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 parameter best describes the rate of drug elimination from the body?
Answer: Half-life (t½)
Half-life is the time taken for plasma drug concentration to fall by 50%. It directly reflects the rate of elimination and determines dosing intervals.
Michaelis-Menten kinetics apply when enzyme-mediated metabolism is:
Answer: Saturated at high drug concentrations
At high concentrations, metabolic enzymes become saturated and elimination shifts from first-order to zero-order kinetics — described by Michaelis-Menten equations.
Which solid dosage form release mechanism uses an osmotic pump?
Answer: OROS (Osmotic Release Oral System)
OROS uses osmotic pressure to drive water into a core compartment, pushing drug through a laser-drilled orifice at a controlled, constant rate.
Which property does the partition coefficient (log P) measure?
Answer: Lipophilicity of a drug
Log P is the ratio of drug concentration in octanol vs water, indicating how lipophilic a molecule is. High log P means good membrane permeability but poor aqueous solubility.
Hygroscopic drug substances require which type of packaging?
Answer: Moisture-barrier packaging
Hygroscopic substances absorb moisture from the environment, leading to degradation. Moisture-barrier packaging (e.g., blister with aluminium foil) protects product stability.
What does the term 'polymorphism' refer to in pharmaceutical sciences?
Answer: Different crystal structures of the same compound
Polymorphism describes the ability of a solid material to exist in more than one crystal form. Different polymorphs can have different solubility and bioavailability.