PHM 652: Exam 1 Flashcards
what are ointments (USP) definition
semisolid preparations intended for external application to the skin or mucous membranes.
also an umbrella term often used loosely to include : pastes, creams, gels, plasters, poultices
basically ALL SEMISOLID TOPICALS
specific definition of ointments
characteristics
an unofficial specific classification for oleaginous topicals (petrolatum, lanolin, or other semisolid oil/greese based preparations
insoluble in water
emolient
occlusive
greasy
incorporation in terms of ointments
the process of combining semi-solid masses
when levigating, how much of the levigating agent should we use?
a minimal amount
Levigating agents for ointments
powder must be insoluble in agent
ideal a LMW version of the base itself or a low viscosity agents compatible with the base
examples of levigating agents for common ung. bases
What is the purpose of these?
mineral oil (for use with petrolatum)
glycerin (for use with PEG)
LMW PEG ( for use with PEG)
to help with levigation to incorporate into the base
ideal a LMW version of the base itself or a low viscosity agents compatible with the base
solubilization agents
agents that aid the incorporation of drugs that are soluble in the ointment base.
should be compatible with the absorption base
powder must be soluble in the solubilization agent and ung. base.
creams
same usp definition for ung.. BUT
separate usp classification used for WATER-REMOVABLE/ SOLUBLE UNG
usually not termed an ung.
gels
semisolid systems consisting of either suspensions made up of small inorganic particles or large organic molecules interpenetrated by a liquid
pastes
similar to usp definitin
general high viscosity
stiff
protective property
generally an ung with >20% w/w powder
what’s the diff btw topical vs transdermal
same location of application.
topical: applies to the tissues where ailment exists
transdermal: intent for active ingredient to be systemically distributed into the blood
emolient
substance that promotes the moisturization of tissues
use of ointment as a term
general
specific
general: ointment= semisolid
specific: oleagenous/ hydrocarbon base class (5 main classes)
ideal ointment
if there was such a thing
spreads easily
compatible with tissues
a. non irritating
b. hypoallergenic
b. non abrasive
b. isotonic
stable ( physical, chemical, microbiologic)
smooth and pliable
softens and melts at body room tmep
easily removed
ready release of medication
doesn’t stain clothing
5 main classes of ointment bases
- hydrocarbon/ oleaginous
- anhydrous absorption
- water in oil emulsion
- oil in water emulsion
- water soluble
ointment base characteristics
hydrocarbon oleaginous bases
water soluble: water washable: anhydrous: absorbs water: emollient: occlusive: greasy:
water soluble: no water washable: no anhydrous: yes absorbs water: no emollient: yes occlusive: yes greasy: yes
ointment base characteristics
anhydrous absorption bases
water soluble: water washable: anhydrous: absorbs water: emollient: occlusive: greasy:
water soluble: no water washable: no anhydrous: yes absorbs water: yes emollient: yes occlusive: yes greasy: yes
ointment base characteristics
water in oil emulsion absorption bases
water soluble: water washable: anhydrous: absorbs water: emollient: occlusive: greasy:
water soluble: no
water washable: no
anhydrous: no (meaning they contain water)
absorbs water: yes (somewhat b/c they are an emulsion and already contain some water)
emollient: yes
occlusive: yes
greasy: yes
ointment base characteristics
oil in water emulsion, water-removable bases
water soluble: water washable: anhydrous: absorbs water: emollient: occlusive: greasy:
water soluble: no
water washable: yes
anhydrous: no (meaning they contain water)
absorbs water: yes (somewhat b/c they are an emulsion and already contain some water)
emollient: no
occlusive: no
greasy: no
ointment base characteristics
water soluble bases
water soluble: water washable: anhydrous: absorbs water: emollient: occlusive: greasy:
water soluble: yes water washable: yes anhydrous: yes absorbs water: yes (somewhat) emollient: no occlusive: no greasy: no
hydrocarbon/ oleaginous bases detailes
when is it useful?
examples:
notes:
when used: useful when high % of powder is to be incorporated into base
(10-25%)
ex: petroleum (petrolatum, vaseline)
a. high viscosity
b. will not become rancid
animal fats/ oils) (lard, sweat ( sheep fat), lanolin derivatives(secretion of sebaceous glands of sheep).
a. may become rancid
vegetable oils (crisco)
a. useful as an additive to lower melting point and soften product
b. may be hydrogenated to promote solidification @ room temp
c. may become rancid
main examples for ung classes
- hydrocarbon /oleaginour
- anhydrous
- water in oil emulsion
- oil in water
- water soluble
- petrolatum
- aquaphor
- eucerin
- hydrophilic ointment
- PEG
anhydrous bases
when are they useful?
examples:
notes:
useful: for incorporation of aqueous liquids and/or water soluble drugs to the emulsions internal phase
examples:
origin: petrolatum( aquaphor, hydrophilic petrolatum), lanolin USP (has allergic tendencies)
notes: can absorption up to 2x their weight in water.
1:1 ratio in lab policy tho.
will also absorb oil based substances also
will not dissolve in water
not emulsions by themselves
water in oil emulsion absorption bases
when are they useful?
examples:
notes:
useful: often used for emollient properties alone but can also be a vehicle for ingredients
ex: anhydrous lanolin cold cream rose water ointment eucerin hydrocream
oil in water emulsion water-removable bases
examples:
notes:
ex: hydrophilic ointment (35-375)
vanishing cream
dermabase
unibase
notes: water washable
dries out easily. feels
water soluble ung bases
examples:
notes:
ex: PEG
notes: wide range of viscosity
doesn’t contain oil or water
what happens when the asource material provided to compound an ung. is an ung.
- calculate the regular amounts needed based on rx
2. calculate amount of source ung. that contains the amount of active ingredient needed
purpose of suppository
altenrate administration route for..
NPO pts
unconscious pts
infant
- non invasive alternative to IV
disadvantages of suppository
- PO vs PR
dignity, comfort, convenience - privacy. cant be administered in public
usp definition of suppositories
what are some indications
solid, unit dosage forms intended for admin of medications into variety of orificies of the body . ie. recum, vagina, or urethra
melt or dissolve in body cavity
indicated for admin. of drugs to infants/ small children, severely debilitated pts.
indications for suppositories
local
systemic
local: hemmorhoids
itching
infections
systemic
analgesics
anti-nausea
antihistamine
types of suppositories (where they can be inserted)
rectal
a. adult: 2 grams
b. children: 1 gram, more pencil shaped
vaginal- pessaries
urethral- bougies
nasal
aural (into ear)
rectal suppositorie purposes
local effect
laxation effect
systemic effects
ex of vaginal suppository purposes
fertility (progesterone 25mg-400 mg)
ideal suppository base charcateristics
stable
non irritating
chemically and physiologically inert
compatible with all drugs
melt or dissolve in rectal fluids
solid below 98.6 F. liquid aloe 98.6
not bind or interfere w. release of drug substances
suppository bases
cocoa butter
what is the prefferebale form. why?
aka theobroma oil
no longer the base of choice when other is specified
4 possible polymorphic forms.
BETA shown suitable for compounding of suppositories b/c melting pt is above room temperature
when over heated, it can slip into other non suitable polymorphic forms
soften at 30 C, melts at 34 C
suppository base properties
fattibase
similar to cocoa butter, but no special storage conditions, doesn’t have overheating problem
suppository base properties
PEG
water soluble
base of choice when none other is specified
suppository base properties
GLYCERIN
WATERSOLUBLE
types of suppository bases
- cocoa butter
- fattibase
- PEG
- glycerin
methods of making suppositories
- hand rolling
- compression (injection mold)
- fusion
- mold reparation
- prepration of base
- preparation of drug
- heating, mixing and pouring
- cooling and finishing
when drug/base used in a suppository is a suspension…. what should you do
levigation/ geometric combo may be necessary
constant stirring during pouring is necessary
pour at relatively cool temps
types of molds for supossitories
metal mold
disposable plastic mold
considerations for using metal molds for suppositories
need to use an ejection agent
important that the ejection agents is not soluble in the base
use a q-tip applicator to coat the inner surface of the metal mold with the ejection agent
proper ejection agents for suppository bases
- Green soap:
a. Cocoa butter
b. Fatibase - Mineral oil
a. glycerin
b. PEG
why should water be avoided in compounding of suppositories
oxidation of fats
increase degredaion
support micro. growth
dissolved drugs may crystallize when water evaporates
viscosity
brittleness
suppository compounding considertions
density of incorporated materials
volume contraction
example incompatibilities
in a suppository, PEG isn’t compatible with
aspirin
benzocaine
rate of drug release times for bases
cocobautter
fatti base
glycerinated gelatin
PEG
- 3-7 min
- 3-7 min
release by meltinggg - 30-40 min
- 30-40 min
release by dissolving
drug absorption rates
drug: oil soluble
base: oily
SLOW
drug absorption rates
drug: WATER SOLUBLE
base: oily
rapid
drug absorption rates
drug: oil soluble
base: water miscible
moderate
drug absorption rates
drug: water soluble
base: water miscible
moderate
how do bases release drugs
OILY-
water soluble bases-
melt (cocoa butter, fattibase)
dissolve (PEG, glycerin)
what is the mold calibration value?
what is this value specific to?
average mass of one pure base suppository cast in the mold
mold specific
base specific
not specific to drug
how to find mold calibration value
- prepare pure base suppositories
- weight total quantity
- divide total mass by # of suppositories.
density factor in suppositories?
what is this value specific to
ratio of unit mass of drug powder to the amount of suppository base displaced by the powder
NOT mold specific
is base specific
is drug specific
ex of how to calculate density factor
if 1 g of drug powder displaces 0.8 g of suppository base, what is the density factor
what are the units of density factor
mass of drug: 1 g
amount of supp. base displaced: 0.8g
X= 1g/0.8g X= 1.25
UNITLESS
how to calculate how much base to remove when given the drug amount and the Density factor (DF)
ex problem: a suppository is to contain 200 mg of drug in a suitable base. DF is 1.25. .
how much base will be displaced by the drug
df= 1.25
1.25/1=200/x
x=200/1.25
x=160 mg of base will be displaced
when talking about density factor, discussed in respect to what..
a drug (powder) in a base
pharmacy lab policy for suppositories
calculate and compound mass for 2 extra suppositories.
refrigerate your mold, don’t freeze
don’t pre refrigerate mold
write down your mold #
DIV notation vs DTD notation
DIV: the dose of drug is to be divided into # specified on rx
DTD: each drug is to contain a dose of the one specified above in the rx
notes for calculations of suppository ingredients
must have mold calibration value.
- CALCULATE HOW MUCH PURE BASE NEEDED: calculate the amount of pure base needed to compound prescription (+2 extra) by multiplying # of suppositories by the mold calibration value.
- FIND THE DISPLACEMENT VALUE: divide the amount of drug needed by the DF of that drug in base to get the displacement.
- ACTUAL MASS OF BASE NEEDED: subtract the displacement from the total mass of base needed originally. this will give actual amount of base needed
compounding procedure notes for making suppositories
need to set up a steam bath
apply a thin later of mold ejection agent to the inner surface of mold
place drug in casserole dish
warm up casserole dish
levigate drug in minimal amount of base. facilitate with a glasswork stirring rod until homogenous and smooth
pour into suppository into mold cavities with continual mixing pour/ fill
allow to fully cool. shave tops with razor blade
remove finished suppositories from mold.
if given a plastic suppository mold on a test, how do you keep them upright?
can use the metal mold to hold the plastic molds upright. loosen the metal molds, place the ends of plastic mold inside, and clamp
how to determine DFwhen given unknown drug and base in lab (df exercise)
- create pure base supp.
- weigh total. divide by # of supp. . this is the mold calibration value
- remelt the suppositories. incorporate drug powder corresponding to 20% of the total support. mass. levigate with base and create new suppositories
- weight out toal mass of recast suppositories
- calculate total compounded mass (mass of pure base supp. + mass of drug powder added)
- calculate how much powder mass would be contained in the recast supposed by setting up a ratio
- calculate mass of supp. base contained in the recast supp. by subtracting powder mass in recast from total recast mass.
- calculate the amount of displaced base by subtracting original pure base mass minus the pure base mass in recasted supp.
- DF= drug amount/ amount of base displaced
density factor conversion
(density of base A)/(density of base B)=
DF of drugs in base b)/ (DF of Drug x in base A
density of..
polybase
fattibase
- 77 g/mL
0. 9 g/mL
