MPharm Master of Pharmacy Master of Pharmacy: Pharmaceutical Technology and Drug Delivery Systems 3

Question 1

Which nanoparticle property is measured by the polydispersity index (PDI), and what PDI value indicates a monodisperse distribution?

Accepted Answer

Particle size distribution uniformity; PDI < 0.1

Answer

Zeta potential; PDI < 0.5

Answer

Surface charge; PDI = 1.0

Answer

Drug loading efficiency; PDI > 0.8

Question 2

In mucoadhesive drug delivery systems, which polymer property is most critical for achieving strong mucoadhesion?

Accepted Answer

Presence of hydrogen-bonding functional groups (e.g., hydroxyl, carboxyl)

Answer

High melting point and crystallinity

Answer

Hydrophobicity and low water uptake

Answer

High molecular weight aromatic backbone

Question 3

Which in vitro dissolution test apparatus is most appropriate for evaluating drug release from transdermal patches?

Accepted Answer

USP Apparatus 5 (paddle over disk)

Answer

USP Apparatus 1 (basket)

Answer

USP Apparatus 2 (paddle)

Answer

USP Apparatus 4 (flow-through cell)

Question 4

What is 'hot-melt extrusion' primarily used for in pharmaceutical manufacturing?

Accepted Answer

Creating amorphous solid dispersions to enhance solubility of poorly soluble drugs

Answer

Sterilization of thermolabile drugs by heat

Answer

Coating multiparticulate systems with aqueous polymer dispersions

Answer

Preparing lyophilized injectable products

Question 5

In self-emulsifying drug delivery systems (SEDDS), what happens upon dilution with GI fluids after oral administration?

Accepted Answer

The lipid-surfactant mixture spontaneously forms an oil-in-water emulsion or microemulsion

Answer

The formulation crystallizes and precipitates the drug

Answer

Phase inversion from O/W to W/O occurs immediately

Answer

Enzymatic hydrolysis is completely inhibited

Question 6

Which rheological property of a gel formulation is described by the term 'thixotropy'?

Accepted Answer

Time-dependent reversible decrease in viscosity upon shearing, recovering at rest

Answer

Increase in viscosity with increasing shear rate

Answer

Constant viscosity regardless of shear rate (Newtonian behavior)

Answer

Irreversible structural breakdown under shear stress

Question 7

What is the role of cryoprotectants (e.g., trehalose, mannitol) in lyophilized biological drug products?

Accepted Answer

They prevent ice crystal formation from damaging protein structure during freezing

Answer

They increase the eutectic temperature to speed up the freezing process

Answer

They act as antimicrobial preservatives in the final product

Answer

They increase the vapor pressure of ice to speed up primary drying