A 22-year-old woman suffering from asthma was prescribed albuterol by inhalation. Albuterol is a bronchodilating drug with a molecular weight of 239 daltons. Which of the following permeation processes most likely accounted for the transfer of the drug through the bronchial mucosa?

Correct Answer: B

Rationale: Lipid diffusion is the most likely permeation process for the transfer of albuterol through the bronchial mucosa. Lipid-soluble molecules like albuterol can easily pass through the lipid bilayer of cell membranes. The other options are less likely mechanisms for the absorption of albuterol in this context.

Correct Answer: C

Rationale: The correct answer is C. Stereoselectivity refers to the phenomenon where one enantiomer of a drug has a significantly higher binding affinity to a receptor compared to its mirror-image enantiomer. In this scenario, one enantiomer binds substantially while the other shows negligible binding, indicating stereoselectivity in receptor binding. This property is crucial in drug development as it can impact the efficacy and safety profile of a medication. Intrinsic activity (choice A) refers to the ability of a drug to activate a receptor once bound, while affinity (choice B) is the strength of binding between a drug and its receptor. Potency (choice D) refers to the dose of a drug required to produce a specific effect, and variability (choice E) is the degree of inconsistency in response to a drug.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Infliximab, as a monoclonal antibody, is a large molecule that is more likely to distribute to tissues like fat due to their ability to store and release drugs slowly. Fat tissue is a common site of distribution for large molecules and lipophilic drugs. Therefore, fat tissue is the most likely main site of distribution for infliximab.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.