The One compartment open model treats the body as one homogeneous volume in which blending is quick and where info and yield are from this one volume. The one-compartment open model is the least difficult approach to depict the procedure of medication appropriation and end in the body and this model accept that the medication can enter or leave the body and the whole body acts like a solitary, uniform compartment. The least complex pharmacokinetic model that portrays medicate manner in the body is the IV bolus model where the medication is infused at the same time into a container which is the human body or compartment and where the medication circulates/equilibrates momentarily and quickly all through the compartment. Again the easiest course of medication organization from a demonstrating point of view is a quick intravenous infusion (IV bolus). Medication end from the compartment likewise starts to happen following the IV bolus infusion.

1. ANUPAM SAHA
SUNIRMAL BHATTACHARJEE
Email ID - sunirmal.pharma@gmail.com
PHARMACOKINETIC- ONE
COMPARTMENT MODELING

2. INTRODUCTION:
• Pharmacokinetics
• Clinical pharmacokinetics
• Compartments

3. BASIC PRINCIPLE OF PHARMACOKINETICS

4. One Compartment Open Model
• Physiologically based pharmacokinetic (PBPK)modeling is a
mathematical modeling technique for predicting the absorption,
distribution, metabolism and excretion (ADME) of synthetic or natural
chemical substances in humans and other animal species. This is
called pharmacokinetic model.
• Pharmacokinetic models are developed based on certain
assumptions. It should be remembered that application of mathematic
to physiological events means to correlate mathematics with
physiological events , so assumption made should be realistic and
practical.

5. The following assumptions
are : -
– The process of drug absorption from the absorption site may be
explained by the first order kinetics.
– Once a drug enters the systemic circulation, it rapidly distributes to other
body fluids and tissue , and a dynamic equilibrium is achieved
instantaneously between the drug in the blood and the drug in other
tissues.
– Any changes that occur in the plasma levels of a drug reflects
proportional changes in the tissue drug level.
– Elimination in the drug from body follows an apparent first order rate
constant.

6. • ZERO ORDER KINETICS
Zero order Half- Life
t1/2 = C0 /2K0
• FIRST- ORDER KINETICS
First-Order Half-Life
• Mixed-Order Kinetics
t1/2 = o.693/K
dC/dt = K0C0 =-K0

7. PHARMACOKINETIC MODELS
• Compartment model
Mammiliary model
Caternary model
• Noncompartmental model
• Physiologic model

8. COMPARTMENT MODELING
ONE COMPARTMENT OPEN MODEL
•Intravenous bolus administration
•Intravenous infusion
• Extravascular administration
A) Extravascular administration zero order
B) Extravascular administration first order
• Disposition as viewed from urine

9. INTRAVENOUS BOLUS ADMINISTRATION
dX/dt = Rate in (availability) – Rate out (elimination)
dX/dt = - KE X

10. • Elimination Rate Constant
KE= Km + Ke
Pharmacokinetic parameters
dX/dt = - KE X
Integration
lnX = lnX0 – KE t
X = X0 e-Ket
logX = logX0 – KEt / 2.303 logC = logC0 – KEt / 2.303

11. • Elimination Half-Life
• Apparent Volume of Distribution

12. • AUC Estimation
X0 = Ke Vd AUC
• Clearance
• Total Body Clearance
ClT = ClR + ClNR
𝑉𝑑 =
𝑋0
𝐾𝑒 (𝐴𝑈𝐶)

13. One Compartment Open Model – Intravenous
continuous infusion
= R0 - KEX
Integration

14. Loading Dose Plus IV Infusion
XO,L = CSSVd
XO,L =

15. Extravascular Administration
>
=
<

16. Urinary Excretion Data
• Useful when there is a lack of sensitive analytical
technique
• It is more convenient
• Less sensitive analytical method required
• Direct measurement of bioavailability
• CLR =

17. References
• Ali j.et al (2004) “Biopharmaceutics and Pharmacokinetics” 2nd ed. Birla Publications Pvt. Ltd.
Delhi, 64-115
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2nd ed. Vallabh Prakashan, Delhi p.p. 235-298
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2012]
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stark.pdf> [Accessed 24-8-2012]

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clearer) [Online] Available at<http://www.cop.ufl.edu/wp-content/uploads/ 2010
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Pharmacokinetics” 2nd ed. 2003 Nirali Prakashan India 61-92
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• Available <http://www.sciencedirect.com/science/article/pii/S 0304401705002591&d
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