Question

2. In one compartment model with bolus dose in PK model, derive equation for concentration (C),...

2. In one compartment model with bolus dose in PK model, derive equation for concentration (C), half-life (t1/2), and clearance (ke) from mass-balance equation.

Homework Answers

Answer #1

one compartment model with bolus dose in PK model is first order reaction

ke = elimination rate constant

Mass balance equation

Initial rate of dose available in body - rate of dose out = rate of change of dose with time

0 - ke*X = dX/dt

dX/dt = - ke*X

Relation between dose amount (X) and concentration of plasma (C)

X = C*V

V = Apparent volume of distribution

dX/dt = - ke*X

d(C*V) /dt = - ke*(C*V)

dC/dt = - ke*C

dC/C = - ke*dt

Integrate the equation

Initial concentration (at time t = 0) = Co

Final concentration (at time t = t) = C

ln (C/Co) = - ke*t

Half life (t1/2) is when the final concentration C = Co/2

ln [C/(C/2)] = - ke*t1/2

ln 2 = - ke*t1/2

t1/2 = - 0.6932 / ke

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Half-life equation for first-order reactions: t1/2=0.693k   where t1/2 is the half-life in seconds (s), and kis...
Half-life equation for first-order reactions: t1/2=0.693k   where t1/2 is the half-life in seconds (s), and kis the rate constant in inverse seconds (s−1). a) What is the half-life of a first-order reaction with a rate constant of 8.10×10−4  s^−1? Express your answer with the appropriate units. b) What is the rate constant of a first-order reaction that takes 151 seconds for the reactant concentration to drop to half of its initial value? Express your answer with the appropriate units. c) A...
The integrated rate law allows chemists to predict the reactant concentration after a certain amount of...
The integrated rate law allows chemists to predict the reactant concentration after a certain amount of time, or the time it would take for a certain concentration to be reached. The integrated rate law for a first-order reaction is: [A]=[A]0e−kt Now say we are particularly interested in the time it would take for the concentration to become one-half of its initial value. Then we could substitute [A]02 for [A] and rearrange the equation to: t1/2=0.693k This equation calculates the time...
A liter of pH 7.20 phosphate buffer is needed for a certain experiment. The Henderson-Hasselbach equation...
A liter of pH 7.20 phosphate buffer is needed for a certain experiment. The Henderson-Hasselbach equation will be sufficiently accurate for your determination of pH. The pK’s for possibly relevant phosphate species are: H3PO4 ↔ H2PO4- + H+ pK = 2.15 H2PO4- ↔ HPO4-2 + H+ pK = 7.20 HPO4-2 ↔ PO4-3 + H+ pK = 12.4 0.100 Moles of H3PO4 were dissolved in about 800 mL of water, and the pH was adjusted to 7.20 using a standardized pH...
1. Which of the following ranks as one of the most important factors governing drug disposition?...
1. Which of the following ranks as one of the most important factors governing drug disposition? a. Bioavailability b. Volume of distribution c. Clearance d. Elimination half-life (t1/2) e. All of the above 2.. Carbon monoxide might be present in an individual’s blood from which of the following? a. The metabolism of dihalomethanes such as methylene chloride b. Cigarette smoke c. The exhaust from internal combustion machines d. Malfunctioning heating and ventilation systems e. All of the above 3. Acetaminophen...
(25 pts) You construct an organ-on-a-Chip (OOC) system to model an organ so you can evaluate...
(25 pts) You construct an organ-on-a-Chip (OOC) system to model an organ so you can evaluate different drugs for a pharmaceutical company. The chip allows injection of the organ chamber with a constant volumetric flow rate (Q) from one side and leaks through a membrane from the other side with a leak rate constant, k1 to model drug administration and adsorption. Create and solve a single compartment model of the OOC. a. (5 pts) Sketch a single compartmental model of...
Suppose the following model of government efficiency. Utility function over consumption of private goods (C) and...
Suppose the following model of government efficiency. Utility function over consumption of private goods (C) and public goods (G) U(C,L) = C^0.5G^0.5 Exogenous Income: Y = 50 Lump-sum tax: T Budget constraint: C + T = Y PPF: C = Y – G/q Government efficiency: q = 0.8 (This measures the number of public goods that can be produced from one unit of private consumption good) We want to maximize the representative consumer’s utility and balance the government budget. Find...
Elementary principles of chemical engineering 4th edition problem 10.17 A tracer is used to characterize the...
Elementary principles of chemical engineering 4th edition problem 10.17 A tracer is used to characterize the degree of mixing in a continuous stirred tank. Water enters and leaves the mixer at a rate of V(dot)m3/min. Scale has built up on the inside walls of the tank, so that the effective volume Vm3 of the tank is unknown. At time t =0, a mass m0kg of the tracer is injected into the tank and the tracer concentration in the outlet stream,...
Many houses in the Washington area experience indoor air pollution by radon. A house of a...
Many houses in the Washington area experience indoor air pollution by radon. A house of a volume V = 300 m3 has air leaking in from the soil with a radon concentration of 5000 pCi/L and rate of 20 L/h. During the winter time, the average rate of fresh radon-free air entering the house is only 400 L/h. Radon undergoes decay following a first order reaction with a rate constant k = 0.18/day. The house can be approximated as a...
Cholera and other diarrheal diseases cause nearly 2 billion cases of diarrhea annually. Cholera toxin and...
Cholera and other diarrheal diseases cause nearly 2 billion cases of diarrhea annually. Cholera toxin and other bacterial toxins cause the intestine to secrete fluid into the lumen of the gut, depleting the extracellular fluid (ECF) volume. If fluid loss is not matched with fluid intake (law of mass balance), the result is severe dehydration, circulatory collapse, and even death. Drinking a rehydration solution is the most rapid and effective way to replace the large volumes of water lost by...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT