Iran Pharm.D. End-of-Course Exam key terms

The fraction of an administered dose of unchanged drug that reaches the systemic circulation, expressed as a percentage or decimal, determined by comparing plasma concentration-time data against an intravenous reference standard.

The absence of a significant difference in the rate and extent of absorption between two pharmaceutically equivalent products, typically judged by 90% confidence intervals of AUC and Cmax falling within 80–125%.

Presystemic biotransformation of an orally administered drug by intestinal wall enzymes and the liver before it reaches systemic circulation, reducing oral bioavailability and often generating inactive or active metabolites.

The integral of plasma drug concentration over time after a dose; it reflects total systemic exposure and is used to calculate clearance, bioavailability, and bioequivalence comparisons between products.

The peak plasma concentration observed after a dose, together with the time to reach it (Tmax), describing the rate and intensity of absorption and used in bioequivalence and therapeutic drug monitoring decisions.

The time after administration at which peak plasma concentration occurs; it indicates absorption rate, is shortened by faster-release formulations, and guides timing of sampling and onset-of-effect expectations.

The volume of plasma from which a drug is completely removed per unit time, equal to dose divided by AUC for a given route; it determines the maintenance dose needed to sustain a target steady-state concentration.

A theoretical volume relating the amount of drug in the body to its plasma concentration; large values indicate extensive tissue distribution, and it converts a desired plasma concentration into a loading dose.

The time required for plasma drug concentration to fall by half during first-order elimination; it governs dosing interval selection and the time to reach steady state, roughly four to five half-lives.

The condition in which drug input equals elimination, so plasma concentrations fluctuate within a constant range; reached after about four to five half-lives of regular dosing and the basis for therapeutic drug monitoring sampling.

An initial larger dose given to rapidly achieve a target therapeutic plasma concentration, calculated from volume of distribution and desired concentration, then followed by smaller maintenance doses.

The dose given repeatedly to replace the amount of drug eliminated between administrations, calculated from clearance, target concentration, dosing interval, and bioavailability so that steady state is preserved.

Clinical measurement of plasma drug concentrations for drugs with narrow therapeutic indices or unpredictable kinetics, interpreted alongside timing, adherence, and clinical response to individualize dosing.

A ratio comparing the dose producing toxicity with the dose producing therapeutic effect; a narrow index means small dose changes or concentration shifts can cause treatment failure or serious adverse effects.

A graph relating increasing drug doses or concentrations to graded response magnitude or to the proportion of a population responding, revealing potency, efficacy, slope, and threshold or maximal effects.

The concentration of a drug that produces half of its maximal effect in a graded response system; a lower value indicates higher potency and permits comparison among agents acting on the same receptor.

A ligand that binds a receptor and activates it, producing a conformational change and biological response; full agonists achieve maximal efficacy, while partial agonists produce submaximal responses even at saturation.

A ligand that binds reversibly at the same site as the agonist, preventing agonist binding; it shifts the dose-response curve rightward without lowering maximal response at sufficiently high agonist concentrations.

A ligand that binds a receptor and reduces its constitutive activity below the unliganded baseline, producing effects opposite to an agonist and distinguishing receptor states from simple blockade.

A harmful or unintended response to a medicine occurring at normal therapeutic doses; classified by mechanism and predictability, and a core target of pharmacovigilance reporting and causality assessment.

The science of detecting, assessing, understanding, and preventing adverse effects or other drug-related problems, using spontaneous reports, signal detection, and risk management throughout a product's lifecycle.

Blockade of cytochrome P450 enzyme activity by a co-administered drug, slowing metabolism of substrates and raising their concentrations; a major mechanism of drug-drug interactions and toxicity.

Increased synthesis or activity of drug-metabolizing enzymes after repeated exposure to an inducer, accelerating substrate clearance and potentially causing therapeutic failure or altered prodrug activation.

A pharmacologically inactive derivative that must undergo chemical or enzymatic conversion in the body to release the active drug, often used to improve absorption, stability, or targeting.

The systematic relationship between molecular structural features of a compound and its biological activity, used to guide rational modification of leads toward greater potency, selectivity, and favorable pharmacokinetics.

The spatial arrangement of chemical features in a molecule that is essential for a specific biological activity, serving as a template for designing new active compounds and comparing ligand series.

A chemical group or atom replaced by another with similar size, electronics, or hydrogen-bonding behavior, preserving activity while improving properties such as metabolic stability or solubility.

A prototype molecule with demonstrated biological activity that serves as the starting point for structural optimization, with iterative synthesis and testing guided by structure-activity relationships.

A set of empirical criteria for predicting oral absorption of drug candidates: molecular weight under 500, logP under 5, fewer than 5 hydrogen-bond donors, and fewer than 10 hydrogen-bond acceptors.

The ability of a drug to cross biological membranes, influenced by lipophilicity, ionization, size, and transporter interactions; a key determinant of absorption and tissue distribution in biopharmaceutics.

A membrane protein such as P-glycoprotein that pumps drugs out of cells, limiting intestinal absorption and brain entry or mediating resistance; its inhibition or induction alters drug exposure.

A framework classifying drugs by aqueous solubility and intestinal permeability into four classes, guiding formulation strategy, dissolution specifications, and eligibility for biowaivers of bioequivalence studies.

An in vitro method measuring the rate and extent a solid dosage form releases drug into a specified medium; it supports quality control, batch release, and prediction of in vivo absorption behavior.

A dosage design that releases drug gradually over an extended period, reducing dosing frequency and smoothing plasma fluctuations while risking dose dumping if release is uncontrolled.

Preparation of sterile medicines such as injections or ophthalmic products using aseptic technique, validated facilities, and environmental monitoring to prevent microbial and particulate contamination.

A set of practices performed under controlled conditions to keep preparations and equipment free of microorganisms, including hand hygiene, sterile gloves, disinfection, and working within laminar airflow.

A quality assurance system ensuring medicinal products are consistently produced and controlled according to quality standards, covering premises, personnel, documentation, validation, and batch release.

Documented evidence that a process, method, or system consistently produces results meeting predetermined specifications; required for manufacturing processes, analytical procedures, and computerized systems.

A separation technique in which a liquid mobile phase is pumped through a packed column, resolving mixture components for identification and quantification; the mainstay of pharmaceutical assay and impurity testing.

An analytical technique that ionizes molecules and separates them by mass-to-charge ratio, providing molecular mass and fragmentation data used for structure confirmation, metabolite identification, and bioanalysis.

An official published standard for a drug substance or product specifying identity, assay, purity limits, and test methods, providing the legally recognized basis for quality evaluation and acceptance decisions.

Adjusting a plant preparation to a defined content of one or more marker or active constituents, ensuring batch-to-batch consistency of composition and therapeutic effect.

A chemically defined constituent of a medicinal plant used to identify the material, assess quality, or standardize extracts, even when it is not the principal contributor to activity.

The study of medicinal substances of natural origin, covering botanical identification, cultivation, extraction, chemical constituents, biological activity, and quality control of plant and other natural products.

A naturally occurring nitrogen-containing basic compound found mainly in plants, often pharmacologically potent; examples include morphine, atropine, and quinine, typically extracted after basification.

A plate-based immunoassay using antibody-antigen binding linked to an enzyme reporter for colorimetric detection, widely applied to quantify proteins, hormones, and antibodies in clinical and research laboratories.

The interval of laboratory test values expected in a defined healthy population, used to interpret a patient result as normal or abnormal in light of clinical context and preanalytical variables.

A measurable biological indicator such as a molecule, gene, or imaging feature that reflects a normal process, disease state, or treatment response, used for diagnosis, prognosis, or monitoring.

An identical immunoglobulin produced from a single cloned B-cell line, binding one specific epitope; used therapeutically and diagnostically, with humanization reducing immunogenicity and improving half-life.

A biological product highly similar to an approved reference biologic in structure, efficacy, and safety, licensed after comparability exercises rather than full clinical development, with immunogenicity monitoring required.

The coordinated physiological regulation that keeps internal conditions such as pH, temperature, glucose, and electrolyte concentrations within narrow ranges despite external and internal disturbances.

A control mechanism in which the output of a system suppresses its own production, stabilizing hormone and metabolite levels; its failure produces disorders such as unchecked hormone secretion.

The study of functional changes accompanying disease, linking disturbed physiological mechanisms to clinical signs, symptoms, and the rationale for therapeutic intervention.

A medicinal product sold without a prescription for self-treated minor conditions, subject to approved indications, labeling, pack-size limits, and pharmacist counseling requirements.

Patient-centered practice in which pharmacists accept responsibility for medication-related needs, working to optimize outcomes through counseling, monitoring, adherence support, and detection of drug-related problems.

The extent to which a patient takes medicines as prescribed in timing, dose, and duration; assessed through refill records, pill counts, or questionnaires and improved by simplification and education.

The study of costs and outcomes of pharmaceutical interventions, using methods such as cost-effectiveness and cost-utility analysis to inform formulary, pricing, and reimbursement decisions.

Prescribing and using medicines appropriately to clinical need, at correct doses and durations, at affordable cost; promoted through formularies, treatment guidelines, and prescription auditing.