This document provides an overview of pharmacokinetics, biopharmaceutics, pharmacodynamics, and related topics. It defines key terms and concepts in 3 sentences:
Pharmacokinetics describes the absorption, distribution, and elimination of drugs in the body. Biopharmaceutics examines how a drug's properties interact with the dosage form and administration route to influence absorption. Pharmacodynamics is the study of how drugs act on the body including their mechanisms of action and relationships between concentrations and effects.
The document then discusses pharmacokinetic and physiologically-based models that use mathematical functions to predict drug concentrations over time based on dosing. It also introduces compartmental models which conceptually group tissues based on drug distribution and
Michaelis-Menten kinetics is commonly used to describe non-linear pharmacokinetics when drug metabolism or elimination involves saturable enzyme systems. Non-linearity occurs when the capacity of the enzyme is exceeded, leading to saturation. This document discusses various causes and examples of non-linear pharmacokinetics, including saturation of absorption, distribution, metabolism and excretion processes. It also describes the two-compartment open model and how drug concentrations change in each compartment over time following intravenous bolus dosing.
This document provides an introduction to pharmacology concepts. It discusses what drugs are and how they work in the body. It covers absorption, distribution, metabolism, and excretion of drugs. Absorption involves passive diffusion, carrier-mediated transport, and endocytosis. Distribution depends on blood flow, protein binding, and accumulation in tissues. Metabolism occurs mainly in the liver through phase I and phase II reactions. Excretion involves renal and hepatic systems with water-soluble drugs or metabolites excreted in urine or bile.
Nonlinear pharmacokinetics can occur when the rate processes of drug absorption, distribution, metabolism, or excretion become dependent on dose size due to saturation of carrier proteins or enzymes. Some specific causes of nonlinearity include saturation of transporters during drug absorption, saturation of plasma protein binding sites or tissue binding sites during distribution, capacity-limited drug metabolism by enzyme saturation, and saturation of active tubular secretion or reabsorption processes during excretion. The Michaelis-Menten equation can describe the kinetics of these saturable, capacity-limited processes.
The document discusses the application of pharmacokinetics in new drug development and designing dosage forms. Pharmacokinetics helps understand how the body affects a drug after administration through absorption, distribution, metabolism and excretion. It is used in drug design, developing dosage regimens, and improving drug therapy. Pharmacokinetics principles can be applied to developing controlled release drugs and increasing bioavailability. Factors like lipophilicity and solubility affect drug absorption, and properties like volume of distribution and clearance impact half-life. Pharmacokinetics also aids in identifying metabolic pathways and drug-metabolizing enzymes. Protein binding influences pharmacokinetic properties and drug effects.
Pharmacokinetics / Biopharmaceutics - IntroductionAreej Abu Hanieh
This document provides an introduction to pharmacokinetics, biopharmaceutics, pharmacodynamics, clinical pharmacokinetics, and toxicokinetics. It discusses how pharmacokinetics describes the absorption, distribution, metabolism and excretion of drugs in the body. Biopharmaceutics examines how the physical properties of drugs and dosage forms influence drug absorption. Pharmacodynamics studies the biochemical and physiological effects of drugs. Clinical pharmacokinetics applies these principles to optimize drug therapy for patients. Toxicokinetics and clinical toxicology evaluate adverse drug effects.
The presentation concisely describes the different pharmacokinetic parameters and basics of compartment modelling. It will help undergraduate students to understand the basic concepts of Biopharmaceutics.
This document discusses clinical pharmacokinetics and pharmacodynamics. It defines pharmacokinetics as how the body affects a drug through absorption, distribution, metabolism and elimination. Factors like age can impact these processes in pediatric patients. It also discusses pharmacodynamics, how drugs act on the body, and how pharmacokinetics and pharmacodynamics together can help individualize drug therapy and decrease adverse effects.
This document provides an overview of key pharmacokinetic concepts including bioavailability, Cmax, distribution, half-life, Tmax, and area under the curve (AUC). Bioavailability describes the amount of drug that reaches systemic circulation. Cmax is the maximum drug concentration in blood plasma. Distribution describes drugs binding to plasma proteins. Half-life is the time for drug concentration to reduce by half. Tmax is the time to reach Cmax. AUC represents total drug absorption over time.
Michaelis-Menten kinetics is commonly used to describe non-linear pharmacokinetics when drug metabolism or elimination involves saturable enzyme systems. Non-linearity occurs when the capacity of the enzyme is exceeded, leading to saturation. This document discusses various causes and examples of non-linear pharmacokinetics, including saturation of absorption, distribution, metabolism and excretion processes. It also describes the two-compartment open model and how drug concentrations change in each compartment over time following intravenous bolus dosing.
This document provides an introduction to pharmacology concepts. It discusses what drugs are and how they work in the body. It covers absorption, distribution, metabolism, and excretion of drugs. Absorption involves passive diffusion, carrier-mediated transport, and endocytosis. Distribution depends on blood flow, protein binding, and accumulation in tissues. Metabolism occurs mainly in the liver through phase I and phase II reactions. Excretion involves renal and hepatic systems with water-soluble drugs or metabolites excreted in urine or bile.
Nonlinear pharmacokinetics can occur when the rate processes of drug absorption, distribution, metabolism, or excretion become dependent on dose size due to saturation of carrier proteins or enzymes. Some specific causes of nonlinearity include saturation of transporters during drug absorption, saturation of plasma protein binding sites or tissue binding sites during distribution, capacity-limited drug metabolism by enzyme saturation, and saturation of active tubular secretion or reabsorption processes during excretion. The Michaelis-Menten equation can describe the kinetics of these saturable, capacity-limited processes.
The document discusses the application of pharmacokinetics in new drug development and designing dosage forms. Pharmacokinetics helps understand how the body affects a drug after administration through absorption, distribution, metabolism and excretion. It is used in drug design, developing dosage regimens, and improving drug therapy. Pharmacokinetics principles can be applied to developing controlled release drugs and increasing bioavailability. Factors like lipophilicity and solubility affect drug absorption, and properties like volume of distribution and clearance impact half-life. Pharmacokinetics also aids in identifying metabolic pathways and drug-metabolizing enzymes. Protein binding influences pharmacokinetic properties and drug effects.
Pharmacokinetics / Biopharmaceutics - IntroductionAreej Abu Hanieh
This document provides an introduction to pharmacokinetics, biopharmaceutics, pharmacodynamics, clinical pharmacokinetics, and toxicokinetics. It discusses how pharmacokinetics describes the absorption, distribution, metabolism and excretion of drugs in the body. Biopharmaceutics examines how the physical properties of drugs and dosage forms influence drug absorption. Pharmacodynamics studies the biochemical and physiological effects of drugs. Clinical pharmacokinetics applies these principles to optimize drug therapy for patients. Toxicokinetics and clinical toxicology evaluate adverse drug effects.
The presentation concisely describes the different pharmacokinetic parameters and basics of compartment modelling. It will help undergraduate students to understand the basic concepts of Biopharmaceutics.
This document discusses clinical pharmacokinetics and pharmacodynamics. It defines pharmacokinetics as how the body affects a drug through absorption, distribution, metabolism and elimination. Factors like age can impact these processes in pediatric patients. It also discusses pharmacodynamics, how drugs act on the body, and how pharmacokinetics and pharmacodynamics together can help individualize drug therapy and decrease adverse effects.
This document provides an overview of key pharmacokinetic concepts including bioavailability, Cmax, distribution, half-life, Tmax, and area under the curve (AUC). Bioavailability describes the amount of drug that reaches systemic circulation. Cmax is the maximum drug concentration in blood plasma. Distribution describes drugs binding to plasma proteins. Half-life is the time for drug concentration to reduce by half. Tmax is the time to reach Cmax. AUC represents total drug absorption over time.
Estimation of pharmacokinetic parametersKarun Kumar
This document discusses key pharmacokinetic parameters that can be estimated including those related to absorption, distribution, and elimination of drugs in the body. It provides definitions and formulas for parameters such as bioavailability, absorption rate constant, volume of distribution, clearance, and half-life. Methods for measuring the area under the plasma concentration-time curve are also outlined. Factors that can influence bioavailability like pharmaceutical properties and physiological factors are briefly explained.
Drugs work by being absorbed from the stomach and small intestine and traveling through the bloodstream to their site of action, usually interacting with receptors on cells. It can take 10-15 years and over 5000 compounds to develop a new drug that is approved for human use. Generic drugs are approved after the patent expires on the original drug. Drugs can act in various ways including chemically or physically reacting, modifying metabolism, interfering with cell function, or modifying neurotransmitters. Their concentration in the blood over time and therapeutic window are important, as is their absorption, distribution, metabolism and excretion in the body. Many factors can influence individual drug responses.
This document discusses bioavailability of drugs that follow nonlinear pharmacokinetics and chronopharmacokinetics. It defines nonlinear pharmacokinetics as drug absorption, distribution, and elimination processes that are dependent on carrier enzymes and can become saturated at high drug concentrations. It also defines chronopharmacokinetics as changes in drug absorption, distribution, metabolism and elimination due to circadian rhythms. Key aspects that can vary in a circadian manner include gastric emptying, gastrointestinal blood flow, liver enzyme activity, renal blood flow, and urinary pH. Understanding these nonlinear and circadian factors is important for accurate therapeutic drug monitoring and reducing side effects.
This document discusses pharmacokinetic models used to mathematically represent how drugs move through the body over time. It covers one compartment models, which assume rapid equilibrium between blood and tissues. For intravenous bolus administration, drug concentration decreases exponentially according to first-order kinetics. Key parameters include elimination rate constant, half-life, volume of distribution, and clearance. Compartmental modelling is useful for predicting drug concentrations, determining dosing schedules, and understanding drug interactions.
The document discusses biopharmaceutics and factors influencing drug absorption. Biopharmaceutics studies how the chemical and physical properties of drugs and dosage forms affect drug absorption rates and levels based on the route of administration. Drug absorption is influenced by physiological factors like membrane transport mechanisms, gastrointestinal physiology, gastric emptying time, and the effect of food. Absorption also depends on chemical-physical properties of the drug and formulation factors. The goal of biopharmaceutics is to understand how these factors impact drug bioavailability, protection/stability, release rates, and pharmacologic effects.
This document provides an overview of pharmacokinetics, including definitions, compartment models, non-compartment models, physiological models, and a one-compartment open model. Pharmacokinetics describes the absorption, distribution, metabolism, and excretion of drugs in the body. Compartmental models represent the body as a series of compartments and use rate constants to describe drug movement between compartments. A one-compartment open model can be used to model intravenous bolus administration, where drug is eliminated from the body via first-order kinetics.
[1] The document discusses basic pharmacokinetic concepts including bioavailability, volume of distribution, and elimination kinetics.
[2] Bioavailability refers to the extent of absorption of an administered dose and is expressed as a percentage or fraction relative to intravenous administration. It depends on factors like absorption, first-pass metabolism, and solubility.
[3] Volume of distribution is a theoretical volume in which an administered dose would be distributed if concentrations were uniform throughout body water compartments. It is calculated based on plasma concentration and the administered dose.
[4] Drugs can follow first-order or zero-order elimination kinetics. First-order kinetics involve a fixed fraction eliminated per unit time while zero-order
Pharmacokinetics is the study of drug absorption, distribution, metabolism, and excretion in the body. The key pharmacokinetic parameters include volume of distribution (Vd), clearance (CL), and elimination half-life (t1/2). Vd represents the apparent volume needed to contain the total amount of drug at the observed plasma concentration. CL is the volume of plasma cleared of drug per unit time, determined by metabolism and excretion. t1/2 is the time for drug concentration to reduce by half, dependent on Vd and CL. These parameters allow quantification of drug behavior in the body over time.
Excretion of drugs and kinetics of eliminationmohamed sanooz
1) There are various routes of drug excretion including urine, feces, exhaled air, saliva, sweat and milk.
2) Renal excretion is the major route and involves glomerular filtration, tubular reabsorption and tubular secretion. Drug clearance and kinetics of elimination such as first and zero order can be used to design dosage regimens.
3) Repeated drug administration may use loading and maintenance doses to rapidly reach and maintain therapeutic drug levels under the plateau and target level principles.
Clinical pharmacokinetics is the quantitative study of drug movement in, through, and out of the body. It involves the processes of absorption, distribution, metabolism, and excretion (ADME). Pharmacokinetics helps understand how the body affects a drug over time. Drugs are transported across biological membranes via passive diffusion, filtration, or specialized carrier transport systems. Once in circulation, drugs are distributed to tissues depending on factors like lipid solubility and plasma protein binding. The liver is the primary site of drug metabolism, which alters drugs through oxidation, reduction, hydrolysis, and conjugation to make them more polar and excretable. Understanding a drug's pharmacokinetics allows for individualization of drug therapy and
This document discusses chronopharmacokinetics and circadian rhythms. It begins by explaining that drug absorption, distribution, metabolism and elimination can vary based on the time of day due to physiological rhythms. It then defines chronopharmacokinetics as studying how drug plasma levels vary based on the time of administration. Key factors that can cause time-dependent variations, like changes in GI function, enzyme activity and organ blood flow, are summarized. Examples are given of disease symptoms and drug effects that vary over 24-hour periods. Finally, applications of chronotherapeutic drug delivery systems are briefly mentioned to maximize drug effects at specific times.
This document discusses various approaches used to model pharmacokinetics. It describes compartment models, physiological models, and distributed parameter models that can be used to mathematically describe drug absorption, distribution, metabolism and excretion over time. It also discusses model-independent or non-compartmental analysis, which does not require assumptions about specific compartment models. Compartment models include mammillary and catenary models. Physiological models group tissues into compartments based on similar perfusion properties. Distributed parameter models account for variations in organ blood flow and drug diffusion.
1. Absorption is the movement of a drug into the blood circulation. Drugs can cross cell membranes through passive transport like diffusion or facilitated diffusion, or through active transport using carrier proteins and ATP.
2. Passive transport includes diffusion down a concentration gradient, facilitated diffusion using carrier proteins, filtration through membrane pores, and osmosis. Active transport moves drugs against a concentration gradient using ATP, including primary transport directly using ATP or secondary co-transport coupling to another gradient.
3. Many factors influence drug absorption, including lipid solubility, molecular size, particle size, degree of ionization, physical and chemical form, dosage form, concentration, area of absorptive surface, vascularity, pH,
Pharma co kinetics compartmental modeling Manjit Kaur
This document discusses pharmacokinetic models. It begins by covering basic considerations like compartment models, one compartment models for intravenous bolus administration and infusion, and extravascular administration. It also discusses multi-compartment models, non-linear pharmacokinetics including Michaelis-Menten kinetics, and drug interactions. Specific models and concepts covered in more depth include one compartment models, two compartment models, mixed order kinetics, Michaelis-Menten equation, plasma drug concentration profiles, and pharmacodynamic parameters.
This document provides an overview of basic concepts in biopharmaceutics including pharmacokinetic models and parameters. It discusses pharmacokinetic concepts like dosage regimen, pharmacokinetics, plasma drug concentration profiles, and pharmacokinetic parameters including Cmax, tmax, AUC, etc. It also covers pharmacokinetic models including compartment models, physiological models, and non-compartmental analysis. Specific compartment models like one-compartment open model for IV bolus and IV infusion are explained. Rate constants, orders of reactions, and processes like zero-order, first-order, and mixed-order kinetics are defined. Methods for estimating pharmacokinetic parameters from plasma concentration-time data are also summarized.
This document discusses pharmacokinetics and provides details about various pharmacokinetic parameters and models. It begins by defining pharmacokinetics as the study of the kinetics of drug absorption, distribution, metabolism and excretion. It then describes parameters that can be evaluated from plasma drug concentration-time profiles, including Cmax, Tmax, and AUC. Next, it discusses compartment models and physiological models that are used to analyze pharmacokinetic data and predict drug disposition. It concludes by covering the model-independent approach of noncompartmental analysis.
INTRODUCTION TO PHARMACOKINETIC MODELS, ONE COMPARTMENT OPEN MODEL IV BOLUS, IV INFUSION, EXTRAVASCULAR ADMINISTRATION, WAGNER NELSON METHOD, METHOD OF RESIDUALS
Nonlinear pharmacokinetics occurs when the body's processing of a drug is saturated at higher doses, causing kinetics parameters like clearance and half-life to change with dose. Michaelis-Menten kinetics are commonly used to model nonlinear metabolism, where the metabolic rate approaches a maximum (Vmax) at high concentrations. Parameters like Vmax and KM can be estimated from steady-state dosing and concentration data by linearizing the Michaelis-Menten equation. Drugs like phenytoin exhibit nonlinear kinetics due to capacity-limited hepatic metabolism.
INTRODUCTION TO BIOPHARMACEUTICS , pharmacokinetics, pharmacodynamics and the...krishna keerthi
Biopharmaceutics is a field within the pharmaceutical science that explores the relationship between the formulation of a drug and its pharmacological effects. it delves into how a drug is absorbed, distributed, metabolized, and excreted in the body, aiming to optimize drug delivery for enhanced therapeutic outcomes. this discipline integrates principles of pharmacokinetics , pharmacodynamics and pharmaceutical technology to understand the factors influencing drug bioavailability and efficacy.
This document provides information about the pharmacokinetics course taught by Dr. Mariam Abdel Jalil. It lists textbooks and references used in the course. It outlines classroom standards and student responsibilities. It defines pharmacokinetics as the movement of drugs in the body, including absorption, distribution, metabolism and excretion. It discusses why pharmacokinetics is studied, such as determining dosing regimens. It reviews the basic ADME processes and distinguishes pharmacokinetics from pharmacodynamics. It discusses experimental and theoretical approaches to studying pharmacokinetics, including measuring drug concentrations in samples and developing models.
Estimation of pharmacokinetic parametersKarun Kumar
This document discusses key pharmacokinetic parameters that can be estimated including those related to absorption, distribution, and elimination of drugs in the body. It provides definitions and formulas for parameters such as bioavailability, absorption rate constant, volume of distribution, clearance, and half-life. Methods for measuring the area under the plasma concentration-time curve are also outlined. Factors that can influence bioavailability like pharmaceutical properties and physiological factors are briefly explained.
Drugs work by being absorbed from the stomach and small intestine and traveling through the bloodstream to their site of action, usually interacting with receptors on cells. It can take 10-15 years and over 5000 compounds to develop a new drug that is approved for human use. Generic drugs are approved after the patent expires on the original drug. Drugs can act in various ways including chemically or physically reacting, modifying metabolism, interfering with cell function, or modifying neurotransmitters. Their concentration in the blood over time and therapeutic window are important, as is their absorption, distribution, metabolism and excretion in the body. Many factors can influence individual drug responses.
This document discusses bioavailability of drugs that follow nonlinear pharmacokinetics and chronopharmacokinetics. It defines nonlinear pharmacokinetics as drug absorption, distribution, and elimination processes that are dependent on carrier enzymes and can become saturated at high drug concentrations. It also defines chronopharmacokinetics as changes in drug absorption, distribution, metabolism and elimination due to circadian rhythms. Key aspects that can vary in a circadian manner include gastric emptying, gastrointestinal blood flow, liver enzyme activity, renal blood flow, and urinary pH. Understanding these nonlinear and circadian factors is important for accurate therapeutic drug monitoring and reducing side effects.
This document discusses pharmacokinetic models used to mathematically represent how drugs move through the body over time. It covers one compartment models, which assume rapid equilibrium between blood and tissues. For intravenous bolus administration, drug concentration decreases exponentially according to first-order kinetics. Key parameters include elimination rate constant, half-life, volume of distribution, and clearance. Compartmental modelling is useful for predicting drug concentrations, determining dosing schedules, and understanding drug interactions.
The document discusses biopharmaceutics and factors influencing drug absorption. Biopharmaceutics studies how the chemical and physical properties of drugs and dosage forms affect drug absorption rates and levels based on the route of administration. Drug absorption is influenced by physiological factors like membrane transport mechanisms, gastrointestinal physiology, gastric emptying time, and the effect of food. Absorption also depends on chemical-physical properties of the drug and formulation factors. The goal of biopharmaceutics is to understand how these factors impact drug bioavailability, protection/stability, release rates, and pharmacologic effects.
This document provides an overview of pharmacokinetics, including definitions, compartment models, non-compartment models, physiological models, and a one-compartment open model. Pharmacokinetics describes the absorption, distribution, metabolism, and excretion of drugs in the body. Compartmental models represent the body as a series of compartments and use rate constants to describe drug movement between compartments. A one-compartment open model can be used to model intravenous bolus administration, where drug is eliminated from the body via first-order kinetics.
[1] The document discusses basic pharmacokinetic concepts including bioavailability, volume of distribution, and elimination kinetics.
[2] Bioavailability refers to the extent of absorption of an administered dose and is expressed as a percentage or fraction relative to intravenous administration. It depends on factors like absorption, first-pass metabolism, and solubility.
[3] Volume of distribution is a theoretical volume in which an administered dose would be distributed if concentrations were uniform throughout body water compartments. It is calculated based on plasma concentration and the administered dose.
[4] Drugs can follow first-order or zero-order elimination kinetics. First-order kinetics involve a fixed fraction eliminated per unit time while zero-order
Pharmacokinetics is the study of drug absorption, distribution, metabolism, and excretion in the body. The key pharmacokinetic parameters include volume of distribution (Vd), clearance (CL), and elimination half-life (t1/2). Vd represents the apparent volume needed to contain the total amount of drug at the observed plasma concentration. CL is the volume of plasma cleared of drug per unit time, determined by metabolism and excretion. t1/2 is the time for drug concentration to reduce by half, dependent on Vd and CL. These parameters allow quantification of drug behavior in the body over time.
Excretion of drugs and kinetics of eliminationmohamed sanooz
1) There are various routes of drug excretion including urine, feces, exhaled air, saliva, sweat and milk.
2) Renal excretion is the major route and involves glomerular filtration, tubular reabsorption and tubular secretion. Drug clearance and kinetics of elimination such as first and zero order can be used to design dosage regimens.
3) Repeated drug administration may use loading and maintenance doses to rapidly reach and maintain therapeutic drug levels under the plateau and target level principles.
Clinical pharmacokinetics is the quantitative study of drug movement in, through, and out of the body. It involves the processes of absorption, distribution, metabolism, and excretion (ADME). Pharmacokinetics helps understand how the body affects a drug over time. Drugs are transported across biological membranes via passive diffusion, filtration, or specialized carrier transport systems. Once in circulation, drugs are distributed to tissues depending on factors like lipid solubility and plasma protein binding. The liver is the primary site of drug metabolism, which alters drugs through oxidation, reduction, hydrolysis, and conjugation to make them more polar and excretable. Understanding a drug's pharmacokinetics allows for individualization of drug therapy and
This document discusses chronopharmacokinetics and circadian rhythms. It begins by explaining that drug absorption, distribution, metabolism and elimination can vary based on the time of day due to physiological rhythms. It then defines chronopharmacokinetics as studying how drug plasma levels vary based on the time of administration. Key factors that can cause time-dependent variations, like changes in GI function, enzyme activity and organ blood flow, are summarized. Examples are given of disease symptoms and drug effects that vary over 24-hour periods. Finally, applications of chronotherapeutic drug delivery systems are briefly mentioned to maximize drug effects at specific times.
This document discusses various approaches used to model pharmacokinetics. It describes compartment models, physiological models, and distributed parameter models that can be used to mathematically describe drug absorption, distribution, metabolism and excretion over time. It also discusses model-independent or non-compartmental analysis, which does not require assumptions about specific compartment models. Compartment models include mammillary and catenary models. Physiological models group tissues into compartments based on similar perfusion properties. Distributed parameter models account for variations in organ blood flow and drug diffusion.
1. Absorption is the movement of a drug into the blood circulation. Drugs can cross cell membranes through passive transport like diffusion or facilitated diffusion, or through active transport using carrier proteins and ATP.
2. Passive transport includes diffusion down a concentration gradient, facilitated diffusion using carrier proteins, filtration through membrane pores, and osmosis. Active transport moves drugs against a concentration gradient using ATP, including primary transport directly using ATP or secondary co-transport coupling to another gradient.
3. Many factors influence drug absorption, including lipid solubility, molecular size, particle size, degree of ionization, physical and chemical form, dosage form, concentration, area of absorptive surface, vascularity, pH,
Pharma co kinetics compartmental modeling Manjit Kaur
This document discusses pharmacokinetic models. It begins by covering basic considerations like compartment models, one compartment models for intravenous bolus administration and infusion, and extravascular administration. It also discusses multi-compartment models, non-linear pharmacokinetics including Michaelis-Menten kinetics, and drug interactions. Specific models and concepts covered in more depth include one compartment models, two compartment models, mixed order kinetics, Michaelis-Menten equation, plasma drug concentration profiles, and pharmacodynamic parameters.
This document provides an overview of basic concepts in biopharmaceutics including pharmacokinetic models and parameters. It discusses pharmacokinetic concepts like dosage regimen, pharmacokinetics, plasma drug concentration profiles, and pharmacokinetic parameters including Cmax, tmax, AUC, etc. It also covers pharmacokinetic models including compartment models, physiological models, and non-compartmental analysis. Specific compartment models like one-compartment open model for IV bolus and IV infusion are explained. Rate constants, orders of reactions, and processes like zero-order, first-order, and mixed-order kinetics are defined. Methods for estimating pharmacokinetic parameters from plasma concentration-time data are also summarized.
This document discusses pharmacokinetics and provides details about various pharmacokinetic parameters and models. It begins by defining pharmacokinetics as the study of the kinetics of drug absorption, distribution, metabolism and excretion. It then describes parameters that can be evaluated from plasma drug concentration-time profiles, including Cmax, Tmax, and AUC. Next, it discusses compartment models and physiological models that are used to analyze pharmacokinetic data and predict drug disposition. It concludes by covering the model-independent approach of noncompartmental analysis.
INTRODUCTION TO PHARMACOKINETIC MODELS, ONE COMPARTMENT OPEN MODEL IV BOLUS, IV INFUSION, EXTRAVASCULAR ADMINISTRATION, WAGNER NELSON METHOD, METHOD OF RESIDUALS
Nonlinear pharmacokinetics occurs when the body's processing of a drug is saturated at higher doses, causing kinetics parameters like clearance and half-life to change with dose. Michaelis-Menten kinetics are commonly used to model nonlinear metabolism, where the metabolic rate approaches a maximum (Vmax) at high concentrations. Parameters like Vmax and KM can be estimated from steady-state dosing and concentration data by linearizing the Michaelis-Menten equation. Drugs like phenytoin exhibit nonlinear kinetics due to capacity-limited hepatic metabolism.
INTRODUCTION TO BIOPHARMACEUTICS , pharmacokinetics, pharmacodynamics and the...krishna keerthi
Biopharmaceutics is a field within the pharmaceutical science that explores the relationship between the formulation of a drug and its pharmacological effects. it delves into how a drug is absorbed, distributed, metabolized, and excreted in the body, aiming to optimize drug delivery for enhanced therapeutic outcomes. this discipline integrates principles of pharmacokinetics , pharmacodynamics and pharmaceutical technology to understand the factors influencing drug bioavailability and efficacy.
This document provides information about the pharmacokinetics course taught by Dr. Mariam Abdel Jalil. It lists textbooks and references used in the course. It outlines classroom standards and student responsibilities. It defines pharmacokinetics as the movement of drugs in the body, including absorption, distribution, metabolism and excretion. It discusses why pharmacokinetics is studied, such as determining dosing regimens. It reviews the basic ADME processes and distinguishes pharmacokinetics from pharmacodynamics. It discusses experimental and theoretical approaches to studying pharmacokinetics, including measuring drug concentrations in samples and developing models.
Clinical pharmacokinetic studies examine how the body absorbs, distributes, metabolizes, and excretes an investigational drug. Data from these studies help design subsequent clinical trials by determining appropriate dosages for different patient characteristics and predicting drug interactions. Analytical methods must be validated to accurately measure drug and metabolite concentrations in tissues. Pharmacokinetic studies using the final drug formulation are required before submitting a new drug application to regulators.
This document discusses therapeutic drug monitoring (TDM), including its definition, introduction, criteria for when it is useful/unnecessary, and process. TDM involves measuring drug concentrations in blood/plasma to help adjust dosages to a desired therapeutic range. It is especially useful for drugs with a narrow therapeutic index or large interindividual variability. The TDM process involves collecting a biological sample at steady state, requesting a lab analysis, the lab measuring the drug level using an appropriate analytical technique, communicating the results along with the therapeutic range, and the clinician interpreting the level based on dosage and patient factors. Commonly monitored drugs and some problems with TDM services are also mentioned.
Therapeutic drug monitoring involves measuring drug levels in patients' blood to ensure drug dosages produce therapeutic effects without toxicity. Several health professionals coordinate timing of blood collection, measuring drug levels, and reporting results to physicians for adjusting dosages. Therapeutic drug monitoring is especially important for drugs with a narrow range between therapeutic and toxic levels due to variability in absorption, distribution, metabolism and excretion between individuals. Proper collection and handling of blood samples is critical for obtaining accurate drug level measurements.
This document discusses measurements of bioavailability. It defines bioavailability and bioequivalence. There are two main methods to measure bioavailability - pharmacokinetic and pharmacodynamic. Pharmacokinetic methods include plasma level time studies and urinary excretion studies which measure parameters like Cmax, Tmax, and AUC from plasma data or urinary excretion rate and amount excreted from urine data. Pharmacodynamic methods include measuring acute pharmacological responses or therapeutic responses but have disadvantages like variable individual responses.
This document discusses factors that affect drug absorption and methods for conducting absorption studies. It defines absorption as a drug crossing a biological membrane from its site of administration into systemic circulation. Factors affecting absorption include drug properties like solubility and molecular size, as well as bodily factors like pH and disease state. Standard absorption studies involve giving subjects single or multiple doses of a drug and collecting blood, urine and other samples to determine pharmacokinetic parameters and evaluate absorption. Key aspects of study design addressed are subject selection, sample collection schedule, and parameters measured like bioavailability and absorption rate.
Definition of Biopharmaceutics, Application of Biopharmaceutics, Definition of Absorption, Distribution, Metabolism, Excretion, Pharmacokinetics, pharmacodynamics, Bioavailability, Bio-equivalence, Plasma Concentration Vs Time Profile, Pharmacokinetics & pharmacodynamics parameters
Methods For Assesment Of Bioavailability Anindya Jana
This document summarizes a seminar presentation on methods for determining bioavailability. It defines bioavailability as the rate and extent to which the active substance of a drug is absorbed and available at the site of action. It then describes the main objectives of bioavailability studies which include aiding new drug and formulation development. The key methods discussed for assessing bioavailability include measuring plasma drug concentration, urinary drug excretion, acute pharmacodynamic effects, clinical observations, and in vitro drug dissolution studies. Specific parameters are defined for each method such as Cmax, AUC, tmax, Du, and Emax. Finally, the document summarizes two literature articles that developed formulations to enhance the oral bioavailability of curcumin and edarav
The document discusses bioavailability and bioequivalence. It defines bioavailability as the rate and extent to which the active ingredient is absorbed from a drug product and becomes available at the site of action. Bioequivalence is achieved when two drug products containing the same active ingredient have the same rate and extent of absorption. The document outlines factors that affect bioavailability such as pharmaceutical, patient, and route of administration factors. It also describes various methods to measure bioavailability including pharmacokinetic and pharmacodynamic approaches.
Toxicokinetics is the study of how the body affects a toxic substance over time through absorption, distribution, metabolism, and excretion. Toxicokinetic studies help explain toxicity results by quantifying exposure levels in animals and relating them to dose levels and time. Such studies are important for interpreting toxicity findings, designing further studies, and assessing the relevance of results to human safety. Key objectives include describing systemic exposure levels in toxicity studies and relating them to toxic effects.
This document provides an introduction to biopharmaceutics. It defines key terms like biopharmaceutics, pharmacokinetics, pharmacodynamics, absorption, distribution, metabolism, excretion, bioavailability, and bioavailable dose. It also outlines the four main processes involved in drug administration and therapy: the pharmaceutical processes of drug formulation, the pharmacokinetic processes of absorption, distribution, metabolism and excretion, the pharmacodynamic processes of a drug's mechanism of action, and the therapeutic processes of translating pharmacological effects to clinical effects. Finally, it notes that a dosage regimen specifies the time interval and dose size for taking a drug.
Biopharmaceutics Part I
Arba minch unverisity college of health science
department of pharmacy
pharmaceutics and social pharmacy course team for 3rd year pharmacy student
Biopharmaceutics is important for pharmaceutical science:
1. Drug Formulation: Biopharmaceutics provides insights into the development and optimization of drug formulations. It considers factors such as drug solubility, stability, and bioavailability, which are critical for ensuring that a drug can be effectively administered to patients. By understanding the physicochemical properties of drugs, scientists can design appropriate dosage forms such as tablets, capsules, or injectables that deliver the drug in a controlled and efficient manner.
2. Drug Absorption and Bioavailability: Biopharmaceutics investigates how drugs are absorbed into the systemic circulation after administration. It examines processes such as dissolution, permeation, and transport across biological barriers, including the gastrointestinal tract. Understanding drug absorption is essential for predicting drug concentrations at the site of action and determining the bioavailability, which refers to the fraction of the administered drug that reaches the systemic circulation. This knowledge aids in optimizing drug delivery systems and ensuring consistent therapeutic outcomes.
3. Drug-Drug Interactions: Biopharmaceutics explores the potential interactions between drugs and other substances, including food, beverages, and co-administered medications. Certain substances can affect drug absorption, metabolism, or excretion, leading to altered drug concentrations and therapeutic effects. By studying the biopharmaceutical properties of drugs, scientists can identify and manage potential drug interactions, ensuring patient safety and optimizing drug therapy.
4. Pharmacokinetics and Pharmacodynamics: Biopharmaceutics contributes to the understanding of drug pharmacokinetics (what the body does to the drug) and pharmacodynamics (what the drug does to the body). Pharmacokinetics involves the study of drug absorption, distribution, metabolism, and excretion (ADME), while pharmacodynamics focuses on the relationship between drug concentration and the resulting pharmacological effects. Biopharmaceutical principles help determine drug dosages, dosing intervals, and routes of administration to achieve desired therapeutic outcomes while minimizing adverse effects.
This document discusses bioavailability and methods for assessing it. Bioavailability refers to the rate and extent that an unchanged drug is absorbed and available at its site of action. It depends on pharmaceutical, patient, and route of administration factors. Methods for assessing bioavailability include plasma drug concentration-time profiles, urinary excretion studies, acute pharmacological response methods, and therapeutic response methods. The concept of equivalence is also introduced, which examines the relationship between different drug products.
Population pharmacokinetics is the study of the sources and correlates of variability in drug concentrations among individuals who are the target patient population receiving clinically relevant doses of a drug of interest
Therapeutic drug monitoring (TDM) involves measuring drug concentrations in patients' blood to optimize drug therapy. TDM is useful for drugs with a narrow therapeutic index, high inter-individual variability, or when the relationship between concentration and clinical effects is well established. The TDM process includes requesting the test with relevant clinical information, collecting a proper blood sample, measuring drug levels in the laboratory, interpreting the results clinically, and adjusting drug dosing regimen accordingly to maintain concentrations within the therapeutic range. TDM aims to maximize drug effectiveness while minimizing toxicity.
This document provides an overview of pharmacology concepts for paramedics performing interfacility transfers. It defines important pharmacological terms and concepts like pharmacokinetics, pharmacodynamics, and classifications of medications. It emphasizes that the most common reason for interfacility transfers is to administer or monitor medications outside of a typical paramedic drug box. Paramedics must have sound knowledge of pharmacology to safely transport patients who require medication administration or monitoring.
This document provides an overview of pharmacology concepts for paramedics conducting interfacility transfers. It defines important pharmacological terms and concepts like pharmacokinetics, pharmacodynamics, and the autonomic nervous system. It also lists the 18 classes of medications paramedics are authorized to administer during transfers, including anticoagulants, anticonvulsants, antihypertensives, and narcotics. The document stresses the importance of understanding medication administration and monitoring, checking for correct drugs and dosages, and being prepared to address any issues during transport.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
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2. PHARMACOKINETICS
• Pharmacokinetics is the science of the kinetics of drug
• absorption,
• distribution, and
• elimination (ie, metabolism and excretion).
• The description of drug distribution and elimination is often termed drug
disposition.
• Characterization of drug disposition is an important prerequisite for
determination or modification of dosing regimens for individuals and groups
of patients.
Phar533 Dr. Abdullah Rabba
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3. The study of pharmacokinetics
Experimental approach
development of biologic sampling
techniques,
analytical methods for the measurement of
drugs and metabolites,
procedures that facilitate data collection
and manipulation.
Theoretical approach
development of pharmacokinetic
models that predict drug disposition
after drug administration.
(Mathematics and computer
Techniques are heavily utilized)
Phar533 Dr. Abdullah Rabba
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4. BIOPHARMACEUTICS
• Biopharmaceutics examines the interrelationship of the
• physical/ chemical properties of the drug,
• the dosage form (drug product) in which the drug is given, and
• the route of administration
• on the rate and extent of systemic drug absorption.
Phar533 Dr. Abdullah Rabba
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6. • biopharmaceutics involves factors that influence:
• (1) the design of the drug product,
• (2) stability of the drug within the drug product,
• (3) the manufacture of the drug product,
• (4) the release of the drug from the drug product,
• (5) the rate of dissolution/release of the drug at the absorption site,
• (6) delivery of drug to the site of action,
Phar533 Dr. Abdullah Rabba
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7. • The study of biopharmaceutics is based on fundamental scientific principles
and experimental methodology.
• Studies in biopharmaceutics use both in vitro and in vivo methods.
• In vitro methods are procedures employing test apparatus and equipment
without involving laboratory animals or humans.
• In vivo methods are more complex studies involving human subjects or
laboratory animals
Phar533 Dr. Abdullah Rabba
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8. PHARMACODYNAMICS
• Pharmacodynamics is the study of the biochemical and physiological
effects of drugs on the body; this includes the
• mechanisms of drug action
• relationship between drug concentration and effect.
• A typical example of pharmacodynamics is how a drug interacts
quantitatively with a drug receptor to produce a response (effect).
Phar533 Dr. Abdullah Rabba
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9. PHARMACODYNAMIC EFFECT
• The pharmacodynamic effect, (the pharmacologic effect), can be therapeutic
and/or cause toxicity.
• For many drugs, the pharmacodynamic effect is dose/drug concentration related;
the higher the dose, the higher drug concentrations in the body and the more
intense the pharmacodynamics effect up to a maximum effect.
• It is desirable that side effects and/or toxicity of drugs occurs at higher drug
concentrations than the drug concentrations needed for the therapeutic effect.
• Unfortunately, unwanted side effects often occur concurrently with the therapeutic
doses.
Phar533 Dr. Abdullah Rabba
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10. CLINICAL PHARMACOKINETICS
• Clinical pharmacokinetics is the application of pharmacokinetic methods to
drug therapy in patient care.
• It involves a multidisciplinary approach to individually optimized dosing
strategies based on
• the patient’s disease state (e.g. renal, hepatic….)
• and patient-specific considerations (e.g. genetics)
• The study of pharmacokinetic differences of drugs in various population
groups is termed population pharmacokinetics (Sheiner and Ludden, 1992)
Phar533 Dr. Abdullah Rabba
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11. TDM
• Clinical pharmacokinetics is also applied to therapeutic drug monitoring
(TDM) for very potent drugs, such as those with a narrow therapeutic range,
in order to optimize efficacy and to prevent any adverse toxicity.
• monitoring plasma drug concentrations (e.g., theophylline) or by
• monitoring a specific pharmacodynamic endpoint such as prothrombin clotting
time (e.g., warfarin).
• Pharmacokinetic and drug analysis services necessary for safe drug
monitoring are generally provided by the clinical pharmacokinetic service
(CPKS). Some drugs frequently monitored are the aminoglycosides and
anticonvulsants. Other drugs closely monitored are those used in cancer
chemotherapy, in order to minimize adverse side effects
Phar533 Dr. Abdullah Rabba
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12. TOXICOKINETICS AND CLINICAL
TOXICOLOGY
• Toxicokinetics is the application of pharmacokinetic principles to the design,
conduct, and interpretation of drug safety evaluation studies (Leal et al,
1993) and in validating dose-related exposure in animals.
• Toxicokinetic data aid in the interpretation of toxicologic findings in animals
and extrapolation of the resulting data to humans. Toxicokinetic studies are
performed in animals during preclinical drug development and may
continue after the drug has been tested in clinical trials.
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13. • Clinical toxicology is the study of adverse effects of drugs and toxic
substances (poisons) in the body.
• The pharmacokinetics of a drug in an overmedicated (intoxicated) patient
may be very different from the pharmacokinetics of the same drug given in
lower therapeutic doses.
• At very high doses, the drug concentration in the body may saturate
enzymes involved in the absorption, biotransformation, or active renal
secretion mechanisms, thereby changing the pharmacokinetics from linear
to nonlinear pharmacokinetics.
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14. MEASUREMENT OF DRUG
CONCENTRATIONS
• Drug concentrations are an important element in determining individual or
population pharmacokinetics.
• drug concentrations are measured in biologic samples, such as
• milk,
• saliva,
• plasma,
• urine.
• others
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15. • Sensitive, accurate, and precise analytical methods are available for the
direct measurement of drugs in biologic matrices.
• chromatographic and mass spectrometric methods are most frequently
employed for drug concentration measurement,
• chromatography separates the drug from other related materials that may
cause assay interference and mass spectrometry allows detection of
molecules or molecule fragments based on their mass-to-charge ratio.
Phar533 Dr. Abdullah Rabba
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16. SAMPLING OF BIOLOGIC
SPECIMENS
• Invasive methods include sampling
• blood,
• spinal fluid,
• synovial fluid,
• tissue biopsy, or any biologic material that requires parenteral or surgical intervention
in the patient.
• noninvasive methods include sampling of
• urine,
• saliva,
• feces,
• expired air,
• or any biologic material that can be obtained without parenteral or surgical
intervention.
Phar533 Dr. Abdullah Rabba
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17. DRUG CONCENTRATIONS IN
BLOOD, PLASMA, OR SERUM
• Measurement of drug and metabolite concentrations (levels) in the
• blood,
• serum, or
• plasma
• is the most direct approach to assessing the pharmacokinetics of the drug in
the body.
Phar533 Dr. Abdullah Rabba
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19. PLASMA DRUG CONCENTRATION–
TIME CURVE
• As the drug reaches the systemic circulation, plasma drug concentrations
will rise up to a maximum if the drug was given by an extravascular route.
• Usually, absorption of a drug is more rapid than elimination.
• As the drug is being absorbed into the systemic circulation, the drug is
distributed to all the tissues in the body and is also simultaneously being
eliminated.
Phar533 Dr. Abdullah Rabba
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21. • The onset time corresponds to the time required for the drug to reach the
MEC.
• The intensity of the pharmacologic effect is proportional to the number of
drug receptors occupied, which is reflected in the observation that higher
plasma drug concentrations produce a greater pharmacologic response,
up to a maximum.
• The duration of drug action is the difference between the onset time and
the time for the drug to decline back to the MEC.
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22. • The therapeutic window is the concentrations between the MEC and the MTC.
• Drugs with a wide therapeutic window are generally considered safer than drugs with a
narrow therapeutic window.
• Sometimes the term therapeutic index is used. This term refers to the ratio between the
toxic and therapeutic doses.
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24. • peak plasma level (Cmax), is related to the dose, the rate constant for
absorption, and the elimination constant of the drug
• time for peak plasma level (Tmax) is the time of maximum drug concentration
in the plasma and is a rough marker of average rate of drug absorption
• area under the curve, or AUC The AUC is related to the amount of drug
absorbed systemically.
Phar533 Dr. Abdullah Rabba
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25. PHARMACOKINETIC MODELS
• Drugs are in a dynamic state within the body as they
• move between tissues and fluids,
• bind with plasma or cellular components, or
• are metabolized.
• The biologic nature of drug distribution and disposition is complex, and drug events
often happen simultaneously.
• Such factors must be considered when designing drug therapy regimens.
• The inherent and infinite complexity of these events requires the use of
mathematical models and statistics to estimate drug dosing and to predict the time
course of drug efficacy for a given dose.
Phar533 Dr. Abdullah Rabba
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26. PHARMACOKINETIC MODELS
• A model is a hypothesis using mathematical terms to describe quantitative
relationships concisely.
• The model predicts (estimates) certain kinetic parameters by the
proper selection and development of mathematical function(s) that
fit kinetic variables (experimental data).
• A pharmacokinetic function relates an independent variable to a
dependent variable.
Phar533 Dr. Abdullah Rabba
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27. • For example, a pharmacokinetic model may predict the drug
concentration in the liver 1 hour after an oral administration of a 20-mg dose.
• The independent variable is time and the dependent variable is the drug
concentration in the liver.
• Such mathematical models can be devised to simulate the rate processes of
drug absorption, distribution, and elimination to describe and predict drug
concentrations in the body as a function of time.
Phar533 Dr. Abdullah Rabba
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28. • Simplifying assumptions are made in pharmacokinetic models to describe a
complex biologic system concerning the movement of drugs within the
body.
• For example, most pharmacokinetic models assume that the plasma drug
concentration reflects drug concentrations globally within the body.
Phar533 Dr. Abdullah Rabba
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29. • Pharmacokinetic models are used to:
1. Predict plasma, tissue, and urine drug levels with any dosage regimen
2. Calculate the optimum dosage regimen for each patient individually
3. Estimate the possible accumulation of drugs and/or metabolites
4. Correlate drug concentrations with pharmacologic or toxicologic activity
5. Evaluate differences in the rate or extent of availability between formulations
(bioequivalence)
6. Describe how changes in physiology or disease affect the absorption,
distribution, or elimination of the drug
7. Explain drug interactions
Phar533 Dr. Abdullah Rabba
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30. PHARMACOKINETIC MODELS
A model may be:
1. Empirically based:
Simply interpolates the data and allows an empirical formula to
estimate drug level over time (justified when limited information is
available).
Empirical models are practical but not very useful in explaining the
mechanism of the actual process by which the drug is absorbed,
distributed, and eliminated in the body.
Phar533 Dr. Abdullah Rabba
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31. 2. Physiologically based models:
Requires tissue sampling.
Requires monitoring organ blood flow.
Used in describing drug distribution in animals (tissue samples are
easily available for assay)
Has limitations to its use in humans.
Phar533 Dr. Abdullah Rabba
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32. 3. Compartmentally based models:
Very simple and useful tool in pharmaco-kinetics.
For example, assume a drug is given by intravenous injection and
that the drug dissolves (distributes) rapidly in the body fluids.
Phar533 Dr. Abdullah Rabba
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33. COMPARTMENTALLY BASED
MODELS:
• A model that can describe this situation is a tank containing a volume of
fluid that is rapidly equilibrated with the drug.
• The concentration of the drug in the tank after a given dose is governed by
two parameters:
(1) the fluid volume of the tank that will dilute the drug.
(2) the elimination rate of drug per unit of time.
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34. COMPARTMENTALLY BASED
MODELS:
Because a model is based on a hypothesis, a certain degree of caution is
necessary when relying totally on the pharmacokinetic model to predict
drug action.
For some drugs, plasma drug concentrations are not useful in predicting
drug activity.
For other drugs, an individual's genetic differences, disease state, and the
compensatory response of the body may modify the response of a drug.
Phar533 Dr. Abdullah Rabba
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35. • A compartment is not a real physiologic or anatomic region but is
considered as a tissue or group of tissues that have similar blood flow
and drug affinity.
• Within each compartment, the drug is considered to be uniformly
distributed.
• Mixing of the drug within a compartment is rapid and homogeneous
and is considered to be "well stirred,"
• so that the drug concentration represents an average concentration,
and each drug molecule has an equal probability of leaving the
compartment.
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36. Rate constants are used to represent the overall rate processes of drug
entry into and exit from the compartment.
The model is an open system because drug can be eliminated from the
system.
A compartmental model provides a simple way of grouping all the tissues
into one or more compartments where drugs move to and from the central
or plasma compartment.
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37. MAMMILLARY MODEL
• A compartmental model provides a simple way of grouping all the tissues into one
or more compartments where drugs move to and from the central or plasma
compartment.
The mammillary model is the most common compartment model used in
pharmacokinetics.
The mammillary model is a strongly connected system, because one can estimate
the amount of drug in any compartment of the system after drug is introduced into
a given compartment.
The mammillary model consist of one or more compartments around a central
compartment like satellites.
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38. MAMMILLARY MODELS
One-compartment model:
Drug is both added to and eliminated from a central compartment.
The central compartment is assigned to represent plasma and highly perfused
tissues that rapidly equilibrate with drug.
When an intravenous dose of drug is given, the drug enters directly into the central
compartment.
Elimination of drug occurs from the central compartment because the organs
involved in drug elimination, primarily kidney and liver, are well-perfused tissues.
Phar533 Dr. Abdullah Rabba
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40. MAMMILLARY MODELS
Two-compartment model:
drug can move between the central or plasma compartment to and from
the tissue compartment.
The total amount of drug in the body is simply the sum of drug present in
the central compartment plus the drug present in the tissue compartment.
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42. PHYSIOLOGIC PHARMACOKINETIC
MODEL (FLOW MODEL)
The model would potentially predict realistic tissue drug concentrations,
which the two-compartment model fails to do.
Much of the information required for adequately describing a physiologic
pharmacokinetic model are experimentally difficult to obtain.
In spite of this limitation, the physiologic pharmacokinetic model does
provide much better insight into how physiologic factors may change drug
distribution from one animal species to another.
Phar533 Dr. Abdullah Rabba
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