BioPharmaceutics Dr Farah Flashcards
Pharmacokinetics is _________________
the study of the kinetics of absorption, distribution, metabolism and excretion (ADME) of the drugs and their corresponding pharmacologic, therapeutic or toxic
response in animals and man.”
Absorption: is ____________________
Distribution: the __________________
The distribution of the drug between tissues is dependent on ____________________
the movement of the drug into the blood stream.
reversible transfer of a drug from one location to another within the body.
vascular permeability, regional blood flow, cardiac output and perfusion rate of the tissue and the ability of the drug to
bind tissue and plasma proteins and its lipid solubility.
pH partition plays a major role as well.
The drug is easily distributed in ________________
It is distributed in small quantities through_______________
Metabolism: is the metabolic _________________________
highly perfused organs such as the liver, heart and kidney.
less perfused tissues like muscle, fat and peripheral organs.
breakdown of drugs by living organisms, usually through specialized enzymatic systems.
pH partition plays a major role as well.
The rate of metabolism determines ________________
Excretion/ elimination: of a drug is one of ___________
The kidney is the main ________________. These organs or structures use specific routes to expel a drug from the body, these are termed elimination pathways.
the duration and intensity of a drug’s pharmacologic action.
a number of processes by which a drug is eliminated from an organism either in an unaltered form (unbound molecules) or modified as a metabolite.
excretory organ although others exist such as the liver, the skin, the lungs or glandular structures, such as
the salivary glands and the lacrimal glands.
the higher the surface area the higher the _____________
dissolution rate
describe slide 4
see slide 4
what makes up the Total body fluid(40L)
ECF (extracellular fluid) 15L
Interstitial fluid (12L)
Blood plasma
(3L)
ICF(intracellular fluid) 25L
Blood
plasma
(3L)
Transcellular
fluid(5L)
ECF (extracellular fluid) 15L
ICF(intracellular fluid) 25L
Blood plasma is __
3 litres
Transcellular fluid is ____________
5 litres
what is biopharmaceutics
It is the study of physiochemical properties of the drugs, their proper dosage form in which administered and the route of administration as related to the onset, duration and intensity of drug action.
Biopharmaceutics embraces the knowledge of factors that influence: list 4
- Protection of the pharmacological activity of the drug in the drug product
- The release of the drug from drug product
- The rate of dissolution of drug at the site of administration
- The system absorption of the drug (rate and extent).
Clinical pharmacokinetics
“Study of time course of _____________________”
This science may be applied to a wide range of clinical situations (renal, cardiac, hepatic, diabetes mellitus etc)
More correctly clinical pharmacokinetics is the ______________________________
absorption, distribution, metabolism and excretion of drugs and their corresponding pharmacological response.
application of pharmacokinetic principles in appropriate and rational drug therapy patient’s status (host factors)and disease state influence the PK of the drug.
which study deals with the Pk differences of drugs in various population groups.
Population pharmacokinetics
Toxicokinetic evaluation is both a ____and ________requirement in the drug development process.
regulatory
scientific
Toxicokinetic
It includes the generation of data to asses the systemic exposure. These data (ADME)help to understand _______ to and also play a role in clinical setting, assisting in the setting of plasma limits for ____________
observed toxicity
administered dose
early human exposure and in calculation of safety margins.
Drug substance is
It is the active pharmaceutical ingredient or component in the drug product that produces the pharmacodynamic activity
Drug product is
A drug product is the finished dosage form (tablets, syrups or injections) that contains the active ingredient
Bioequivalence requirement is?
The requirement imposed by FDA for in vitro and in vivo testing of particular drug products which must be satisfied as a condition of marketing.
Bioequivalent drug products
For systemically absorbed drugs the test drug (generic/non patent)and reference drug (branded)shall be considered bioequivalent
- If the rate and extent of absorption of test drug don’t differ significantly from the ~_____________when given administered at the same molar dose of therapeutic ingredient under ________________
rate and extent of absorption of reference drug
similar experimental conditions in either a single dose or multiple doses.
Bioequivalence
The extent of absorption of test drug does not show significant difference from _____________when at the same molar dose of therapeutic ingredient under ______________. As well, this difference in rate of absorption does not influence therapeutic objectives when test drug used chronically.
the extent of absorption of reference drug
similar experimental conditions in either a single dose or multiple doses and the difference from the reference drug in rate of absorption of test is intentional and mentioned on its proposed labelling
Drug concentration
Drug concentration is __________________
Drug levels are measured in ________________
an important element in determining individual or population pharmacokinetics
biological samples like plasma, saliva, milk and urine. Sometimes hair and nails are also sites where drugs can accumulate.
Two methods are used for sampling
- Non- invasive method:
Include sampling of urine, saliva, milk, faeces, expired air or any other biological material that can be obtained without parenteral or surgical intervention.
Invasive method
Non- invasive method
Invasive method includes?
Include sampling of blood, spinal fluid, synovial fluid, tissue biopsy or any biological material that requires parenteral or surgical intervention in the patient.
Non- invasive method includes
Include sampling of urine, saliva, milk, faeces, expired air or any other biological material that can be obtained without parenteral or surgical intervention.
______________ is the most convenient and direct method to assess the PK of the drug in the body.
Whole blood contains_______________.
_______________ is most commonly used for measuring drug concentration.
Plasma perfuses _______________
For practical purpose, it is assumed that t____________is in dynamic equilibrium with the tissues, the changes in plasma drug concentration will reflect corresponding changes in tissue drug concentration.
Plasma: __________coloured clear liquid, _________% water,____________% of solid Serum= plasma -fibrinogen
Measurement of drug concentration in the blood, plasma or serum is the most convenient and direct method to assess the PK of the drug in the body.
Whole blood contains formed elements (WBCs, RBCs and platelets) and protein like albumin and globulins.
Generally serum or plasma is most commonly used for measuring drug concentration.
Plasma perfuses all tissues of the body and cellular elements in the blood.
For practical purpose, it is assumed that the drug in plasma is in dynamic equilibrium with the tissues, the changes in plasma drug concentration will reflect corresponding changes in tissue drug concentration.
Plasma: straw coloured clear liquid 91 to 92% water, 8 to 9% of solid Serum= plasma -fibrinogen
Plasma Level time curve
The plasma level time curve is _______________
Samples are taken at _______________
The concentration in each plasma sample is plotted on ___________________.
The plasma level time curve is constructed by measuring drug concentrations in plasma
Samples are taken at various time intervals after the administration of a drug product.
The concentration in each plasma sample is plotted on rectilinear graph paper against corresponding time at which the sample was withdrawn.
Minimum effective concentration (MEC) represents ______________(for therapeutic purpose this the minimum concentration needed to be present at the receptor to produce desired effect)
MEC represents the minimum concentration of the drug needed to produce the pharmacological effect (for therapeutic purpose this the minimum concentration needed to be present at the receptor to produce desired effect)
Minimum toxic concentration(MTC) reflects _________________
Minimum toxic concentration(MTC) reflects the minimum concentration of drug needed to need just barely produce a toxic effect
Intensity of pharmacological response is proportional ___________, which is reflected in the observation that higher plasma drug concentrations produce___________
Intensity of pharmacological response is proportional to the number of drug receptors occupied, which is reflected in the observation that higher plasma drug concentrations produce a greater response, up to a maximum.
___________corresponds to the time required for the drug concentration to reach the MEC.
Onset time.
The time between the administration of the drug and the start of the absorption is _________
Lag time
Time required to reach Cmax is
Tmax.
what represents the maximum plasma drug concentration obtained after administration of drug. (usually by oral route)
Peak plasma level (Cmax).
Drug concentration in urine and faeces
The measurement of drug concentration in urine is ___________________
The rate and extent of drug excretion reflects ________________
Urinary blood excretion data can also be used to calculate _______________
_____________ reflects the amount of unabsorbed drug following oral administration of a dose or may reflect the amount of drug that is secreted in bile ( and not reabsorbed) after systemic absorption.
The measurement of drug concentration in urine is indirect method of measuring the bioavailability.
The rate and extent of drug excretion reflects the rate and extent of systemic drug absorption.
Urinary blood excretion data can also be used to calculate PK parameters.
Measurements of drug in faeces reflects the amount of unabsorbed drug following oral administration of a dose or may reflect the amount of drug that is secreted in bile ( and not reabsorbed) after systemic absorption.
Drug concentration in saliva
__________diffuses in saliva
Saliva drug levels nearly parallel the free drug rather than ________________
The saliva drug concentrations, taken after equilibrium with plasma drug concentration, generally provides____________________
Free drug (unbound) diffuses in saliva
Saliva drug levels nearly parallel the free drug rather than total plasma drug concentration.
The saliva drug concentrations, taken after equilibrium with plasma drug concentration, generally provides more stable indication of drug levels in the body.
_______________is the measure of rate and extent of active ingredients or active moiety of a drug product that reaches the systemic circulation and becomes available at the site of action.
______________is the availability of the drug from a drug product (test) compared to a recognized standard (reference).
R.A= [AUC]test/[AUC]reference
Bioavailability is the measure of rate and extent of active ingredients or active moiety of a drug product that reaches the systemic circulation and becomes available at the site of action.
Relative availability:
is the availability of the drug from a drug product (test) compared to a recognized standard (reference).
R.A= [AUC]test/[AUC]reference
stop
stopped at slide 24
