Question 1

According to pH partition theory, a weak acidic drug will most likely be absorbed from the stomach because the drug which exist primarily in the

Accepted Answer

Weak acidic drugs are more likely to be absorbed from the stomach because they exist primarily in their unionized, more lipid-soluble form in the acidic environment of the stomach, facilitating their passage through the lipid bilayer of cell membranes.

Question 2

Very weak bases having pKa < 5

Accepted Answer

C

Question 3

IV route of drug administration does not involve…………

Accepted Answer

The intravenous (IV) route of drug administration bypasses the absorption step because the drug is directly introduced into the bloodstream, ensuring immediate effect. Distribution and biotransformation steps are still involved in the process.

Question 4

In carrier mediated transport energy is derived from……..

Accepted Answer

Carrier mediated transport, specifically active transport, derives energy from the hydrolysis of ATP to move substances against their concentration gradient.

Question 5

Which of the following drug is not stable in the gastric fluid?

Accepted Answer

Erythromycin is not stable in gastric fluid due to its acid-labile nature, which leads to its degradation in the acidic environment of the stomach.

Question 6

………types of drugs are absorbed by pore transport mechanism.

Accepted Answer

Pore transport mechanism primarily facilitates the absorption of small, water-soluble drugs with a molecular weight less than 100. This is because the pores or channels in biological membranes are typically only large enough to allow the passage of small molecules.

Question 7

Area in which the carrier system is most dense is called as…………..

Accepted Answer

The term "absorption window" refers to the part of the gastrointestinal tract where a drug's absorption is most efficient, indicating the area where the carrier system is most dense for that drug.

Question 8

Which of the following is carrier mediated transport system

Accepted Answer

Active transport is a carrier-mediated transport system that moves substances across a cell membrane against their concentration gradient, requiring energy in the form of ATP.

Question 9

Absorption of poorly soluble drug is

Accepted Answer

Poorly soluble drugs are typically dissolution rate limited because their rate of dissolution in the gastrointestinal fluids is slower than their rate of diffusion across the intestinal membrane.

Question 10

Which of the following process drug moves from site of administration to systemic circulation?

Accepted Answer

Absorption is the process through which drugs move from the site of administration into the systemic circulation, allowing them to exert their effects on the body.

Question 11

Based on Henderson-Hasselbalch equation, at what pH value a weak acid would be 99.9% ionized?

Accepted Answer

The Henderson-Hasselbalch equation relates the pH of a solution to the pKa (acid dissociation constant) and the ratio of the concentrations of the deprotonated form (A-) to the protonated form (HA) of the acid. For a weak acid to be 99.9% ionized, the ratio of A- to HA must be 1000:1. According to the equation, pH = pKa + log([A-]/[HA]), when [A-]/[HA] = 1000, log(1000) = 3, so pH = pKa + 3.

Question 12

In passive diffusion, the transport of drugs takes place from a region of ……………concentration to a ……………..concentration.

Accepted Answer

Passive diffusion is a process where substances move from an area of higher concentration to an area of lower concentration without the need for energy.

Question 13

Which is the major process of absorption for more than 90% of drugs?

Accepted Answer

Passive diffusion is the major process through which more than 90% of drugs are absorbed. This process relies on the concentration gradient, allowing substances to move from an area of higher concentration to one of lower concentration without the need for energy input.

Question 14

What is the driving force for Passive Diffusion?

Accepted Answer

Passive diffusion is driven by both concentration gradients (difference in solute concentration across a membrane) and electrochemical gradients (difference in charge and chemical concentration across a membrane). These gradients provide the energy for molecules to move from an area of high concentration to an area of low concentration or from an area of high electrochemical potential to an area of low electrochemical potential, without the need for cellular energy (ATP).

Question 15

Which kind of molecules cannot pass through a pore transport?

Accepted Answer

Molecules greater than 400 Dalton are typically too large to pass through most pore transport systems, which are designed to allow the passage of smaller molecules.

Question 16

What is the driving force of Pore Transport?

Accepted Answer

The answer of What is the driving force of Pore...

Question 17

What will be the best definition for "carrier"?

Accepted Answer

Carriers bind reversibly and non-covalently with molecules to transport them across cell membranes, facilitating their movement without being consumed or destroyed in the process.

Question 18

What is the major difference between Facilitated diffusion and Passive diffusion?

Accepted Answer

Facilitated diffusion differs from passive diffusion primarily because it involves carrier proteins or channels to transport substances across the cell membrane, whereas passive diffusion does not require such mediators.

Question 19

What influences the permeation of drugs in an Ionic or Electrochemical diffusion?

Accepted Answer

The answer of What influences the permeation of drugs in...

Question 20

Which kind of drugs are absorbed through endocytosis?

Accepted Answer

Macromolecular drugs or drugs as oily droplets are typically absorbed through endocytosis due to their large size or inability to passively diffuse through the lipid bilayer of cell membranes.

Quiz 3: Drug Absorption Mechanisms and Processes