Active transport differs from facilitated transport in following ways, except

Correct Answer: A

Rationale: Carrier involvement (A) is common to both active and facilitated transport, using specific proteins (e.g., glucose transporters). Active transport (e.g., Na⁺/K⁺ pump) moves against the gradient (B) and requires energy (C, ATP), unlike facilitated transport (e.g., GLUT1), which is passive, down the gradient. Option D is incorrect as A is the exception. This carrier-mediated similarity distinguishes both from simple diffusion, but active transport's energy use enables uphill movement, critical for homeostasis and drug uptake (e.g., levodopa), impacting pharmacokinetics.

Correct Answer: A

Rationale: Trituration (A) best describes rubbing or grinding a substance in a mortar with a rough inner surface (1), reducing particle size (e.g., sulfur). Spatulation (B) mixes without grinding. Levigation (C) uses a liquid for a paste (3). Pulverization by intervention (D) adds a solvent (2). Tumbling (original E) is industrial mixing. Trituration's mechanical action ensures fine powders, enhancing dissolution in extemporaneous preparations, a fundamental pharmacy skill.

Correct Answer: B

Rationale: Dose dumping is a problem in modified-release drug products (B), where unintended rapid release (e.g., from matrix failure) causes toxicity (e.g., theophylline). Compressed tablets (A) and capsules (C, D) are immediate-release unless modified. Suppositories (original E) rarely involve controlled release. This failure risks overdose, necessitating robust design (e.g., coating integrity) and testing, critical in chronic therapies to maintain steady plasma levels and avoid adverse effects.

Correct Answer: D

Rationale: Insulin renal clearance measures glomerular filtration rate (GFR) (D), as insulin is freely filtered and minimally reabsorbed/secreted, approximating GFR (e.g., 120 mL/min). Effective renal blood flow (A) uses PAH clearance. Drug excretion rate (B) varies by mechanism. Enzyme activity (C) is hepatic. Active secretion (original E) isn't insulin's path. GFR assessment via insulin, though less common than creatinine, ensures accurate renal function evaluation, vital for dosing renally cleared drugs.

Correct Answer: B

Rationale: R-COOR (B), an ester, is most susceptible to hydrolysis, cleaved by water into an acid and alcohol (e.g., aspirin to salicylic acid), common in drug degradation. R-CO-R (A, ketone) and R-O-R (C, ether) resist hydrolysis. R-NH-CH₃ (D, amine) and R-COOH (original E, acid) are stable. Esters' labile carbonyl-oxygen bond, catalyzed by pH or enzymes, drives this susceptibility, necessitating stable formulations (e.g., dry storage), a critical stability factor in pharmaceuticals.