SEMISOLID Dosage Forms and Transdermal Systems Flashcards
- semisolid preparations intended for external application to the skin or mucous membranes
- may be medicated or not
- __________ are used for the physical effects they provide as protectants, emollients, or lubricants
Ointments
- unmedicated ointments
Semisolid dosage forms intended for topical applications are:
Ointments
Creams
Gels
Topical applications can be designed for either _________ or _________
local effects or systemic absorption
A ______________ is designed to deliver drug into the skin in treating dermal disorders, with the skin as the target organ.
topical dermatological product
A ___________ is designed to deliver drugs through the skin (percutaneous absorption) to the general circulation for systemic effects, with the skin not being the target organ
transdermal product
May be used for their physical effects or as vehicles for medicated ointments
Ointment bases
USP generally classified ointment bases into four groups. What are these groups?
a) oleaginous bases
b) absorption bases
c) water-removable bases
d) water-soluble bases
- also termed as hydrocarbon bases
- have an emollient effect, protect against the escape of moisture
- effective as occlusive dressing
- can remain on the skin for long periods without drying out
- because of their immiscibility with water, they are difficult to wash
Oleaginous bases
- ________ may be used as the levigating agent when powdered substances are to be incorporated into hydrocarbon bases
- __________ is a purified mixture of semisolid hydrocarbons obtained from petroleum
- an unctuous mass; varying in color from yellowish to light amber
- melts at 38°C to 60°Cn may be used alone or in combination with other agents as an ointment base
- also known as yellow petrolatum and petroleum jelly (ex: Vaseline)
- Liquid Petrolatum (mineral oil)
- Petrolatum, USP
- is a purified mixture of semisolid hydrocarbons from petroleum that has been wholly or nearly decolorized
- used for the same purpose as petrolatum
- due to its lighter color, it is considered more esthetically pleasing
- aka white petroleum jelly (ex. White Vaseline)
- White Petrolatum, USP
- ______ this ointment has the formula of 50g Yellow wax and 950g Petrolatum for the preparation of 1,000 g
- _____ is the purified wax obtained from the honeycomb of the bee Apis mellifera
- aka simple ointment and has a slightly greater viscosity than plain petrolatum
- ______ this ointment differs from yellow ointment by substitution of white wax (bleached and purified yellow wax) and white petrolatum in the formula
- Yellow Ointment, USP
- Yellow wax
- White Ointment, USP
- These bases may be used as emollients, although they do not provide the degree of occlusion afforded by the oleaginous bases
- not easily removed from the skin with water washing due to the external phase of the emulsion is oleaginous
- useful as pharmaceutical adjuncts to incorporate small volumes of aqueous solutions into hydrocarbon bases
- two types of these bases are:
a) those that PERMIT the incorporation of the aqueous solutions resulting in formation of water-in-oil (W/O) emulsions
b) those that are W/O emulsions that permit the incorporation of additional quantities of aqueous solutions
Absorption Bases
- _______ has the a formula of 30g Cholesterol, 30g Stearyl alcohol, 80g white wax, and 860g white petrolatum for the preparation of 1,000g
- Commercial products, ______ and _______, variations of this petrolatum, have the capacity to absorb up to THREE TIMES their weight in water and are useful to help incorporate a WATER-SOLUBLE DRUG into an oleaginous ointment base
- the concept above is used in the preparation of OPHTHALMIC OINTMENTS; Eucerin is a 50% W/O emulsion
- Hydrophilic Petrolatum, USP
- Aquaphor and Aquabase
- _____ obtained from the wool of sheep (Ovis Aries)
- a purified waxlike substance that has been cleaned, deodorized, and decolorized
- contains not more than 0.25% water
- _____ is a lanolin processed to reduce the contents of free lanolin alcohols and any detergent and pesticide residues
- Lanolin, USP
- Modified Lanolin, USP
- ________ are oil-in-water emulsions commonly called ____
- due to the external phase of the emulsion is aqueous, they are easily washed from skin and are often called _____
- may be diluted with water or aqueous solutions
- can absorb serous discharges
Example of this type of base is Hydrophilic Ointment
- Water-removable bases, creams
- water-washable bases
- do not contain oleaginous components
- completely water washable and often referred to as ______
- mostly are used for incorporation of solid substances
Example: Polyethylene glycol (PEG) ointment, NF
- water-soluble bases
- greaseless
- is a polymer of ethylene oxide and water
- represented by the formula H(OCH2CH2)nOH, in which n represents the average number of oxyethylene groups
(the answer) having average molecular weight below ____ are clear, colorless liquids
Those with molecular weight above ____ are waxlike white materials
Those with molecular weight in between are _____
THE GREATER THE MOLECULAR WEIGHT, THE GREATER THE VISCOSITY
The NF lists the viscosity of PEGs ranging from average molecular weight of 200 to 8,000
General formula for the preparation of 1000g of PEG ointment is: 400g PEG 3350 and 600g PEG 400
- Polyethylene Glycol Ointment, NF (PEG)
- 600
- 1,000
- semisolids
Selection of the base to use in the formulation of an ointment depends on careful assessment of a number of factors, including the following:
- Desired release rate of the drug substance from the ointment base
- Desirability of topical or percutaneous drug absorption
- Desirability of occlusion of moisture from the skin
- Stability of the drug in the ointment base
- Effect, if any, of the drug on the consistency or other features of the ointment base
- Desire for a base easily removed by washing with water
- Characteristics of the surface to which it is applied
True
Ointments are prepared by two general methods:
a) _________ b) __________
__________ - a large glass or porcelain plate or pill tile
__________ - an electric mortar and pestle, or a device called an Unguator
If the components of an ointment react with metal (as does iodine), ______ or ______ may be used
a) incorporation
b) fusion
- ointment slab
- ointment mill
- hard rubber or silicone spatulas
A ________ are used for levigation.
- this allows both reduction of particle size and dispersion of the substance in the vehicle
- after levigation, the dispersion is incorporated into the ointment base by spatulation or with the mortar and pestle until the product is uniform
mortar and pestle
- Natural balsams, such as Peru balsam, are usually mixed with an equal portion of ______ before incorporation into a base. This reduces the surface tension of the balsam and allows even distribution of the balsam throughout the base.
- ___________ can be used to force coarsely formed ointments through stainless steel or ceramic rollers to produce ointments uniform in composition and smooth in texture. Small ointment mills also find use in product development laboratories and in small-batch manufacture or compounding.
- castor oil
- Ointment or roller mills
- By the __________, all or some of the components of an ointment are combined by being melted together and cooled with constant stirring until congealed
- on small scale, this method mat be conducted in a ______ or _______
- on a large scale, this method is carried out in large ________
- fusion method
- porcelain dish or glass beaker
- steam-jacketed kettles
True or False
Fusion Method (Ointments)
By this general process, the materials with the highest melting points are heated to the lowest required temperature to produce a melt.
True
- ## --
- microbial content
- minimum fill
- packaging
- storage
- labeling
