Bioavailability
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Biologická dostupnost je definována jako rychlost a rozsah, v nichž je léčivá látka absorbována adosáhne místa svého účinku, respektive systémové cirkulace. Míra biologické dostupnosti léčiva po perorálním podání je závislá na celé řadě skutečností, mezi něž je možné zařadit fyzikálně-chemické vlastnosti léčiva, fyziologické aspekty organismu, typ lékové formy, současný příjem potravy, biorytmy aintra- ainterindividuální rozdíly v lidské populaci. Tento článek je prvním ze série zabývající se biologickou dostupností a metodami jejího zlepšování, především u léčiv s nízkou rozpustností ve vodě. Cílem práce je přinést přehled faktorů, které mohou mít vliv na míru biologické dostupnosti léčiva po jeho perorálním podání. Následující články pak nabídnou popis, zde jen souhrnně vyjmenovaných, metod používaných při snaze zlepšit biologickou dostupnost špatně rozpustných účinných látek.
Bioavailability can be defined as the rate and range of active ingredient absorption, when it becomes available in the systemic circulation or at the desired site of drug action, respectively. Drug bioavailability after oral administration is affected by a number of different factors, including physicochemical properties of the drug, physiological aspects, the type of dosage form, food intake, biorhythms, and intra- and interindividual variability of the human population. This article is the first from the series dealing with the bioavailability and methods leading to its improvement. The aim of the present paper is to provide an overview of aspects influencing the rate of bioavailability after oral administration of the active ingredient. Subsequent articles will provide detailed descriptions of methods used for dug bioavailability improvement, which are here only summarized.
WHO technical report series ; no. 536
17 s.
Správná výživa a aktivní životní styl hrají v lidském zdraví zásadní roli. Polyfenolové látky, vyskytující se především v ovoci a zelenině, mohou ovlivňovat řadu onemocnění, a to jak způsobem prevence, tak ve formě léčiv a doplňků stravy. Významným zástupcem polyfenolů, ze skupiny stilbenů, je resveratrol, který je díky svým vlastnostem potencionálním kandidátem na léčivo s vícespektrální terapeutickou aplikací. Tento článek shrnuje poznatky o biologické aktivitě a dostupnosti polyfenolových látek v potravinách se zaměřením na resveratrol. Cílem tohoto přehledu je popis polyfenolových biologicky aktivních látek ve stravě, účincích polyfenolových látek na lidský organismus a také jejich osud v organismu spojený s výzvami biologické dostupnosti, a tedy i jejich aktivitě.
Proper nutrition and active lifestyle play a key role in human health. Polyphenol substances, mainly found in fruits and vegetables, can affect a number of diseases by way of prevention and in the form of medicaments and dietary supplements. An important representative of polyphenols, from the group of stilbenes, is resveratrol. Resveratrol is, due to its properties, a potential drug candidate with multi -spectrum therapeutic application. This article summarizes the knowledge on the bioactivity and bioavailability of polyphenol compounds in food with a major focus on resveratrol. The aim of this review is to describe polyphenol biologically active substances in the diet, the effects of polyphenols on the human body and their fate in the organism associated with the challenges of their bioavailability, thus their biological activity.
- MeSH
- biologická dostupnost * MeSH
- fyziologie výživy MeSH
- klinická studie jako téma MeSH
- lidé MeSH
- ochranné látky metabolismus MeSH
- ovoce MeSH
- resveratrol * metabolismus MeSH
- zdraví MeSH
- zelenina MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
214 s. : il. ; 25 cm
- Klíčová slova
- biodostupnost, farmakodynamika,
- MeSH
- farmakokinetika MeSH
- Konspekt
- Farmacie. Farmakologie
- NLK Publikační typ
- sborníky
PURPOSE OF REVIEW: Oral drug absorption after bariatric surgery is likely to be altered, but the impact of different bariatric surgery procedures on individual drugs is not uniform. The aim of this article is to describe factors influencing the bioavailability of orally administered drugs after bariatric surgery and to provide readers with practical recommendations for drug dosing. We also discuss the medications that may be harmful after bariatric surgery. RECENT FINDINGS: The fundamental factors for enteral drug absorption are the production of gastric acid; the preserved length of the intestine, i.e., the size of the absorption surface and/or the preserved enterohepatic circulation; and the length of common loop where food and drugs are mixed with digestive enzymes and bile acids. Bypassing of metabolizing enzymes or efflux pumps and changes in intestinal motility can also play an important role. Significant changes of drug absorption early after the anatomic alteration may also be gradually ameliorated due to gradual intestinal adaptation. The most affected drugs are those with low or variable bioavailability and those undergoing enterohepatic circulation. Attention should also be paid to oral drug formulations, especially in the early postoperative period, when immediate-release and liquid formulations are preferred. The changes in oral bioavailability are especially clinically meaningful in patients treated with drugs possessing narrow therapeutic index (e.g., oral anticoagulants, levothyroxine, and anticonvulsants) or in acute conditions (e.g., anti-infectives); nevertheless, it may also influence the therapeutic value of chronic therapy (e.g., antidepressants. antihypertensives, antiplatelets, statins, PPIs, contraceptives, and analgesics); therapeutic effect of chronic therapy is further influenced by pharmacokinetic alterations resulting from weight loss. Therapeutic drug monitoring, periodical clinical evaluation, and adequate dose adjustments are necessary. Due to safety reasons, patients should avoid oral bisphosphonates, regular use of non-steroidal anti-inflammatory drugs, and, if possible, corticosteroids after bariatric surgery.
- MeSH
- bariatrická chirurgie * metody MeSH
- biologická dostupnost MeSH
- gastrektomie MeSH
- hmotnostní úbytek MeSH
- lidé MeSH
- morbidní obezita * chirurgie MeSH
- žaludeční bypass * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Stilbenoids are interesting natural compounds with pleiotropic in vitro and in vivo activity. Their well-documented biological properties include anti-inflammatory effects, anticancer effects, effects on longevity, and many others. Therefore, they are nowadays commonly found in foods and dietary supplements, and used as a part of treatment strategy in various types of diseases. Bioactivity of stilbenoids strongly depends on different types of factors such as dosage, food composition, and synergistic effects with other plant secondary metabolites such as polyphenols or vitamins. In this review, we summarize the existing in vitro, in vivo, and clinical data from published studies addressing the optimization of bioavailability of stilbenoids. Stilbenoids face low bioavailability due to their chemical structure. This can be improved by the use of novel drug delivery systems or enhancers, which are discussed in this review. Current in vitro and in vivo evidence suggests that both approaches are very promising and increase the absorption of the original substance by several times. However, data from more clinical trials are required.
- MeSH
- biologická dostupnost MeSH
- lékové transportní systémy MeSH
- lidé MeSH
- potravní doplňky MeSH
- resveratrol chemie farmakokinetika terapeutické užití MeSH
- stilbeny chemie farmakokinetika terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Many new therapeutic candidates and active pharmaceutical ingredients (APIs) are poorly soluble in an aqueous environment, resulting in their reduced bioavailability. A promising way of enhancing the release of an API and, thus, its bioavailability seems to be the use of liquid oil marbles (LOMs). An LOM system behaves as a solid form but consists of an oil droplet in which an already dissolved API is encapsulated by a powder. This study aims to optimize the oil/powder combination for the development of such systems. LOMs were successfully prepared for 15 oil/powder combinations, and the following properties were investigated: particle mass fraction, dissolution time, and mechanical stability. Furthermore, the release of API from both LOMs and LOMs encapsulated into gelatine capsules was studied.
- MeSH
- biologická dostupnost MeSH
- časové faktory MeSH
- farmaceutická chemie MeSH
- nosiče léků chemie MeSH
- oleje chemie MeSH
- prášky, zásypy, pudry MeSH
- příprava léků metody MeSH
- rozpustnost MeSH
- stabilita léku MeSH
- tobolky MeSH
- uvolňování léčiv MeSH
- voda chemie MeSH
- želatina chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The determination of mycotoxins content in food is not sufficient for the prediction of their potential in vivo cytotoxicity because it does not reflect their bioavailability and mutual interactions within complex matrices, which may significantly alter the toxic effects. Moreover, many mycotoxins undergo biotransformation and metabolization during the intestinal absorption process. Biotransformation is predominantly the conversion of mycotoxins meditated by cytochrome P450 and other enzymes. This should transform the toxins to nontoxic metabolites but it may possibly result in unexpectedly high toxicity. Therefore, the verification of biotransformation and bioavailability provides valuable information to correctly interpret occurrence data and biomonitoring results. Among all of the methods available, the in vitro models using monolayer formed by epithelial cells from the human colon (Caco-2 cell) have been extensively used for evaluating the permeability, bioavailability, intestinal transport, and metabolism of toxic and biologically active compounds. Here, the strengths and limitations of both in vivo and in vitro techniques used to determine bioavailability are reviewed, along with current detailed data about biotransformation of mycotoxins. Furthermore, the molecular mechanism of mycotoxin effects is also discussed regarding the disorder of intestinal barrier integrity induced by mycotoxins.
- MeSH
- biologická dostupnost MeSH
- Caco-2 buňky MeSH
- epitelové buňky enzymologie MeSH
- hodnocení rizik MeSH
- intestinální absorpce * MeSH
- lidé MeSH
- metabolická aktivace MeSH
- metabolická inaktivace MeSH
- mykotoxiny metabolismus toxicita MeSH
- permeabilita MeSH
- střevní sliznice enzymologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
