This study determined regional intestinal effective permeability (Peff) in dogs with the aim to improve regional Peff prediction in humans. Four model drugs, atenolol, enalaprilat, metoprolol, and ketoprofen, were intravenously and regionally dosed twice as a solution into the proximal small intestine (P-SI) and large intestine (LI) of three dogs with intestinal stomas. Based on plasma data from two separate study occasions for each dog, regional Peff values were calculated using a validated intestinal deconvolution method. The determined mean Peff values were 0.62, 0.14, 1.06, and 3.66 × 10(-4) cm/s in the P-SI, and 0.13, 0.02, 1.03, and 2.20 × 10(-4) cm/s in the LI, for atenolol, enalaprilat, metoprolol, and ketoprofen, respectively. The determined P-SI Peff values in dog were highly correlated (R(2) = 0.98) to the historically directly determined human jejunal Peff after a single-pass perfusion. The determined dog P-SI Peff values were also successfully implemented in GI-Sim to predict the risk for overestimation of LI absorption of low permeability drugs. We conclude that the dog intestinal stoma model is a useful preclinical tool for determination of regional intestinal permeability. Still, further studies are recommended to evaluate additional APIs, sources of variability, and formulation types, for more accurate determination of the dog model in the drug development process.


Assuntos
Intestino Grosso/metabolismo , Intestino Delgado/metabolismo , Animais , Atenolol/farmacocinética , Cães , Enalaprilato/farmacocinética , Humanos , Absorção Intestinal , Jejuno/metabolismo , Cetoprofeno/farmacocinética , Masculino , Metoprolol/farmacocinética , Permeabilidade
15.
Mol Pharm ; 12(6): 2026-39, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25919764

RESUMO

Application of information on regional intestinal permeability has been identified as a key aspect of successful pharmaceutical product development. This study presents the results and evaluation of an approach for the indirect estimation of site-specific in vivo intestinal effective permeability (Peff) in humans. Plasma concentration-time profiles from 15 clinical studies that administered drug solutions to specific intestinal regions were collected and analyzed. The intestinal absorption rate for each drug was acquired by deconvolution, using historical intravenous data as reference, and used with the intestinal surface area and the dose remaining in the lumen to estimate the Peff. Forty-three new Peff values were estimated (15 from the proximal small intestine, 11 from the distal small intestine, and 17 from the large intestine) for 14 active pharmaceutical ingredients representing a wide range of biopharmaceutical properties. A good correlation (r(2) = 0.96, slope = 1.24, intercept = 0.030) was established between these indirect jejunal Peff estimates and jejunal Peff measurements determined directly using the single-pass perfusion double balloon technique. On average, Peff estimates from the distal small intestine and large intestine were 90% and 40%, respectively, of those from the proximal small intestine. These results support the use of the evaluated deconvolution method for indirectly estimating regional intestinal Peff in humans. This study presents the first comprehensive data set of estimated human regional intestinal permeability values for a range of drugs. These biopharmaceutical data can be used to improve the accuracy of gastrointestinal absorption predictions used in drug development decision-making.


Assuntos
Mucosa Intestinal/metabolismo , Budesonida/farmacocinética , Colo/citologia , Ciclosporina/farmacocinética , Fenofibrato/análogos & derivados , Fenofibrato/farmacocinética , Humanos , Absorção Intestinal , Dimesilato de Lisdexanfetamina/farmacocinética , Metoprolol/farmacocinética , Nifedipino/farmacocinética , Pirimidinas/farmacocinética , Ranitidina/farmacocinética , Rivastigmina/farmacocinética , Sumatriptana/farmacocinética , Terfenadina/análogos & derivados , Terfenadina/farmacocinética , Teofilina/farmacocinética
16.
J Pharm Biomed Anal ; 249: 116348, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38996751

RESUMO

Chemically induced, targeted protein degradation with proteolysis targeting chimeras (PROTACs) has shown to be a promising pharmacological strategy to circumvent the poor "druggability" of intracellular targets. However, the favorable pharmacology comes with complex molecular properties limiting the oral bioavailability of these drugs. To foster the translation of PROTACs into the clinics it is of high importance to establish sensitive bioanalytical methods that enable the assessment of absorption, bioavailability, and disposition of PROTACs after oral dosing. In this study, two highly sensitive LC-MS/MS methods (LLOQ = 0.5 ng/mL) were developed and validated for the quantification of bavdeglutamide (ARV-110) and vepdegestrant (ARV-471) in rat plasma. Plasma samples were processed by protein precipitation and separated on a C18 column over a gradient of acetonitrile and water with 0.1 % formic acid. Selected reaction monitoring in positive ESI mode was applied to quantify ARV-110 and ARV-471. Both methods showed linearity, accuracy, and precision as well as matrix effects and carry-over within the predefined acceptance criteria. High stability of the compounds in plasma was demonstrated at long-term storage for seven weeks at -20 °C, three freeze-thaw cycles, up to 20 min at room temperature, and as extracts in the autosampler. The plasma concentration-time curves after intravenous and intraduodenal bolus single-dose administrations in rats could be successfully quantified at clinically relevant doses per body weight. The highly sensitive bioanalytical assays presented in this work enable the application of a broad spectrum of in vivo studies to elucidate the oral absorption, bioavailability, and disposition of PROTACs.

17.
Biomed Pharmacother ; 162: 114644, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37018992

RESUMO

Chemotherapy kills fast-growing cells including gut stem cells. This affects all components of the physical and functional intestinal barrier, i.e., the mucus layer, epithelium, and immune system. This results in an altered intestinal permeability of toxic compounds (e.g., endotoxins) as well as luminal bacterial translocation into the mucosa and central circulation. However, there is uncertainty regarding the relative contributions of the different barrier components for the development of chemotherapy-induced gut toxicity. This review present an overview of the intestinal mucosal barrier determined with various types of molecular probes and methods, and how they are affected by chemotherapy based on reported rodent and human data. We conclude that there is overwhelming evidence that chemotherapy increases bacterial translocation, and that it affects the mucosal barrier by rendering the mucosa more permeable to large permeability probes. Chemotherapy also seems to impede the intestinal mucus barrier, even though this has been less clearly evaluated from a functional standpoint but certainly plays a role in bacteria translocation. Combined, it is however difficult to outline a clear temporal or succession between the different gastrointestinal events and barrier functions, especially as chemotherapy-induced neutropenia is also involved in intestinal immunological homeostasis and bacterial translocation. A thorough characterization of this would need to include a time dependent development of neutropenia, intestinal permeability, and bacterial translocation, ideally after a range of chemotherapeutics and dosing regimens.


Assuntos
Antineoplásicos , Neutropenia , Humanos , Translocação Bacteriana , Mucosa Intestinal/microbiologia , Permeabilidade , Muco
18.
Basic Clin Pharmacol Toxicol ; 132(6): 511-520, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36878867

RESUMO

Chemotherapy-induced mucositis, characterized by diarrhoea and villous atrophy, is a severe side effect contributing to reduced quality of life and premature death in cancer patients treated with cytostatics. Despite its high incidence, there is no effective supportive therapy available. The main objective of this study was to determine if the anti-inflammatory drugs anakinra and/or dexamethasone-which have different mechanisms-of-action-might be used to effectively treat idarubicin-induced mucositis in rats. Mucositis was induced through a single injection with 2 mg/kg idarubicin (with saline as control), followed by daily treatments of anakinra (100 mg/kg/day), dexamethasone (10 mg/kg/day) or both for 3 days. After 72 h, jejunal tissue was collected for morphological, apoptotic and proliferative analyses, and colonic faecal water content and body weight change were determined. The diarrhoea that was induced by idarubicin (from 63.5% to 78.6% water content in faeces) was completely reversed by anakinra alone, and the jejunal villus height reduction by 36% was prevented by a combination of anakinra and dexamethasone. Dexamethasone reduced apoptosis in the jejunal crypts, both alone and in combination with anakinra. These positive effects encouraged further investigations into the use of anakinra and dexamethasone as supportive therapies for chemotherapy-induced intestinal mucositis and diarrhoea.


Assuntos
Antineoplásicos , Mucosite , Ratos , Animais , Mucosite/induzido quimicamente , Mucosite/tratamento farmacológico , Mucosite/prevenção & controle , Proteína Antagonista do Receptor de Interleucina 1/efeitos adversos , Idarubicina/efeitos adversos , Qualidade de Vida , Diarreia/induzido quimicamente , Diarreia/tratamento farmacológico , Antineoplásicos/farmacologia , Dexametasona/farmacologia , Mucosa Intestinal , Fluoruracila/efeitos adversos
19.
JMIR Res Protoc ; 12: e47568, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37428548

RESUMO

BACKGROUND: Many factors influence housing choices among older adults, but far from all have been identified. There is little systematic analysis that has included economic factors and virtually no knowledge about the interplay among perceived costs of moving, health status, and the mobility rate of older homeowners. It is currently unclear whether economic factors influence older adults' willingness to move, and the effects of economic policies on their actual behavior in the housing market are largely unknown. OBJECTIVE: The overarching objective of the AGE-HERE project is to develop knowledge of the relationship between health and economic factors that incentivize or disincentivize relocation during the process of aging. METHODS: This project uses a mixed methods convergent design across 4 studies. The initial quantitative register study and subsequent qualitative focus group study will nurture the evidence base and the development of a national survey. The final study will synthesize and integrate the results of the entire project. RESULTS: Ethical approval for the register study (DNR 2022-04626-01) and focus group study (DNR 2023-01887-01) has been obtained. As of July 2023, data analyses (register study) and data collection (focus group study) are currently being conducted. The first paper based on the register data is expected to be submitted after the summer of 2023. Three meetings have been held with the nonacademic reference group. The qualitative data will be analyzed in the autumn. Based on the results of these studies, a survey questionnaire will be developed and distributed nationally during the spring of 2024, followed by data analyses in the autumn. Finally, the results from all studies will be synthesized in 2025. CONCLUSIONS: Results from AGE-HERE will add to the knowledge base for research on aging, health, and housing and can play a critical role in guiding future policy decisions aiming to balance the housing market. Such developments may lower related social costs and support older adults to maintain active, independent, and healthy lives. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/47568.

20.
Pharmaceutics ; 15(10)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37896157

RESUMO

Drug permeation across the intestinal epithelium is a prerequisite for successful oral drug delivery. The increased interest in oral administration of peptides, as well as poorly soluble and poorly permeable compounds such as drugs for targeted protein degradation, have made permeability a key parameter in oral drug product development. This review describes the various in vitro, in silico and in vivo methodologies that are applied to determine drug permeability in the human gastrointestinal tract and identifies how they are applied in the different stages of drug development. The various methods used to predict, estimate or measure permeability values, ranging from in silico and in vitro methods all the way to studies in animals and humans, are discussed with regard to their advantages, limitations and applications. A special focus is put on novel techniques such as computational approaches, gut-on-chip models and human tissue-based models, where significant progress has been made in the last few years. In addition, the impact of permeability estimations on PK predictions in PBPK modeling, the degree to which excipients can affect drug permeability in clinical studies and the requirements for colonic drug absorption are addressed.

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