Master of Pharmacy: Pharmaceutical Technology and Drug Delivery Systems Flashcards
7 cards from real MPharm Master of Pharmacy practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Master of Pharmacy: Pharmaceutical Technology and Drug Delivery Systems flashcards as text
Which parameter in the Noyes-Whitney equation directly describes the rate of drug dissolution?
Answer: Surface area of the dissolving solid
The Noyes-Whitney equation states that dissolution rate is directly proportional to the surface area of the solid, so smaller particle size (larger surface area) increases dissolution.
In liposomal drug delivery, what is the term for liposomes engineered to avoid rapid clearance by the mononuclear phagocyte system?
Answer: Stealth liposomes
Stealth liposomes are coated with polyethylene glycol (PEG), which creates a hydrophilic shield that prevents opsonization and prolongs circulation time.
Which type of controlled-release mechanism relies on osmotic pressure to drive drug release at a constant rate?
Answer: Elementary osmotic pump (OROS)
The elementary osmotic pump uses a semipermeable membrane and an orifice; water enters by osmosis, creating pressure that pushes drug solution out at a controlled zero-order rate.
What is the primary purpose of using a plasticizer in film-coating of tablets?
Answer: To improve flexibility and reduce brittleness of the coating film
Plasticizers like polyethylene glycol or triethyl citrate are incorporated into polymer coatings to reduce glass transition temperature, making the film more flexible and preventing cracking.
Which emulsification theory explains stabilization of emulsions by the formation of a monomolecular film at the oil-water interface?
Answer: Interfacial film theory
The interfacial film theory states that emulsifying agents form a condensed, coherent monomolecular film at the interface that mechanically prevents coalescence of droplets.
In solid lipid nanoparticles (SLNs), which characteristic distinguishes them from conventional lipid emulsions?
Answer: The lipid core is solid at body temperature
SLNs use lipids that remain solid at physiological temperature (37°C), providing a solid matrix that offers controlled drug release and enhanced physical stability compared to liquid nanoemulsions.
What does a drug's HLB (Hydrophilic-Lipophilic Balance) value of 4 indicate about its primary use?
Answer: Suitable as a water-in-oil (W/O) emulsifier
A low HLB value (3–6) indicates a predominantly lipophilic surfactant, which preferentially stabilizes water-in-oil emulsions where water droplets are dispersed in an oil phase.