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Chapter 3

Chapter 3

Pharmacokinetics

Pharmacokinetics is a scientific discipline that focuses on the journey of a drug within the body, encompassing four key stages: absorption, distribution, …
Passive transport is a method of drug absorption where small, lipid-soluble drugs can move across the cell membrane. This movement happens along the …
Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their …
The process of oral drug absorption can be influenced by several factors. Weakly acidic drugs tend to be absorbed more readily from the stomach due to …
Bioavailability refers to the proportion of an unaltered drug that, after administration, enters the systemic circulation and can be distributed to the …
When a drug is taken orally, it undergoes a journey starting from the gastrointestinal (GI) tract, passing through the portal vein, reaching the liver, …
Pharmaceutical equivalents, by definition, are drug products with the same active ingredient in the same quantities, encapsulated in identical dosage …
The progression of a drug's impact can be analyzed by examining both the concentration-time course and the effect-time course. The concentration-time …
Upon entering the systemic circulation, drugs can distribute into the interstitial and intracellular fluid of various tissue cells. This distribution is …
Drugs predominantly attach to plasma proteins, with only a small percentage remaining unbound. The unbound portion can be calculated as one minus the …
The single-compartment model serves as a simplified representation of the human body. This model assumes that the body functions as a single, well-mixed …
The two-compartment model divides the body into central and peripheral compartments to account for varying blood perfusion rates among organs and tissues, …
The volume of distribution refers to the theoretical volume necessary to contain the entire amount of an administered drug at the same concentration …
Pharmaceutical substances known as xenobiotics are predominantly lipophilic and nonionized. This enables them to permeate lipid bilayers, such as cell …
A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs …
Phase II reactions are essential for the detoxification and elimination of drugs from the body. These reactions involve the conjugation of parent drugs or …
The kidney serves as the primary organ responsible for eliminating drugs and their metabolites from the body. This process, known as renal elimination, …
During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, …
Once the process of glomerular filtration is completed, blood carrying unfiltered drug molecules traverses through efferent arterioles and makes its way …
Drug elimination refers to removing drugs from the body, either through urine by the kidneys or through bile by the liver. Drug clearance is a …
The liver plays a pivotal role in eliminating drugs and their metabolites, primarily through a process known as biliary excretion. This process involves …
Eliminating drugs from the body is a vital process that occurs through excretion or metabolism. Understanding the kinetics of drug elimination is crucial …
A steady state refers to the level of a drug in the body once it has reached an equilibrium between administration and elimination. It represents the …
A rational dosage regimen considers a drug's pharmacokinetics, including its absorption, distribution, metabolism, and elimination from the body. By …
A drug dosage regimen describes the specific instructions and schedule for administering a drug to a patient. It considers factors such as drug dosage, …
Fixed-dose regimens are a common approach to administer drugs to achieve and maintain desired levels of the drug in the body. In this dosing strategy, a …
Presystemic elimination, or the first-pass effect, is the metabolism of drugs that reduces their effective concentration at the site of action. Apart from …
Physiological barriers are semi-permeable cellular structures restricting drug diffusion into intracellular compartments and tissues. There are six types …
Prodrugs are a class of pharmaceutical compounds that undergo a biotransformation process within the body to be converted into a pharmacologically active …
Sub-micrometer carriers (nanocarriers; NCs) enhance efficacy of drugs by improving solubility, stability, circulation time, targeting, and release. …
The recently introduced microphysiological systems (MPS) cultivating human organoids are expected to perform better than animals in the preclinical tests …
Knowledge of Fe bioavailability is critical to the assessment of the nutritional quality of Fe in foods. In vivo measurement of Fe bioavailability is …