Bachelor of Pharmacy (B.Pharm.) Pharmaceutics Flashcards

Which excipient is used as a cryoprotectant in lyophilized protein formulations to prevent aggregation during freezing?

Answer: Sucrose

Sucrose and trehalose stabilize proteins during freeze-drying by replacing hydrogen bonds lost when water is removed.

The HLB (Hydrophilic-Lipophilic Balance) value range of 8–18 is preferred for surfactants used as:

Answer: O/W emulsifiers

High HLB values (8–18) indicate predominantly hydrophilic character, favoring formation of O/W emulsions.

Transdermal drug delivery systems are most suitable for drugs with molecular weight less than:

Answer: 500 Da

Skin permeation is generally limited to molecules below ~500 Da; larger molecules cannot efficiently cross the stratum corneum.

Zero-order drug release from a dosage form means the drug is released at:

Answer: A constant rate independent of drug concentration

Zero-order release delivers a constant amount of drug per unit time, providing stable plasma concentrations.

A pharmaceutical suspension that settles slowly and can be easily redispersed with gentle shaking is called a:

Answer: Flocculated suspension

Flocculated suspensions form loose aggregates (flocs) that sediment as a fluffy cake and redisperse easily.

Which polymorphic form of a drug generally exhibits the highest aqueous solubility?

Answer: Amorphous form

The amorphous form lacks long-range crystalline order, resulting in higher free energy and therefore greater solubility than crystalline forms.

Osmotic pump tablets (OROS) control drug release by using:

Answer: Osmotic pressure to pump drug solution through a laser-drilled orifice

In OROS tablets, water influx through a semipermeable membrane generates osmotic pressure that pushes drug out through a drilled hole at a constant rate.