3.11 Flashcards
_____ semisolid system in which a liquid phase is constrained within an interlocked, polymeric matrix of a natural or synthetic gum.
Gel
drug will be dissolved or suspended in the liquid phase
Gelling polymers include…
tragacanth, sodium alginate, cellulose derivatives, carbomers
Gels can be very good in drug release of their ______, which is left after solvent evaporates and used for drug to diffuse through
porous matrix
Gels also have _____ that can enhance penetration.
Solvents
Topical solutions employ aqueous vehicle and examples include…
Burrow’s solution (aluminum acetate) and Dakin’s Solution (diluted sodium hypochlorite solution)
_____ employ an alcoholic or hydroalcoholic vehicle e.g. iodine ____ (NaI and I2)
Tinctures
Collodions are liquid preparations composed of _____ (cotton derivative) dissolved in a solvent mixture usually composed of alcohol and ether or acetone. with or without added drug.
pyroxylin
Collodion film can seal small wounds and protect surrounding tissue because when applied the solvent evaporates, leaving an ____ filmy residue of pyroxylin.
occlusive
Example of Collodion is ___ a wart remover.
Duofilm
_____ are blends of drug and propellant in a pressurized container. Function as drug delivery systems for solution, suspensions, powders, and emulsions.
Aerosols
____ are useful when the extent of blistering, inflammation, and tenderness makes the application of other dosage forms uncomfortable.
Aerosols (can be sprayed without rubbing= convenience)
______ are solid or semisolid adhesive masses spread upon a suitable backing material and intended for prolonged external application to part to the body.
Plasters
____ aqueous solutions applied in the form of dressing (include gauze and linens soaked in an appropriate solution)
Wet dressings
Solutions of wet dressings are usually either ___ or ____ agents
astringent (stop hemorrhages or secretions by precipitating proteins); antiseptic
Wet dressings (help heal the wounds) cleanse the skin of exudates, crusts and debris, and help maintain drainage of infected areas. Exudate is..
any fluid that has exuded out of a tissue or its capillaries because of injury or inflammation
Repeated applications of wet dressings will promote ___ of the skin.
Drying
____ dispersions of gas in a liquid or solid administered as an aerosol. Application is relatively gentle, tend to break down rapidly without leaving greasy residue.
Foam
Antioxidants may be needed to prevent ____ where there are unsaturated hydrocarbons,
rancidity
BHT, BHA, tocopherol
When ___ is present, preservatives will be necessary to prevent microbial growth.
water
____ substances are present to increase stiffness and/or reduce the tackiness of sticky ointments and creams.
Waxy
e.g. cetyl esters wax, stearic acid, cetyl alcohol
Moisturizers includes occlusive and Humectants. Occlusives inhibit ___ by forming a hydrophobic layer on the surface of the skin
TEWL
transepidermal water loss
____ used in “oil-free” moisturizers but much less able to reduce TEWL than petrolatum. It is a non-oleaginous moisturizer.
Silicone
___- hygroscopic substances that help hydrate the skin and used to improve moisturizing capacity.
Humectant
Humectants help skin retain water work within the skin and on surface of the skin. Works along with ____
NMF
