Question 1
In vitro determination of bioavailability by dissolution rate is not the best way to determine therapeutic efficacy.
A. True
B. False
View Answer
Answer: Option B
Explanation:
Physicochemical property of most of the drugs that have the greatest influence on their absorption characteristics from the gastrointestinal tract is dissolution rate. To assess the therapeutic efficacy of slow dissolving drugs is in vivo determination of bioavailability. It is done whenever a new formulation is to be introduced in the market.
Question 2
Multiple dose study is better since we can understand the peak, valley, drug blood levels, etc.
A. True
B. False
View Answer
Answer: Option A
Explanation:
Multiple dose study is difficult to control since it exposes the subject to a higher level of drug which is dangerous sometimes. This method is very tedious and time-consuming. The advantages of such method are accurately reflected how the drug should be used, easy to predict peak and valley of a drug, can be ethically performed on the patient, better evaluation of the performance of controlled release formulation is possible.
Question 3
Single-dose bioavailability studies are simple and common.
A. True
B. False
View Answer
Answer: Option A
Explanation:
Single-dose bioavailability studies are common, easy, offer less exposure to drugs and are less tedious. Although it is difficult in a single dose bioavailability study to predict the steady-state characteristics of a drug and inter-subject variability. Multiple dose study is difficult to control.
Question 4
Therapeutic response is based on observing the clinical response to a drug formulation.
A. True
B. False
View Answer
Answer: Option A
Explanation:
Therapeutic response is based upon the clinical responses to a drug formulation given to patients suffering from the disease for which the drug should be used. A drawback of the method is the quantification of observed response is not proper to allow for assessment of relative bioavailability between dosage forms of the same drug.
Question 5
What is the equation for bioavailability?
A. [AUC]std Dstd τtest / [AUC]test Dtest τstd
B. [AUC]test Dtest τstd / [AUC]std Dstd τtest
C. [AUC]test Dstd τtest / [AUC]std Dtest τstd
D. 1 / [AUC]std Dtest τstd
View Answer
Answer: Option C
Explanation:
The equation of bioavailability is [AUC]test Dstd τtest / [AUC]std Dtest τstd, D stands for dose administered, test and std indicate the test and standard doses of the same drug to determine the relative availability. The dosing interval is τ.
Question 6
What is the equation of bioavailable fraction?
A. 1/Bioavailable dose
B. 1/Administered dose
C. Bioavailable dose/Administered dose
D. Administered dose/Bioavailable dose
View Answer
Answer: Option C
Explanation:
The amount of drug that reaches the systemic circulation is known as systemic bioavailability. The bioavailable fraction F refers to the fraction of administered dose that enters the systemic circulation after drug administration. The equation is F = Bioavailable dose/Administered dose.
Question 7
The urinary excretion of the unchanged drug is directly proportional to the plasma concentration of a drug.
A. True
B. False
View Answer
Answer: Option A
Explanation:
Urinary excretion studies help in assessing bioavailability is based on the principle that urinary excretion of unchanged drug is directly proportional to the plasma concentration of a drug. If a drug is excreted at least 10 to 20% in the urine, bioavailability can be determined.
Question 8
What is bioavailability?
A. The time of absorption of the drug from its dosage form
B. The rate of absorption of the unchanged drug from its dosage form
C. The time of absorption of the unchanged drug from its dosage form
D. The rate of absorption of the drug from its dosage form
View Answer
Answer: Option B
Explanation:
Physiologic availability, biologic availability or just bioavailability is defined as the rate or the amount of absorption of an unchanged drug from its dosage form. The rate with which the drug is getting absorbed is important since in some treatment such as asthma attack rapid onset action is required.
Question 9
Which of the following is not an important parameter of plasma level time studies?
A. Cmax
B. Tax
C. The area under the plasma level-time curve
D. Steady state level
View Answer
Answer: Option D
Explanation:
Cmax is the peak plasma concentration which shows whether the drug is being absorbed systemically so that it can be able to provide a therapeutic response. Tmax is the peak time which will give the indication of the rate of absorption. The area under the plasma level-time curve gives the measure of the quantity of absorption of the drug that reaches the systemic circulation.
Question 10
Which of the following is not an objective of bioavailability studies?
A. Primary stages of development of suitable dosage form for new drug
B. Determination of the influence of excipients, patient-related factors, etc
C. Development of new formulations of the existing drugs
D. Control the quantity of the drug to be administered
View Answer
Answer: Option D
Explanation:
More than the quantity, bioavailability studies are more used to study the quality of a drug product during the early stages of marketing so that the influence of processing factors, storage, and stability on drug absorption can be determined. Other objectives are the development of suitable dosage form, determination of the influence of excipients, patient-related factors, etc. and development of new formulations of the existing drugs.
Question 11
Which of the following is not measured in acute pharmacological response study?
A. ECG
B. EEG
C. Pupil diameter
D. Serum drug level
View Answer
Answer: Option D
Explanation:
When bioavailability measurement using pharmacokinetic processes are difficult, inaccurate, non-reproducible, acute pharmacological effect such as a change in ECG, EEG, pupil diameter, etc. is related to the time course of a given drug. Bioavailability can then be calculated by construction the pharmacologic effect-time curve as well as dose-response graphs.
Question 12
Which of the following will not be a parameter that should be examined for urinary excretion data?
A. (dXu/dt)max
B. (tu)max
C. Xu
D. Cmax
View Answer