Medical Sciences 4930F/G Lecture Notes - Lecture 3: Enterocyte, Cyp3A4, Indinavir
17 Apr 2015
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Rate and extend of an oral dose reaching the systemic circulation unchanged. Expressed as a fraction or percent of the oral dose. Contents of the tablet are entering a solution state (dissolving) Key physical property: water solubility (high polarity, aqueous solubility in acid (high polarity, aided by formulating drug as a salt (i. e. diphenhydramine hcl or sulfate) Where are most of the drugs absorbed: small intestine: high surface area, higher blood flow. When is gastric emptying most consistent: drug administration on empty stomach with a cool glass of water. How is this process hindered: water solubility (high polarity) of drug. Problematic because it needs to pass through the lipid membrane of a cell. If it can be made as a sault, it foes from low stomach ph to neutrality: base has lipophillicity and it enables it to diffuse across the membrane. Needs to have a balance in hydrophilic and lipophilic properties: drug metabolism (first-pass first time through liver)
