Basic Concepts - Terminology Flashcards
Process of uptake of the compound from the site of administration into systemic circulation
Absorption
Extent or fraction of drug absorbed upon extravascular administration in comparison to the dose size administered
Absolute bioavailability
A prerequisite for absorption
Drug must be in aqueous solution
Rate of constant of the entire process of drug transfer into the body, through all biological membrane
Absorption rate constant
Increase of drug concentration in blood and tissue upon multiple dosing until steady state is reached
Accumulation
Ratio of the concentration at equilibrium between a lipid phase (usually octanol) and an aqueous phase (buffer 7.4)
Apparent partition coefficient
Uncorrected for dissociation or association in either phase
Apparent partition coefficient
Integral of drug blood level over time from zero to infinity
Area under the curve
Measure of quantity of drug absorbed and in the body
Area under the curve
Phenomenon that the drug is emptied via bile to the small intestine can be reabsorbed from the intestinal lumen into systemic circulation
Biliary recycling or Enterohepatic Recirculation
Rate and extent to which an active drug substance or moiety is absorbed from the pharmaceutical dosage form and becomes available at its site of action
Bioavailability
Extent and rate of absorption are not statistically different from those of the standard when administered at the same molar dose
Bioequivalence
Requirement imposed by the FDA for in vitro and or invivo testing of specified drug product which must be satisfied as a condition of marketing
Bioequivalence Requirement
Deals with physical and chemical properties of the drug substance, the dosage form and the body and the biological effectiveness of a drug or drug products upon administration
(ex drug availability to the human or animal body from a given dosage form)
Biopharmaceutics
Considered as a drug delivery system
Biopharmaceutics
Actual site of action of a drug in the body
Biophase
Drug-receptor interaction on the molecular level or the effect of the presence of a drug on biopolymers
Biophase
Maybe the surface of a cell or within the cell
Biophase
Speed of blood perfusion in an organ, usually expressed in mL/100 g organ wt/min
Blood flow rate
May differ several-fold between rest and exercise
Blood flow rate
Concentration in blood, plasma, or serum upon administration of a dosage form by various routes of administration
Blood, plasma, or serum levels
Plots of drug concentration versus time on numeric or semilog graph paper
Blood, plasma, or serum level curves
Obtained from blood samples by venipuncture in certain time intervals after administration of the drug product and chemical or microbiological analysis of the drug in the biological fluid
Blood, plasma, or serum levels
Sum of all body regions (organs and tissue) in which the drug concentration is in instantaneous equilibrium with that in blood or plasma
Central compartment
Always a part of the central compartment
Blood and plasma
Hypothetical volume of distribution in mL of the unmetabolized drug which is cleared per unit of time (mL/min or mL/h) by any pathway of drug removal
Clearance
Entity which can be described by a definite volume and a concentration of drug contained in that volume
Compartment
Difference in the concentration in two phases usually separated by a membrane
Concentration gradient
Plots of the actual cumulative amouts of drug and/or its metabolites excreted into irine versus time upon administration of a drug product by various routes of administration
Cumulative urinary excretion curves
Portion of a prolonged release dosage form which liberates the drug from the dosage form at a slower rate than its unrestricted absorption rate
Depot phase
Viscous layer of concentrated drug solution around a dissolving particle
Diffusion layer
Loss of drug from the central compartment due to distribution into other compartments and or elimination
Disposition
Systematized dosage schedule for therapy
Dosage regimen or dose rate
Ex. The proper dose sizes and proper dosing intervals required to produce clinical effectiveness or to maintain a therapeutic concentration in the body
Dosage regimen or dose rate
A change of one or more of the pharmacokinetic process of absorption, distribution, metabolism and excretion with increasing dose size
Dose dependency
Describe the achievement of sustained drug concentration by simply increasing the dose size or by accidental fast release drug from sustained release dosage form
Dose dumping
Amount of drug in microgram, mg units
Dose size
Time period bet administration of maintenance dose
Dosing interval
Chemical compound of synthetic, semisynthetic, natural, or biological origin which interacts with human or animal cells
Drug
Pharmacologically active compounds undergoing evaluation of their potential as future drug substance
Drug candidates
Gross pharmaceutical form containing the API and vehicle substances necessary in formulating a medicament of desired dosage, desired volume and desired application form, ready for administration
Drug product or dosage form
Delivery of the active ingredient from a dosage form into solution.
Drug release or liberation
Dissolution medium is either a biological fluid or an artificial fluid
Drug release or liberation
Characterized by speed and the amount of drug appearing in solution
Drug release or liberation
Drug product usually of unvarying composition, labeled with a registered trademark of a company
Drug specialty or brand product
Active ingredients within a dosage form
Drug substances
Time in hoursu necessary to reduce the drug concentration in the blood, plasma , serum to one-half after equilibrium is reached
Elimination half-life
Increase in enzyme content or rate of enzymatic processes resulting in faster metabolism of a compound
Enzyme induction
Decrease in rate of metabolism of a compound usually by competition for an enzyme system
Enzyme inhibition
Final elimination from the body’s systemic circulatioon via the kidney into urine, via bile and saliva into intestines and into feces, via sweat, via skin and via milk
Excretion
All routes of administration exept those where the drug is directly introduced into the blood stream.
Example are IM, SC, PO, ORAL, RECTAL, IP, TOPICAL
Extravascular administration
Graphical method for the separation of exponents such as separating the absorption rate constant from the elimination rate constant
Feathering
Synonymous with residual method
Feathering
Phenomenon whereby drugs may be metabolized following absorption but before reaching the systemic circulation
First pass effect
May occur following PO and deep rectal administration
First pass effect
May be avoided by using sublingual and buccal routes of administration
First pass effect
Drug marketed under the nonproprietary or common name of the drug
Generic product
Hypothetical volume of distribution in mL of the unmetabolized drug which is cleared in one minute via liver
Hepatic clearance
Portion of a prolonged release dosage form which is immediately availabke for absorption
Initial phase
Refers to all routes of administration where the drug is directly introduced in the blood stream
Ex, IV, IA, IC
Its BA is 100%
Intravascular administration
Physiologic nonsense and poor use of language
Correct term is IV Push
IV Bolus
Deals with complex dynamic processes of liberation of an active ingredient from the dosage form, its absorption into systemic circulation, its distribution and metabolism in the body and excretion of the drug from the body and achievement of response
LADMER SYSTEM
Period of time which elapses bet the time of administration and the time a measurable drug concentration is found in the blood
Lag time
Often found upon PO administration due to slow disintegration and dissolution of tablets or capsules
Lag time
Series of structurally related chemical compounds that have shown interesting pharmacologically active and from which drug candidates may be selected
Leads
Dose size used in initiating therapy so as to yield therapeutic concentration which will result in clinical effectiveness
Loading dose, priming dose or initial dose
Obtained when drug is administered at the site where the pharmacological response is desired and when the drug released from the product acts by absorption to the skin or mucosa or penetrates into the skin or mucosa but does not enter the systemic blood circulation or lympathic system
Local effect
Dose size required to maintain the clinical effectiveness or therapeutic concentration according to the dosage regimen
Maintenance dose
Sum of all the chemical reactions for biotransformation of endogenous and exogenous substance which take place in the living cell
Metabolism
Includes buccal, sublingual, and perlingual administration routes where the drug is absorbed from the mouth cavity
Oral administration
There is no first pass effect
Oral administration
Sum of all body regions to which a drug eventually distributes, but is not in instantaneous equilibrium
Peripheral compartment
Indicates that dosage form is swallowed and the drug is absorbed from the GI tract
Peroral administration
Drug products that contain the identical therapeutic moiety or its precursor, but not necessarily in the same amount or dosage form or as the same salt or ester
Pharmaceutical alternatives
Drug products that contain identical amouts of the active pharmaceutical ingredient ( ex. Same salt or ester of the same therapeutic moiety), in identical dosage forms, but not necessarily containing the same inactive ingredients
Pharmaceutical equivalents
Changes of drug concentration in the drug product and changes of concentration of a drug and or/its metabolites in the human or animal body following administration
Pharmacokinetics
Occurs when the drug combines with plasma protein to form a reversible complex
Protein binding
Process with the slowest rate constant in a system of simultaneous kinetic process
Rate-limiting step
Site in the biophase to which drug molecules can be bound
Receptor
Usually a protein or proteinaceous material
Aka substrate
Receptor
Extent of drug absorbed upon extravascular administration in comparison to the dose size of a standard administration by same route
Relative bioavailability
Method of representing experimental data describing exponential processes that allow them to be presented in linear form
Semi logarithmic plot
Substances that have no pharmacological properties of their own in the amount used, but which can improve the penetration of drugs into the skin or their permeation through the skin or mucosa by reducing the barrier substances
Sorption promoters or permeation enhancers
Level of drug accumulation in blood and tissue upon multiple dosing when input and output are at equilibrium
Steady state
Those whose pharmacological action is not directly dependent on chemical structure,
They have no f. Group
Highly lipophilic
Do not react easily
They act by physicochemical process
Examples ether, nitrous oxide, halothane, phenol, ethyl alcohol, octyl alcohol and acetone
Structurally nonspecific drugs
Those whose pharmacological action results primarily from their chemical structure
They have f. Group
Combine to the three dimensional structure of receptors in the biophase
Ex. Antibiotics, sulfonamides, glycosides, alkaloids
Structurally specific drugs
Property of prolonged release dosage forms where the liberation (drug release) rate constant is smaller than the unrestricted absorption rate constant
Sustained release
Obtained when the drug release from the drug product enters the blood stream or lympathic stream and is distributed within the body - or at least in several organs - regardless of the site and route of administration
Systemic effect
Physical barrier to transport in the body.
Unit membrane
Lipoidal in nature and consists of a double row of phospholipids sandwiched between one layer each of protein
Unit membrane
Phenomenon that occurs when drugs filtered through the glomeruli are reabsorbed from the tubuli into systemic circulation
Urinary recycling
Additives which are necessary in formulating a dosage form from the drug
Vehicle substances
Should be chemically inert and should not have any pharmacological effect in the dose used
Vehicle substances
Are used to produce, from a relatively small amount of drug, a dosage form of the desired strength, volume and form or consistently suitable for administration
Vehicle substances
Hypothetical volume of body fluid that would be required to dissolve amount of drug at the same concentration as that found in the blood
Volume of distribution
