Pharmaceutical Sciences Flashcards
6 cards from real PSI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pharmaceutical Sciences flashcards as text
Which type of drug interaction at receptor level is reversible and competitive?
Answer: Competitive antagonism
Competitive antagonists bind reversibly to the same receptor site as the agonist. Increasing agonist concentration can overcome the antagonism, shifting the dose-response curve to the right.
The Noyes-Whitney equation describes the rate of:
Answer: Drug dissolution
The Noyes-Whitney equation describes how dissolution rate depends on surface area, diffusion coefficient, solubility, and boundary layer thickness.
Which packaging component directly contacts the dosage form?
Answer: Primary packaging
Primary packaging is in direct contact with the product (e.g., blister foil, ampoule, bottle). It must be compatible with the formulation and protect against degradation.
Emulsions are thermodynamically unstable — which process describes droplet merging?
Answer: Coalescence
Coalescence is the irreversible merging of emulsion droplets into larger droplets, ultimately leading to phase separation. Emulsifiers prevent coalescence by forming interfacial films.
Which analytical technique is the gold standard for structural elucidation of drug molecules?
Answer: Nuclear Magnetic Resonance (NMR) spectroscopy
NMR spectroscopy provides detailed information on the chemical environment of atoms within a molecule, making it the most definitive tool for structural characterisation.
A drug with a narrow therapeutic index requires:
Answer: Therapeutic drug monitoring
Narrow therapeutic index drugs (e.g., digoxin, warfarin, lithium) have small differences between effective and toxic concentrations, necessitating regular plasma level monitoring.