Disperse System

Question 1

Preparations made up of finely divided solids (suspensoids) distributed uniformly in a liquid vehicle

Answer 1

Suspensions

Question 2

Size of Suspensoids

Answer 2

> 0.5mcm

Question 3

Reasons for Formulation of Suspension

Answer 3

Suitable for insoluble solute
Suitable for unstable solute
Mask unpeasant tasting drugs

Question 4

Properties of Good Suspension

Answer 4

a. Particle size of the suspension should remain fairly constant throughout long periods of undisturbed standing
b. Dispersed particles of the suspension should settle slowly & should be readily redispersed upon gentle shaking of the container
c. The suspension should pour readily & evenly from its container

Question 5

Types of Suspensions

Answer 5

Gels
Lotions
Emulsions

Question 6

Semi solid system consisting of suspensions made up of either small inorganic particles or larg organic particles

Answer 6

Gels/Jellies

Question 7

Types of Gels

Answer 7

Single Phase
Two Phase (Magma/Milk)

Question 8

Gels in which macromolecules are uniformly distributed throughout a liquid with no apparent boundaries between the dispersed macromolecules and liquid

Answer 8

Single Phase

Question 9

Single phase Gels are more frequently used in pharmaceutical because

Answer 9

Semisolid State
High degree of clarity
Ease of application and removal

Question 10

Gel mass consisting of floccules of small distinct particles

Answer 10

Twi Phase / Magma / Milk

Question 11

Examples of Two Phase Gels

Answer 11

Bentonite Magma - Suspending Agent
Milk of Magnesia - Antacid

Question 12

A reversible sol-gel/gel-sol formation w/ no charge in volume or temperature,

Answer 12

Thixotropy

Question 13

Gel takes up the liquid but there is no increase in volume

Answer 13

Imbibition

Question 14

Gel takes up the liquid but there is increase in volume

Answer 14

Swelling

Question 15

Gel shrinking

Answer 15

Syneresis

Question 16

Liquid is removed and only frameworks remain.

Answer 16

Xerogel

Question 17

Suspension of solids in an aqeuous medium containing one or more active ingredient

For external use

Answer 17

Lotion

Question 18

Methods of Preparation of Lotions

Answer 18

Trituration
Calamine Lotion, USP (ZnO + Fe2SO3)

Chemical Reactions
White Lotion (ZnSO4 + Sulfurated Potash)

Question 19

Dispersed systems in which the dispersed phase is composed of small globules of a liquid distributed throughout a vehicle in which it is immiscible.

Answer 19

Emulsion

Question 20

Components of Emulsions

Answer 20

Dispersed Phase: Internal Phase / Discontinuous Phase
Dispersion Medium: External Phase / Continuous Phase
Emulsifying Agent

Question 21

Purposes of Emulsions

Answer 21

Increased drug solubility
Increased drug stability
Prolonged drug action
Improved taste
Improved appearance

Question 22

Types of Emulsion

Answer 22

• Oil in water (o/w)
• Water in oil (w/o)
• Multiple Emulsion – w/o/w or o/w/o
• Microemulsion – transparent; most stable

Question 23

Oil is dispersed as droplets in an aqueous medium & external washable products

Answer 23

Oil-in-Water (O/W) Emulsion

Question 24

Used for external preparations when emollient, lubricating, or protective properties are desired

Answer 24

Water-in-Oil (W/O)

Question 25

**Transparent** & have droplet diameter in the nanometer size range; Thermodynamically **stable**

Answer 25

Microemulsion

Question 26

Factors that determine Emulsion Type

Answer 26

**(1) Emulsifier** - Some emulsifiers form either w/o or w/o emulsion, others form only one type **(2) Phase Ratio** (relative amounts of oil & water) - Phase present in greater concentration tens to be the external phase. **(3) Order of Mixing** - The phase that is being added by portions tends to be internal phase

Question 27

Oil in Water in Tests

Answer 27

Dilution Test: Miscible in Water Conductivity Test: Yes Fluorescence Test:No (Dotted Pattern) CoCl2/FIlter Paper: Blue to Pink Dye Staining Test: Amaranth

Question 28

Water-in-Oil Tests

Answer 28

Dilution Test: Miscible in Oil Conductivity Test: No Fluorescence Test: Yes CoCl2/FIlter Paper: No color change Dye Staining Test: Sudan, Scarlet Red

Question 29

Emulsion Methods of Preparation

Answer 29

Dry Gum Method Wet Gum Method Bottle Method In Situ Method

Question 30

Continental Method

Answer 30

Dry Gum Method

Question 31

English Method

Answer 31

Wet Gum Method

Question 32

Forbes Bottle Method

Answer 32

Bottle Method

Question 33

Nascent Soap Method

Answer 33

In Situ Method

Question 34

Component of Dry Gum Method

Answer 34

Oil: Water: Gum (4:2:1)

Question 35

Preparation of Dry Gum Method

Answer 35

(Oil + Gum) + Water

Question 35

Preparation of Dry Gum Method

Answer 35

(Oil + Gum) + Water - added all at once Mortar & Pestle

Question 36

Components of Wet Gum Method

Answer 36

Oil: Water: Gum (4:2:1)

Question 37

Preparation of Wet Gum Method

Answer 37

(Water + Gum) + Oil - Added slowly Mortar & pestle

Question 38

Extemporaneous preparation of emulsion from volatile oils or oleaginous substance of low viscosities

Answer 38

Bottle Method

Question 39

Components of Bottle Method

Answer 39

Oil:Water:Gum (3:2:1 or (2:1:1)

Question 40

TF: Bottle Method is suitable for high viscous substances

Answer 40

False Bottle Method is *not* suitable for high viscous substances

Question 41

Used to form an o/w or w/o emulsion and is for external use only

Answer 41

In Situ Method

Question 42

Soap formed in In Situ Method

Answer 42

Soft Soap Calcium Soaps (Oleic Acid + Lime Water)

Question 43

Reduce the interfacial tension by forming a film at interface

Answer 43

Emulsifying Agent