Biopharmaceutics math quiZ

 

A 70-kg volunteer is given an intravenous dose of antibiotic, and serum drug concentrations were determined at 1 hour and 6 hours after administration. The drug concentrations were 4.2 and 0.4 mg/L, respectively. What is the half-life for this drug, assuming first-order elimination kinetics?

a. 1.2 hours
b. 1.5 hours
c. 2.5 hours
d. 4.0 hours
e. 6.2 hours

B

After the administration of a single IV dose (500 mg) of theophylline to a patient, the drug amount-time profile in this patient was described by the following equation:
lnC = lnCo - 0.115 * t where t= time in hours.
What is half-life of theophylline in this patient (hr)?

A) 5
B) 6
C) 7
D) 8

B

After the administration of a single IV dose (500 mg) of theophylline to a patient, the drug amount-time profile in this patient was described by the following equation:
lnC = lnCo - 0.115 * t where t= time in hours.
What will be the percentage of theophylline left in the body after 10 hr of administration?

A) 32 %
B) 58 %
C) 68 %
D) 50%
E) 90%

A

A drug has an elimination t1/2 of 10 hours and follows zero-order kinetics. If a single 50-mg dose is given to an adult male patient by IV bolus injection, what percent of the dose is lost in 14 hours?

A) 35%
B) 70 %
C) 85%
D) 94%
E) 15 %

B

A solution of a drug was freshly prepared at a concentration of 300 mg/mL. After 30 days at 25oC, the drug concentration in the solution was 75mg/mL.
Assuming first-order kinetics, when will the drug decline to one-half of the original concentration?

A.10 days
B.15 days
C.20 days
D.25 days
E.30 days

B

If the amount of drug in the body declines from 100% of the dose (IV bolus injection) to 25% of the dose in 8 hours, what is the elimination half-life for this drug? (Assume first-order reaction).

A) 0.173 hour
B) 0.75 hours
C) 2 hours
D) 4 min
E) 240 min

No Answer

A new antibiotic drug was given in a single intravenous bolus of 4 mg/kg to five healthy male adults ranging from 23-38 years (average weight 75 kg). Answer the following using the equation Cp = 78e-0.46t (assume units of μg/mL for Cp and hour for t)

a) How much of the drug is left in the body if after 4 Hours?


b) Assuming the drug is no longer effective when the levels decline to less than 2 μg/mL, when should you administer the next dose?

a) 12.4 μg/mL
b) 8 hr (1 decimal place)

A single IV injection containing 500 mg of cefamandole nafate is given to an adult female patient (63 years, 55 kg) for a septicemic infection. The volume of distribution is 0.1L/Kg and the elimination half-life is 0.75 hour. Assuming the drug is eliminated by first-order kinetics, calculate the following:
a) The initial plasma concentration (Cp)?

b) The amount of the drug in the body 4 hours after the dose is given?

c) The time for the drug to decline to 0.5 ug/mL, the minimum inhibitory concentration for streptococci?

a) The initial plasma concentration (Cp) = 90.9 mg/L

b) The amount of the drug in the body 4 hours after the dose is given = 12.3 mg

c) The time for the drug to decline to 0.5 ug/mL, the minimum inhibitory concentration for streptococci. = 5.6 hr

Bioavailability data are used to determine all of the following except:

a. The relationship between drug blood levels and clinical efficacy and toxicity
b. The amount or proportion of drug absorbed from the dosage form
c. The duration of the drug's presence in the biologic fluid or tissue correlated with the patient's response
d. The palatability of a drug in different dosage
e. The rate at which the drug is absorbed

D

Which of the following are factors that a pharmacist must consider when determining a dosage regimen for a specific patient? (Select all that apply)

a. Pharmacodynamics and toxicity of the drug
b. Clinical state of the patient
c. Pharmacokinetics of the drug
d. How the patient will be managed

A,B,C,D

The rate constant k1 for the decomposition of 5-hydroxymethylfurfural at 120°C (393 K) is 1.173 hr−1 and k2 at 140°C (413 K) is 4.860 hr−1.

What is the activation energy, Ea, in kcal/mole?

23 kcal/mole

Reconstituted ampicillin suspension is stable for 16 days (shelf-life) when stored in the refrigerator (5°C). If the product is left at room temperature (25°C), what is the reduction in the expiration dating? Use a Q10 value of 3.

14 days

An ophthalmic solution of a mydriatic drug at 5 mg/mL exhibits first-order degradation with a rate of 0.0005/d. How long will it take for the drug to degrade to 90% of its original concentration?

211 days

An ophthalmic solution has a shelf life of 24 hours at room temperature (25°C). What is the estimated shelf life in a refrigerator at 8°C? Use a Q10 value of 3.

155 hrs

An antibiotic solution has a shelf life of 48 hours in the refrigerator (4°C). What is its estimated shelf life at room temperature (28°C)? Use a Q10 value of 3

3.4 hrs

A drug solution has a shelf life of 90 days in the refrigerator (28°C). What is its estimated shelf life at room temperature (28°C)? Use a Q10 value of 3

90 days

Which of the following is not a method of sterilization of dosage forms?

a. Centrifugation
b. Dry heat
c. Autoclave
d. Irradiation
e. Filtration

A

Which of the following are modes of action of preservatives of some dosage forms (Select all that apply):

a. Oxidation of cellular constituents
b. Modification of cell membrane permeability
c. Lysis and cytoplasmic leakage
d. Irreversible coagulation of cytoplasmic constituents
e. Inhibition of cellular metabolism

A,B,C,D,E

Which of the following is not a Compendia Requirements for Capsules?
a) Containers for dispensing capsules
b) Disintegration test for capsules
c) Dissolution test for capsules
d) Weight variation
e) Content formation

E

For each active ingredient, the amount required to make 30 capsules is

Diphenhydramine HCl (750 mg)
Phenyltoloxamine citrate (900mg)
Acetaminophen (9.75g)

Weight of 1 capsule full of Lactose = 475 mg

Weight of 1 capsule full of Diphenhydramine HCl = 400 mg

Weight of 1 capsule full of Phenyltoloxamine citrate = 375 mg

Weight of 1 capsule full of Acetaminophen = 425 mg

Determining the Amount of Lactose Required for making prescription for one capsule:

44 mg

Which of the following powders is most likely to liquefy upon absorption of moisture?
a. Efflorescent
b. Hygroscopic
c. Deliquescent
d. Dusting
e. Dusting and Hygroscopic

C

All of the following may occur during Phase 1 clinical trials of a prospective new drug except:


A.
Testing in human beings for drug safety

B.
Testing in human beings for drug effectiveness

C.
Evaluating side effects associated with increasing doses

D.
Selecting from among different chemical analogs of a lead compound

B

What is the concentration of drug remaining in systemic circulation after 4 hr, if the initial concentration is 16.2 mg/L and elimination rate constant (Kel) is 0.2 hr-1? (Assume the first-order process).


A.
7.27


B.
9.58

C.
12.24

D.
15.92

E.
25

A

If the amount of drug in the body declines from 100% of the dose (IV bolus injection) to 25% of the dose in 8 hours, what is the elimination half-life for this drug? (Assume first-order reaction).

A.
0.173 hour

B.
0.75 hour

C.
2 hours
D.
4 mins

E.
240 mins

E

A drug has an elimination t1/2 of 6 hours and follows first-order kinetics. If a single 200-mg dose is given to an adult male patient by IV bolus injection, what percent of the dose is lost in 24 hours? (Assuming is first order kinetics)


A.
54

B.
75

C.
85

D.
94

E.
100

D

All of the following pharmaceutical items are subject to regulation by cGMP except:


A.
Heparin prefilled syringes

B.
Implantable insulin infusion pumps

C.
Peptides produced by recombinant DNA technology

D.
None of the above

D

Toxicological profiles for drugs include all of the following except:




A.
Carcinogenicity

B.
Drug efficacy

C.
Chronic adverse effect

D.
Reproduction studies

E.
Genotoxicity or mutagenicity studies

B

Which of the following are appropriate compounding practices? Preparation of components into formulation: (Select all that apply).



A.
For the purpose of research or teaching

B.
For chemical analysis and not for sale or dispensing

C.
For a patient as the result of a prescription drug order

D.
For resale by other local pharmacies

E.
In the limited amounts in anticipation of receiving prescription drug order

A,B,C,E

All of the following are physical-chemical factors that favor the diffusion of a drug across mammalian membranes except:


A.
The unionized form of the drug

B.
Hydration of ionized drugs

C.
Small particles size

D.
Large concentration gradient

E.
Lipid solubility

B

All of the following statements are true regarding drug metabolism except:


A.
May take place in the liver, kidney, lungs, and gastrointestinal tract

B.
Involves the biochemical transformation of drug substance

C.
Some new drugs have been discovered as metabolites of other processes

D.
Specific and nonspecific enzymes participate in the metabolic process

E.
Metabolites of the administered drug never have pharmacologic activity

E

In which of the following phases of clinical testing is the final formulation usually developed?



A.
Phase 3

B.
Phase 1

C.
Phase 4

D.
Phase 2

D

Which of the following is the legal source of cGMPs requirements for FDA-approved human and animal drugs?


A.
The USP

B.
The FDA Compliance Policy Guide

C.
The Code of Federal Regulations

D.
The Federal Register

C

Which of the following are factors that a pharmacist must consider when determining a dosage regimen for a specific patient? (Select all that apply)




a. Half-life

B.
Clinical state of the patient
C.
How the patient will be managed

D.
Pharmacodynamics and toxicity of the drug

ALL

What is initial concentration of drug if the drug concentration remaining in blood is 7.8 mg/L after 8 hr and half-life is 2.475 hr? (Assume first order kinetics)

A.
20.5

B.
31. 3

C.
52.67

D.
73.26

E.
83.78

D