Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
3 types of "liquids"
|
monophasic- solutions
Multiphasic- suspensions, emulsions, gel, magma Semi solids |
|
|
factors affecting drug penetration in skin
|
Physiochemical- properties of the drug
properties of the base Physiological factors- properties of skin |
|
|
it is easier to modify _____ factors to get the overall effect
|
Physiochemical
adjust the drug and dosage form to get outcome |
|
|
Ointment
|
protectant (emmolient)
lubricant, occlusive layer (block moisture, sun etc) semi solid medicated or non medicated topical application |
|
|
targets of ointments
|
dermatological-skin
transdermal- not skin, could be blood, muscle |
|
|
Creams
|
w/o emulsion- emmolient
ow emulsion- water washable easier to spread + remove |
|
|
Explain why many products are available as both creams and ointments
|
Allergic reactions
want to wash off easy or stay on patient compliance |
|
|
4 types of Ointment bases?
|
Oleaginous (hydrocarbon)
Absorption Water removable Water soluble |
|
|
type of base
only base capable of absorbing some aq. solution, (adjuncts) |
Absorption
hydrophilic petrolatum USP lanolon USP |
|
|
type of base
oily- hard to wash off --> high residence emollient, occlusive effect |
Oleaginous (hydrocarbon)
petrolatum USP white petrolatum |
|
|
type of base
o/w emulsions |
Water removable
hydrophilic |
|
|
type of base
no oleaginous content, completely water miscible more suited to incorp. of solid substances |
Water soluble
PEG ointment |
|
|
Base selection
factors? |
Release rate (hydrophobic/hydrophilic)
topical or percutaneous absorption occlusion of moisture stability of drug w/ base washable or not surface characteristics |
|
|
Partition theory
|
K=Co/Cw
K=partition coefficient How well drugs release like or different base |
|
|
What are the 2 methods of Ointment preparation?
|
Incorporation
Fusion |
|
|
Incorporation
|
reduce viscosity w/ energy/heat to make homogeneous
mortar and pestle, tile and spatula applicable to solid and liquid meds. |
|
|
How are solids incorporated
|
insoluble- reduce particle size (less gritty)
can be dissolved in solvent b4 incorporation into base. |
|
|
Levigation
|
Reduction of particle size with the aid of a liquid in which the substance is insoluble (wet grinding)
|
|
|
How liquids are incorporated
|
must consider bases capacity to accept the volume needed.
heat can be used as long as AI isnt temp sensitive. |
|
|
Fusion
|
Melting, mixing, cooling, congealing
|
|
|
order of mixing for fusion, depends on ______
|
Melting points
add higher first and others while cooling. heat sensitive and volatile substances added at end |
|
|
Emulsion bases
Heat both oleaginous and aq phase SEPARATELY and then add ___ to ___ phase |
add aq. to oily phase
(adding liquid to semi solid is easier to mix) |
|
|
Compendial requirements
|
microbial content
minimum fill package, storage, labeling (cool, dry, no heat, prevent leak, oxidation, UV |
|
|
It is easier to use a ____ mouth jar or tube
|
wide
less air getting trapped in package |
|
|
additional compendial requirements for opthalmic ointments
|
sterility
metal particle content (from equipment) |
|
|
This type of semisolid is prepared by fusion or incorp.
no levigating agent sticks to its place after application used to absorb secretions cant be used on hairy parts |
Pastes
high ratio of powder (25%) Zn oxide paste 25% Zno w/ white petrolatum |
|
|
solid or semisolids
adhesive masses |
Plasters
|
|
|
Uses of semisolid preparations
|
Dermatological
Nasal- decongest, systemic Rectal-antiinflammatory, analgesic, antipuritic Vaginal- ant infective, contraceptiv Opthalmic (eye)- through cornea |
|
|
_____ compounds are more capable of penetrating through the eye cornea.
Common base? |
lipophilic
White petrolatum + mineral oil STERILITY |
|
|
reasons for limitation of absorption in the eye
|
limited surface area
resistant for permeation continuous washing- tears |
