Pharmaceutics I Final Exam (2025)

A drug substance is known to degrade by the stomach acid. Which of the following dosage forms is preferred in such a situation?

Enteric coated tablet dosage form

How do you define BCS Class I drugs?

High permeability, high solubility

If ‘ABC’ in the following picture is a pile of powder created on a surface as the powder was freely fallen from a funnel, which one is the angle of repose?

θ₂

Zinc chloride can provide a pair of electrons to form a coordination covalent bond. Therefore, zinc chloride can be called

a base according to Lewis theory

Water and alcohols can be considered __________ solvents?

amphiprotic

Calculate the buffer capacity of a pharmaceutical buffer at pH 6.3. The Ka value is 1.51 × 10–6. The buffer contains 0.2 M conjugate acid and 0.5 M conjugate base. [

0.302

What is the flux in mg/cm²/sec if 0.2 mg of a drug diffuses through a cross-sectional

area of 0.008 cm² in 20 seconds at 25 °C?

1.25 mg/cm2/sec

Noyes-Whitney equation is used to determine this parameter.

Drug dissolution

What type of chemical degradation is apparent from the following reaction?

Hydrolysis

A complex reaction that occurs through a series of chain reactions via a free radical mechanism is called ______________.

auto-oxidation

What is the true function of synergists in pharmaceutical preparations?

To increase the activity of antioxidants.

All of the following EXCEPT this one are chemical methods of drug degradation.

Polymorphism

Which one is NOT true for molecularity and order of a reaction?

Molecularity must be experimentally determined.

A drug formulation initially contained 225 mmol/liter of the drug. It was tested under the accelerated stability testing and found to contain 100 mmol/liter after 45 days.

Calculate the half-life of the degradation process if it follows first order kinetics.

38.5 days

A solid oral dosage form is evaluated for real time stability studies at ___________.

25 °C/60% RH

Which of the following statements correctly explains chemisorption?

It is when adsorption occurs due to the formation of chemical bonds.

What type(s) of ion(s) are adsorbed on the true surface of an adsorbent?

Only potential determining ions

How would you express Newton’s Law of Flow?

Shearing stress is proportional to the rate of shear.

Describe the characteristic of a thixotropic system.

Thixotropy offers easy pouring and spreading of medicines.

Which of the following is the most electronegative atom?

Fluorine

Water is considered to be a ____________ solvent.

polar

Which of the following is true for a solution system with negative heat of solution?

Heat evolves during the dissolution process.

Arecoline is a weakly basic drug with a pKa of 8.23. You have a stock solution of 3.22 moles/liter of arecoline in sterile water for injection. The solubility of arecoline in water is 2.88 moles/liter. What would be the pH of precipitation of arecoline in the stock solution?

9.16

Which of the following statements is consistent with flocculated suspensions?

Particles in sediments are weakly bonded.

The rate of sedimentation of a suspension is 4.31 × 10–4 cm/sec when the particle size is 3.9 μm.

What would be the rate of sedimentation if the particle size is reduced to 1.6 μm?

7.25 × 10–5 cm/sec

What is the contact angle between the liquid and the solid surface in the following picture?

>90°

Which of the following instruments or methods use rollers to crush the disperse phase in preparing lyophobic colloids?

Colloid mills

There are, on average, 30 monomers in each micelle in the association colloid you prepared recently. Therefore, “30” is known as the _________________ of this system.

aggregation number

In which phase of clinical trial post marketing surveillance is conducted?

Phase IV

Which of the following statements regarding drug absorption is correct?

Drug should exist in non-ionized and lipid soluble form.

Which of the following cyclodextrins would you select to prepare intravenous solution of a hydrophobic drug?

Gamma cyclodextrin

Glycerin procured from unverified source is often adulterated with _______________.

diethylene glycol

Doctor recommended antiseptic solution to treat a mild throat infection. Which of the following preparations would you choose to localized drug effect over the throat region?

Gargles

Which of the following statements regarding salt formation technique is NOT correct?

Salt decreases first pass metabolism of a drug.

Which of the following ointment bases have the highest occlusive effect over the dry skin?

Oleaginous bases

A semisolid preparation contains 30% drug suspended in poloxamer gel. Which of the following semisolid preparation it represents?

Paste

Which of the following mechanisms is NOT involved in drug release from suppository preparations?

Evaporation

Which of the following dosage forms avoid first pass metabolism completely?

Pessaries

A nasal solution contains dextrose in its composition. What is the function of dextrose in the nasal solution?

Sweetener

Which of the following mechanisms is present in olfactory region of nasal cavity to prevent drug entry to the brain?

P-glycoprotein efflux

Which of following oral inhalation preparation requires forceful inhalation?

DPI

A patient is undergoing severe/acute asthmatic attack. Which of following oral inhalation preparations is the most effective against it?

Nebulizer

How many phases are present in a pMDI preparation that contain solution formulation? The solution formulation is miscible with liquid phase of the HFA propellant.

Two phases

The volume ratio of oil to water in a given emulsion preparation is 45:55. If the emulsifier used in this preparation is hydrophilic in nature, the type of emulsion that will be formed most likely is ___________.

o/w type

HLB system is used to classify ______________.

surfactants

What is the primary advantage of preparing emulsions using bottle method?

Volatile oils can be used.

Radioactivity occurs mainly due to a change ___________?

in the nucleus

Which of the following nuclear reaction represents a nuclear fission?

[236] 92U → [131] 53I + [102] 39Y + 3n