Semisolid Lecture

Question 1

Define semisolid

Answer 1

Retain their shape until force is applied
Easily deformed
Touch of finger creates a track that does not refill after removal

Question 2

Semisolid systems?

Answer 2

Ointments
Solidified emulsions
Creams
Gels
Magmas
Rigid foam
Pastes
Plasters

Question 3

Application sites?

Answer 3

Skin, eye, nose, vagina, rectum

- local effects

Question 4

Define topical product

Answer 4

Deliver a drug to the skin and treat dermal disorders

Question 5

Define transdermal product

Answer 5

Deliver drug via the skin to the general circulation

Question 6

Define ointment

Answer 6

Hydrocarbon based
applied to skin
Medicated or non-medicated (protective and ;lube)

Question 7

Ointment bases?

Answer 7

Oleaginous (oil based)
Absorption (water inside)
Water-removal (wash with water)
Water-soluble

Question 8

Define oleaginous bases

Answer 8

Protects against moisture escape
Remain longer on skin
Difficult to wsh

Question 9

Categories of oleginous bases

Answer 9

Petrolatum (semisolid, yellow petrolatum)
White petrolatum (decolorized)
Yellow ointment (mixture of petrolatum and yellow wax)
White ointment (mix of petrolatum and white wax)

Question 10

Define absorption bases

Answer 10

Absorbs water or aqueous solution without significant change in consistency

Question 11

Types of absorption bases?

Answer 11

Emulsifiable bases: no water w/o with water (hydrophilic petrolatum)
Emulsion bases: w/o, allow incorporation of water (lanolin)

Question 12

Define o/w emulsions

Answer 12

Removed from skin
Wash with water
PEG

Question 13

Define incorporation with powder

Answer 13

Levigated (grinding an insoluble substance to a fine powder while wet)

Question 14

Define incorporation with liquids

Answer 14

Water soluble mixed with water soluble bases up to a certain limit
- Add aqueous solution with a small amount of hydrophilic base and then mix with oleaginous base

Question 15

Define fusion

Answer 15

All or some of the components are melted together and cooled with constant stirring
- Not melted are added to the congealing mixture as it cools upon stirring

Question 16

Define emulsion base ointments

Answer 16

Oil-soluble ingredients are melted together
Water soluble ingredients are then mixed separrately
Aqueous phase is then added to oil slowly

Question 17

Define reams

Answer 17

One or more med may be dispersed

- Looks creamy because it reflex light

Question 18

Define vanishing cream

Answer 18

o/w emulsion with water, stearic acid and other oleginous components

Question 19

Define pastes

Answer 19

Semisolid
- Larger amount of solid
Stiffer than ointment
- allows paste to remain in place after application

Question 20

Define plasters

Answer 20

Solid or semisolid adhesive masses spread on a backing paper

Question 21

Filling jars?

Answer 21

Filled by transferring weighed amount of the ointment into the jar with a spatula

Question 22

Filling tubes?

Answer 22

Open back end of the tube, opposite the cap end

Question 23

Define jelly

Answer 23

Coherent matrix is rich in liquid

Question 24

Define xerogel

Answer 24

Liquid is removed and only framework remains

Question 25

Gels can be?

Answer 25

Two phase or single phase

Inorganic or organic

Question 26

Define two phase gels

Answer 26

“Magma”

- Consist of floccules of small and distinct particles

Question 27

Define single phase gells

Answer 27

Consist of macromolecules existing as twisted or matted strands
No definite boundary
Strong vander Waals forces

Question 28

Define inorganic gels

Answer 28

two phase

aluminum hydroxide

Question 29

Define organic gels

Answer 29

Single phase

Condensed matrix is dissolved in liquid

Question 30

Define hydrogel

Answer 30

water based

Gelatin

Question 31

Define organogel

Answer 31

Organic liquid base

Petrolatum

Question 32

Properties of gels

Answer 32

Syneresis (gels shrinks bc some liquid squeezes out)
Swelling (gel takes up liquid)
Imbibition (certain amount of liquid but no measurable increase in volume)

Question 33

Define precipitation of dispersed phase

Answer 33

• Prepared by freshly precipitating the disperse phase

- Precipitation reduces the particle size

Question 34

Define gelling agents

Answer 34

Forms gels upon contact with suitable solvent
Powdered gelling agents are mixed with the solution of the drug
- Heating and overnight hydration may be required

Question 35

Bentonite magma?

Answer 35

Used as suspending agent

Question 36

Aluminum hydroxide?

Answer 36

Antacid

- aqueous suspension of gelatinous precipitate insoluble aluminum oxide

Question 37

Milk of magnesia?

Answer 37

Antacid

- Made by precipitates