Trapezoid method and bioavailability
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1. Bioavailability is defined as the extent and rate at which the active drug ingredient is delivered to systemic circulation from the dosage form. It is calculated using pharmacokinetic methods. 2. For calculation of bioavailability, blood samples are taken and the drug concentration in blood plasma is evaluated over time to generate a plasma concentration-time graph. The area under the curve (AUC) is calculated using the trapezoid rule to sum the areas of individual trapezoids under the curve. 3. The absolute bioavailability is calculated as the AUC for the oral dose divided by the AUC for an equivalent intravenous dose, both adjusted for their respective doses. This provides the percentage of oral drug dose that reaches systemic circulation
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ONE COMPARTMENT OPEN MODEL I.V BOLUS (Contact me: dr.m.bharathkumar@gmail.com)
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The document appears to be a scanned receipt from a grocery store listing various food and household items purchased totaling $123.45. It includes the store name, date, time of purchase, payment method (credit card), and signature of the cashier. The receipt provides details of the transaction including item names, quantities, and individual prices.Excretion renal and non-renal
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Biopharmaceutics and Pharmacokinetics Practical Manual
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- How drugs distribute between compartments according to first-order rate constants K12 and K21, and are eliminated from the central compartment at a rate of KE
- Equations that describe drug concentrations in each compartment over time after intravenous or oral administration
- Methods for determining pharmacokinetic parameters like absorption rate constant Ka, distribution and elimination rate constants, and compartment volumes from drug concentration-time data.
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ONE COMPARTMENT OPEN MODEL I.V BOLUS (Contact me: dr.m.bharathkumar@gmail.com)
ONE COMPARTMENT OPEN MODEL I.V BOLUS (Contact me: dr.m.bharathkumar@gmail.com)DR. METI.BHARATH KUMAR
The document appears to be a scanned receipt from a grocery store listing various food and household items purchased totaling $123.45. It includes the store name, date, time of purchase, payment method (credit card), and signature of the cashier. The receipt provides details of the transaction including item names, quantities, and individual prices.Excretion renal and non-renal
This document discusses renal and non-renal routes of drug excretion. It describes the key organs and processes involved in excretion, including the nephron in renal excretion and factors that determine if a drug is excreted renally or non-renally. Non-renal excretion includes biliary excretion through the liver and bile ducts. Clearance, excretion ratio, and other pharmacokinetic concepts relating to measurement of excretion are also covered.
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This document discusses multiple-dose drug regimens and factors that influence their design. It begins by explaining that multiple doses are needed to maintain drug levels within the therapeutic window between the minimum effective concentration and maximum tolerated concentration. The dosage regimen must provide these levels without excessive fluctuation.
It then outlines criteria for an optimal regimen, including maintaining levels within the therapeutic range and dosing convenience. Factors like dose size and dosing frequency influence the regimen design. The principle of superposition and concepts of drug accumulation, steady-state levels, and therapeutic indices are also introduced.
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ONE COMPARTMENT OPEN MODEL I.V BOLUS (Contact me: dr.m.bharathkumar@gmail.com)
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This document provides information about determining absorption and elimination rates using compartment models. It discusses what compartment models are and describes one-compartment open models. It explains zero-order and first-order absorption models and how to calculate elimination rate constants. The document also discusses using urinary excretion data to estimate pharmacokinetic parameters when plasma concentration data is unavailable. Parameters like volume of distribution, clearance, excretion and elimination rate constants can be estimated from urinary excretion data using methods like the rate of excretion method.
Determination of absorption and elimination rates on base of compartment model
This document provides information about determining absorption and elimination rates using compartment models. It discusses the concepts of absorption, elimination, and compartment models. It then describes the one-compartment open model and differences between zero-order and first-order absorption kinetics. The document outlines the absorption and elimination phases when following one-compartment kinetics. It also discusses using urinary excretion data to determine pharmacokinetic parameters when plasma level data is unavailable. The document was prepared by Abhinay Ashok Jha for his final year assessment on this topic.
Michaelis Menten Equation and Estimation Of Vmax and Tmax.pptx
Michaelis Menten Equation and Estimation Of Vmax and Tmax
Kinetika En 2002
- Pharmacokinetics is the study of the absorption, distribution, metabolism, and excretion of drugs in the body over time. It aims to quantitatively account for the amount of drug in the body and the rate it is cleared.
- Distribution of drugs throughout tissues is affected by factors like membrane permeability, blood flow, lipid solubility, pH, and plasma protein binding. The apparent volume of distribution indicates how much volume a drug appears to distribute into based on its concentration in plasma.
- Clearance is the rate of drug elimination from plasma relative to its concentration and depends on hepatic and renal elimination. It is used to calculate maintenance dosing to achieve a target concentration.
Kinetika En 2002
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.
Application of pharmacokinetics
This document discusses the design of dosage regimens and controlled release drug delivery systems based on pharmacokinetic principles. It begins with an introduction to pharmacokinetics and then covers factors to consider in designing dosage regimens such as dose size, dose frequency, and approaches like empirical or population-based modeling. It also discusses concepts like loading and maintenance doses, drug accumulation, and fluctuation for multiple dosing. Finally, it discusses using pharmacokinetic parameters to design controlled release formulations to optimize therapeutic effects and reduce side effects.
Calculate and Interpret Pharmacokinetic Parameters of a Given Drug
1. The document discusses pharmacokinetic parameters such as volume of distribution, clearance, elimination rate constant, and half-life that can be calculated from plasma drug concentration data over time following intravenous administration.
2. Formulas and step-by-step calculations are provided to determine these parameters from sample concentration-time data, including using linear regression of log-transformed or natural log-transformed concentration values.
3. Key pharmacokinetic parameters like half-life, initial concentration, volume of distribution, and total clearance are calculated for an example drug using the provided concentration data and formulas.
A seminar on one & two compartment open model extra vascular administration
A seminar on one & two compartment open model extra vascular administrationMalla Reddy College of Pharmacy
This document summarizes one and two compartment open models for extravascular drug administration. It describes how compartment models are used to simplify drug distribution and elimination processes in the body. A one compartment open model is presented, showing drug absorption from extravascular administration followed by distribution and elimination from the body compartment. Equations are provided to describe drug behavior under zero-order and first-order absorption. Methods for estimating the absorption rate constant like residuals and Wagner-Nelson are also summarized. Finally, a two compartment open model is briefly introduced.Aaditya- calculation of pk parameters
The document discusses the calculation of pharmacokinetic parameters which are used to quantitatively analyze the processes of drug absorption, distribution, and elimination in the body over time. It describes various pharmacokinetic models including non-compartmental and compartmental models as well as how parameters like volume of distribution, clearance, half-life and area under the curve are defined and measured. The models are used to predict the concentration of drugs in the body over time based on the processes of absorption, distribution, metabolism and excretion.
Consolidation parameters
This document discusses various parameters used to analyze drug release from pharmaceutical formulations, including diffusion parameters, dissolution parameters, pharmacokinetic parameters, and several kinetic models. It provides details on Higuchi's model, Peppas plot, zero order, first order, and Hixson Crowell models. These models are used to characterize drug release from modified release formulations and determine the drug release mechanism.
one compartment open model
This document discusses the one compartment open model for intravenous bolus administration of drugs. It describes the body as a single uniform compartment and examines the elimination of drugs from this compartment over time. The key pharmacokinetic parameters discussed are the elimination rate constant, apparent volume of distribution, elimination half-life, and clearance. Equations for calculating the elimination rate constant and apparent volume of distribution using data from intravenous bolus doses are also presented.
Sandeep ppt
The document discusses protein binding kinetics, bioequivalence studies, and non-compartmental analysis. It describes protein-drug binding and how bound drug is pharmacologically inert. It discusses different plots used to determine protein binding constants and sites. It defines types of equivalence studies and describes in vivo and in vitro study designs. It outlines bioequivalence protocol components and discusses alternate study designs. Finally, it explains non-compartmental analysis which determines pharmacokinetic parameters without compartment models.
TOXICOKINETICS
This document discusses toxicokinetics, which refers to applying pharmacokinetic principles to understand toxicity and adverse effects of drugs and chemicals. It covers several key concepts:
1. Toxicokinetic studies examine systemic exposure after dosing at toxic levels, helping assess safety, while pharmacokinetic studies use lower doses.
2. Models describe the time course of a chemical in the body, including one-compartment open models and multi-compartment models accounting for tissue distribution.
3. Key parameters include volume of distribution, clearance, half-life and how they relate through equations. Non-linear toxicokinetics can occur at high doses due to enzyme saturation.
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PHARMACOKINETICS: BASIC CONSIDERATION & PHARMACOKINETIC MODELS
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Calculation of various pharmacokinetics parameters after IV Bolus injection.pdf
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Determination of absorption and elimination rates on base of compartment model
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Trapezoid method and bioavailability
- 2. 08/12/18BHARDWAJ CLASS 2 BIOAVAILABILITY = BIO (IN BLOOD) + AVAILABILITY (AMOUNT/EXTENT OF DRUG IN BLOOD) Bioavailability is defined as the EXTENT (AMOUNT) and the RATE (MAY BE FIRST ORDER OR ZERO ORDER) at which the ACTIVE INGREDIENT (unchanged form of drug or active molecules) is delivered To The Systemic Circulation (IN PLASMA/BLOOD)from the dosage form(or from absorption site). HOW ? WHY ?
- 3. FOR CALCULATION OF BIOAVAILABILITY WE USED PHARMACOKINETICS AND PHARMACODYNAMICS METHOD .
- 4. For calculation of bioavailability we take blood sample and evaluate the concentration of drug in blood plasma. (EXTENT/AMOUNT OF TOTAL DRUG IN BLOOD) FOR THIS WE USED TRAPEZOID RULE. BLOOD PLASMA METHOD Area of Trapezoid = a (b+c/2) WHAT IS TRAPEZOID? b c a TRAPEZOID
- 5. S.N O. TIME (IN MIN) PLASMA DRUG CONCENTRAT ION (MG/ML) 0 0 t0 0 C0 1 t1 C1 2 t2 C2 3 t3 C3 4 Plot the graph between plasma drug concentration and time. Cmax Tmax
- 6. METHOD 1.Plot the graph between plasma drug concentration vs. time. 2.For calculation of bioavailability calculate the AUC(area under the curve). 3.For AUC calculation break the total graph into small trapezoid area and calculate the area of trapezoid. For example :- according to above figure the AUC of single trapezoid is Area of Trapezoid = a (b+c/2) where a is time on x axis and b,c is concentration on y axis.
- 7. 4. Calculate the total AUC of graph is 5.Now calculate the Area 2, AREA 3, AREA 4, AREA 5 ,AREA 6,AREA 7 AUC OF GRAPH = Area 1+Area 2+Area3+Area 4+Area 5+Area 6+Area 7+ C*/K (AUC)0 t (AUC)t ∞ 6 Here C*/K = Last observed plasma drug concentration/overall elimination rate constant.
- 8. K = OVERALL ELIMINATION RATE CONSTANT. For calculation of K we used i.v.bolus one compartment open model equation. from this equation K/2.303 = SLOPE = LOG Y1-LOG Y2 / X2-X1 From this equation we calculate the log value of PDC(Plasma drug concentration) and plot the graph between Log PDC VS TIME. Select any two point from the graph and calculate the slope.
- 9. S.No. Pharmacokinetic Factor Name Result 1 Maximum plasma drug concentration (Cmax) Peak of graph 2 Time at Maximum plasma drug concentration (tmax) Time at Cmax 3 (AUC)0 t 4 (AUC)t ∞ The Absolute Bioavailability = AUC (Oral) × Dose (IV) AUC (IV) × Dose (Oral) RESULT – From the above study the following data was obtained –