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Ointments- semisolid preparations intended for external
application to the skin
or mucous membranes. May be medicated or unmedicated
Unmedicated- used for the physical effets, provide as
protectants,
emollients or lubricants
Ointment bases- vehicles for medicated ointments
Oleaginous bases
also termed hydrocarbons bases,
have an emollient effect,
protect against the escape of moisture.
Immiscibility with water
Petrolatum, USP
Unctuous mass
Yellowish to light amber color
Melts at 38-60oC
AKA yellow petrolatum and petroleum jelly
Commercial product: Vaseline (chesebrough-ponds)
White petrolatum, USP
Obtained from petroleum that has been decolorized
Same purpose of petrolatum
Yellow Ointment, USP
Obtained from honeycomb of the beeApis mellifera
Greater viscosity than plain petrolatum
Also called simple ointment
Yellow wax 50g
Petrolatum 950g
Absorption bases
Two types: 1.) permit incorporation of aq. Soln resulting in W/O
(water in oil)
2.) permit additional quantities of aq. Soln W/O emulsions
-not easily removed with water
-external phase is oleaginous
Hydrophilic Petrolatum, USP
Commercial product : Aquaphor
Lanolin, USP
Obtained from wool of sheep (Ovis aries)
Purified waxlike substance
0.25% water
Water Removable Bases
- Oils in water bases O/W resembling creams
- Easily removed by water
- Often called water-washeble bases
Hydrophilic Ointment,USP
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1.)Stearyl alcohol and White petrolatum are metled while others
ingr. Are
added with stirring (oleaginous phase)
2.)Sodium lauryl sulfate- emulsifying agent
3.)Propylparaben and methylparaben- antimicrobial agent
4.)Other ingr.- aqueous phase
Water Soluble Bases
- Does not contain oleaginous components
- Completely water washable
PEG or Polyethylene Glycol Ointment, NF
Polymer of ethylene oxide and water
NF list viscosity 200-8000
Combine PEG 3350 and PEG 400
PEG 3350- Solid
PEG 400- Liquid
Selection of appropriate base
Desired release rate of drug substance form ointment base
Desirability of topical drug absorption
Desirability of occlusion of moisture from skin
Stability of drug
Effect
Desire for a base easily removed by water
Characteristics of the surface to which it is applied
Preparation of ointmentsa. Incorporation: Mixed until uniform
preparation is attained
b. Fusion: All or some components of ointment are combined by
melting and
cooled with constant stirring
Compendial Req.
Microbial content
Minimum fill
Packaging
Storage
Labeling
Additional Standards
Viscosity In-vitro drug release
Creams
Semisolid preparations containing one or more medicinal agent
dissolved
or dispersed in either W/O or O/W
Vanishing creams O/W
Primary application in topical skin and rectally and
vaginally
Easy to spread and remove
Gels
Semisolid systems consisting of dispersion of small or large
molecules inand aq. Liquid vehicle rendered jellylike by adding
agelling agent
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Single phase gels: marco-molecules are uniformly distributed
with no
boundaries between the dispersed macromolecules and the
liquid.
Two phase: Gel mass consisting of floccules, often referred to
as magmas
Transdermal Preparations- common is Pluronic lecithin organogel
with a ratio
of 1:5 equal parts of isopropyl palmitate and lecithin.
Miscellaneous semisolid preparations
Pastes
Semisolid intended to the skin
Contain larger portion of solid (25%)
Prepared same as ointments
Stiff, not intended to be applied in hairy areas of the body
Zinc oxide paste ( Lassars Plain Zinc Paste)
Plasters
Solid or semisolid adhesive masses spread on a backing of paper,
fabric,
moleskin, or plastic
Unmedicated provide protection or mechanical support
Medicated effect at the site of application
Salicylic acid plaster for removal of corns in toes (10-40%)
Glycerogelatins
Plastic masses contain gelatin(15%), Glycerin (40%), Water(35%)
and
medicinal substance (10%)
Applied for long term
Melted before application, cooled to slightly above body
temp.
