General Pharmacology

in vitro

Also known as:Test-tube experiment · outside the body

Experiments or studies performed outside a living organism, typically in a controlled laboratory environment such as a test tube or petri dish using cells, tissues, or biological molecules.

In depth

In vitro pharmacology includes receptor-binding and enzyme-inhibition assays (yielding Ki and IC50 values), cell-based functional assays, human liver microsomes or hepatocytes for studying metabolism and CYP inhibition or induction, transporter assays, permeability models such as Caco-2 cell monolayers, and dissolution testing of dosage forms. Regulators use in vitro data to screen for drug–drug interaction potential and, for BCS-based biowaivers, accept comparative dissolution in place of in vivo bioequivalence studies.

In vitro findings need confirmation in vivo, because isolated systems lack whole-body pharmacokinetics, protein binding and homeostatic feedback.

Clinical pearl

An in vitro effect seen only at concentrations far above those reached in patients is rarely clinically relevant; compare IC50 or Ki values with the unbound plasma or tissue concentrations actually achieved.

TRIn Turkish

in vitro

Canlı bir organizma dışında, genellikle laboratuvar ortamında (test tüpü veya petri kabında) hücreler, dokular veya biyolojik moleküller kullanılarak gerçekleştirilen deneyler veya çalışmalar.

Farmakolojide in vitro çalışmalar; reseptör bağlanma ve enzim inhibisyonu testlerini (Ki ve IC50 değerleri), hücre temelli işlevsel testleri, metabolizma ile CYP inhibisyonu veya indüksiyonunun incelendiği insan karaciğer mikrozomlarını veya hepatositlerini, taşıyıcı testlerini, Caco-2 hücre tek katmanı gibi geçirgenlik modellerini ve farmasötik dozaj şekillerinin çözünme testlerini kapsar. Düzenleyici otoriteler in vitro verileri ilaç–ilaç etkileşimi potansiyelini taramada kullanır ve BCS temelli biyomuafiyetlerde in vivo biyoeşdeğerlik çalışmalarının yerine karşılaştırmalı çözünme testlerini kabul eder.

İzole sistemler vücudun bütününe ait farmakokinetiği, protein bağlanmasını ve homeostatik geri bildirimi yansıtmadığından in vitro bulguların in vivo olarak doğrulanması gerekir.

Yalnızca hastalarda ulaşılan düzeylerin çok üzerindeki konsantrasyonlarda görülen bir in vitro etki nadiren klinik önem taşır; IC50 veya Ki değerleri, gerçekte ulaşılan serbest plazma ya da doku konsantrasyonlarıyla karşılaştırılmalıdır.

Diğer adları:Test tüpü deneyi · vücut dışında
Updated 24.09.2026 15 views Educational reference — verify against current sources before clinical use.

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in vivoin vivo

Experiments or studies conducted within a living organism, such as in animals or humans, to observe effects in a complete biological system.

 ex vivoex vivo

Describes experiments on living cells, tissues or fluids removed from an organism and studied outside it under conditions that preserve their function, often after the organism has received a drug (Latin, 'out of the living').

 in silicoin siliko

Experiments or studies performed using computer simulations, modeling, or computational methods to predict biological processes without physical testing.

 Half-Maximal Inhibitory ConcentrationYarı Maksimal İnhibitör Konsantrasyon

The concentration of an inhibitor that reduces a specified biological or biochemical activity (e.g. enzyme activity, ligand binding or cell growth) by 50% under the given assay conditions.

 DissolutionÇözünme (Dissolüsyon)

The process by which a solid drug passes into solution in a solvent such as gastrointestinal fluid; for solid oral dosage forms it is a prerequisite for absorption and often its rate-limiting step.

 Preclinical StudyKlinik Öncesi Çalışma

Laboratory and animal investigation of a drug candidate's pharmacology, pharmacokinetics and toxicity, carried out before first administration to humans to justify and design safe clinical trials.