Lecture 8

Question 1

Solution

Answer 1

A homogeneous mixture composed of one or more substances, known as solutes, dissolved in another substance, known as a solvent. It will not separate over any period of time.

Question 2

Suspension

Answer 2

A heterogeneous liquid preparation containing fine particles of solute uniformly distributed throughout a vehicle.

Question 3

Emulsion

Answer 3

A dispersed system containing at least two immiscible liquid phases.

Question 4

Liquid Dosage Forms - Advantages

Answer 4

• High degree of flexibility possible when fine dosage adjustments are needed.
• Convenient for pediatric and geriatric patients who have trouble swallowing solids.
• Can be easily colored or flavored to make them aesthetically appealing.

Question 5

Liquid Dosage Forms - Disadvantages

Answer 5

• Hard to mask drug taste.
• Cumbersome to transport and measure dose accurately.
• Shelf life of many drugs shortened in aqueous medium.
• Complex manufacturing.
• Difficult packaging, shipping and handling.

Question 6

In an ideal suspension:

Answer 6

1) Suspended particles should remain segregated.

2) Suspension should have appropriate flow properties.

Question 7

Surfactants

Answer 7

• A surfactant (also known as an emulsifier or emulgent) is a substance which stabilizes an emulsion.
• Should be effective at low concentrations, should increase viscosity, and should prevent aggregation of dispersed globules.
• They are therefore soluble in both organic solvents and water.

Question 8

Surfactant Micelles

Answer 8

• The lipophilic ends of the surfactant molecules dissolve in the oil, while the hydrophilic charged ends remain outside, shielding the rest of the hydrophobic micelle.

Question 9

Solid Oral Dosage Forms

Answer 9

• Most popular and widely used dosage forms.
• Represent over 90% of prescription and OTC drugs.
• The three most common oral solid dosage forms are:
– Soft Elastic Capsules, (also called Soft Gel Capsules or Soft Gelatin Capsules)
– Hard Gelatin Capsules
– Compressed Tablets (coated and uncoated)

Question 10

Choice of dosage form depends on…

Answer 10

the solubility of the active pharmaceutical ingredient (API),
– More water soluble forms are formulated as tablets or hard capsules.
– API with limited water solubility is dissolved in non-aqueous vehicles and formulated into Soft Gel Caps.