Ceutics Test 2 Sem 2 Ointments

Front 1

what can semisolid bases be classified as

Back 1

gels (organogels, hydrogels) and emulsion type semisolids

Front 2

what are common semisolid dosage forms

Back 2

gels, ointments, creams

Front 3

what are the clinical uses of ointments, gels, creams

Back 3

anti inflammatory, anti itch, antibiotics, emollients, lubricants, cleansing agents, protective barriers (liquid bandages)

Front 4

what is an ointment

Back 4

semisolid preparations intended for external application to the skin or mucus membranes in which the drug is incorporated into a specific base type

Front 5

what are unmedicated ointments used for

Back 5

lubicants, emollients, protectants

Front 6

what are the classification groups for ointment bases

Back 6

oleaginous
absorption
water-removable
water-soluble

Front 7

what are oleaginous bases

Back 7

emollient effect
occlusive dressing
difficult to wash off (water imiscible)
protects the escape of moisture
aqueous material can be added but in a small amount nad it is difficult to do

Front 8

what are some examples of oleaginous bases

Back 8

petrolatum
white petrolatum
yellow and white ointment

Front 9

what are absorption bases

Back 9

can be used as emollient

not as occlusive as oleaginous base.
not easily removed by water washing.
can be used to incorporate small volumes of aqueous solutions into hydrocarbons (oleaginous bases)

Front 10

what are water removable bases

Back 10

water washable bases
oil in water emulsions resembling creams.
external phase of emulsion is aqeous thus it is easily washed from skin.
can be diluted with aqueous solutions.
capable of absorbing serous discharges.

Front 11

what are water soluble bases

Back 11

do not contain oleaginous components. completely water washable (greaseless). tend to soften greatly with addition of water, so they are not used to incorporate aqueous solutions.

Front 12

what are water soluble bases used for

Back 12

incorporation of solid substances

Front 13

what kind of materials use the fusion method

Back 13

high molecular weight (beeswax and stearyl alchohol)

Front 14

what does stirring and gradual cooling do to substances under the fusion method

Back 14

they form biphasic system

Front 15

what are the benefits of Oil in Water bases

Back 15

easily removed from skin
water washable
don't stain clothes

Front 16

what are the disadvantages of Oil in water bases

Back 16

h2o evaporation
possible bacterial/mold growth

Front 17

what are the methods for preparation of ointment

Back 17

incorporation via mechanical energy (compounds are mixed in with base until uniform)

fusion via heat energy (non heat-labile substances are melted together cooled down with constant stirring till congealed

Front 18

what are the two ways of solid incorporation ointments

Back 18

mechanically diminize large particles and mixing particles until uniform

levigate the large particles by using solvent capable of dissolving the particles

Front 19

what are the methods of liquid incorporation of ointments

Back 19

use solvent capable of fully dissolving the solids

*solvent won't interfer with ointment base or drug stability

Front 20

how are ointments, creams, gels preserved

Back 20

sterility not required unless opthalmic ointment

h20 containing preparations support bacterial growth more than h20 free preparations

Front 21

what are the preservatives

Back 21

paraben
phenols
benzoic acid
quartenary ammonium salts
sorbic acid
methylparaben
propylparaben

Front 22

what are properties of opthalmic ointments

Back 22

must be sterile
contain no preservative (may lead to blindness/irritate eye)

they are sterilized in bulk but dispenced via asceptically

typically suspensions

Front 23

how are ointments packaged

Back 23

jars (glass/plastic/amber/opaque)

tubes(plastic or metal)
metal (aluminum/tin) - inside is coated w/ chemically inert substance

tubes has less chance of contamination

Front 24

what base is greaseless?

Back 24

water soluble bases

Front 25

which type of semisolid is identicle to emulsions

Back 25

creams

Front 26

what are creams

Back 26

semisolid preparations containing one or more medicinal agents dissolved or dispersed in an oil in water or water in oil emulsion or in another water washable base

Front 27

what ointment base is very similar to creams

Back 27

water washable bases (water removable bases)

Front 28

how do vanishing creams work

Back 28

after application water evaporates leaving residue of stearic acid or oleaginous components

Front 29

which one is preferred cream or ointment

Back 29

cream because it is less messy and easier to keep in place

Front 30

how are creams prepared

Back 30

continental/dry gum method
english/wed gum method

Front 31

how many phases do creams have

Back 31

2

Front 32

what are some similarities of creams and emulsions

Back 32

creams and emulsions are practically prepared the same

creams are thicker and don't flow when pouring

Front 33

what is the dry gum method

Back 33

4:2:1

mix 4 parts oil with 1 part gum
grind until uniform
mix in 2 parts aqueous phase
grind until uniform

Front 34

what is the wet gum method

Back 34

4:2:1

mix 2 parts water with 1 part gum
grind until uniform
mix 4 parts oil
grind until uniform

Front 35

what are similarities with the wet gum and dry gum method

Back 35

both creams produced will contain
mechanical energy
and the process can be mechanized

Front 36

what is the principle of mixing creams

Back 36

if additional ingredients are needed such as an excipient before you add them to the cream they must be dissolved in a oil or water depending on their solubility before they are mixed into the cream preparation (this is done to prevent instability of the phases)

ocassionally ingredients are only soluble in the presence of surfactants and as a result are dissolved in the surfactants

Front 37

what are the factors effecting cream stability

Back 37

aggregation of particles (creaming)
seperation (partially or fully) of phases (breaking)
microbial growth
particle size and their distribution
viscosity of external phase
density difference of two phases

Front 38

how can you increase the stability of creams

Back 38

decrease particle size and make them more uniform
increase viscosity of external phase
decrease density difference between phases
incorporate antimicrobial agents (parebans)

Front 39

what must creams be protected against

Back 39

heat (effects stability of 2 phases)
extreme cold
humidity

Front 40

which of the semisolids are a bi-phasic system

Back 40

creams

Front 41

what is a Gel

Back 41

a semisolid preparation of atleast 2 components consisting of a condensed mass enclosing (matrix) and interpernetrated by a liquid

gels can be 1 phase or 2 phase systems

Front 42

what is an example of a gel

Back 42

jelly

Front 43

what is a xerogel

Back 43

a gel w/ the matrix framework only no liquid

Front 44

what are some examples of xerogels

Back 44

acacia tears, gelatin sheets, tragacanth ribbons

Front 45

what is a 1 Phase System

Back 45

similar to hydrogel
gel consisting of macromolecules (polymers) existing as twisted matted strands

Front 46

what are 1 Phase systems held by

Back 46

the units are bound by stronger van der Waals so as to form crystaline/amorphous regions throughout the entire system

Front 47

how do 1 Phase Systems (gels) differ from emulsions

Back 47

1 Phase Systems don't have definite boundaries between the dispersed macromolecules and the liquid

emulsions have defined boundaries/separation

Front 48

what is a 2 phase system

Back 48

gel consists of floccules of small particles rather than large molecules

gel structure is not always stable

such gels may be THIXOTROPIC forming semisolids on standing and becoming liquids upon agitation

Front 49

what is thixotropic

Back 49

this is when gels are semisolids when standing but become liquids upon agitation

Front 50

what are lyophillic gels

Back 50

gels of large organic molecules capable of being solvated or associated w. the molecule of the dispersing phase

Front 51

what are lyophobic gels

Back 51

gels of inorganic particles that are added to the dispersing phase typically water

these gels form two phases w/ little interactions

Front 52

what are organogels

Back 52

gels containing organic liquid NOT H2O

many are oily but some are water washable

Front 53

what is an example of an organogel

Back 53

sorbitan monostearate organogel

Front 54

what are hydrogels

Back 54

gels containing organic or inorganic ingredients that are water soluble or colloidally dispersable

hydrogels retain significant amount of water

some are water soluble but some aren't therefore they are good for topical drug design

Front 55

what is an example of a hydrogel

Back 55

PEG diacrylate

Front 56

what are the colloidal gels

Back 56

lyophillic or lyophobic gels

Front 57

what is solvation

Back 57

attachment of solvent (doesnt need to be water) molecules to molecules of dispersed phase

Front 58

what is hydration

Back 58

hydropillic colloids interacts with water the dispersing medium

Front 59

what does the diffusion rate of hydrogels depend on

Back 59

the physical structure of the polymer network and the chemical nature

Front 60

where does diffusion occurs in HIGHLY HYDRATED GELS

Back 60

through the pores

Front 61

where does diffusion occur in LOWER HYDRATION GELS

Back 61

drug dissolves in the polymer and transported through polymer chains

Front 62

what does cross linking do

Back 62

increases hydrophobicity of gel

decreases the diffusion rate of the drug through hydrogel b/c have more pores that the drug must pass through

Front 63

what is shrinking

Back 63

syneresis

Front 64

what happens during syneresis

Back 64

shrinking, this occurs when a gel is left standing and some of its liquid gets pressed out

this occurs naturally

observed in food gels

THIS FAVORS DRUG RELEASE

Front 65

what happens during swelling

Back 65

enlarging of the gel due ot it taking up liquiod and therefore increasing volume

Front 66

what liquids can bring about swelling

Back 66

only liquids that solvate a gel can bring about swellinh

Front 67

what is imbibition

Back 67

when a gel takes up a certain amount of volume of liquid w/o a measurable increase in volume

Front 68

what does shaking a gel do

Back 68

restores uniformity

Front 69

what must occur in order for gels to maintain good stability

Back 69

as long as hydration is favored thermodynamically

Front 70

what kind of emulsion are absorption bases

Back 70

water in oil