creams ms.wajiha iffat objectives: after the end of this topic, the student will be able to : define...
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CREAMSCREAMSMS.WAJIHA IFFATMS.WAJIHA IFFAT
OBJECTIVES:
After the end of this topic, the student will be able to :
•Define creams•Classify creams •Method of preparation•prepare a cream from first principles• incorporate solids and liquids into a cream base
Creams Creams BP DEFINES : “Creams are formulated to provide
preparation that are essentially miscible with skin secretion. they are intended to be applied to the skin or certain mucous membranes for protective ,therapeutic, or prophylactic purposes especially when occlusive effect is not necessary.”
CreamsCreamsIn USPXVIII ,creams are defined
as“ semisolid emulsions of either oil
in water or water in oil type.”“ semisolid emulsions usually
medicated ,intended for external application.”
CreamsCreamsAqueous cream: aqueous cream ,
cetrimide cream, cetomacrogol creamOily cream: oily cream /hydrous
ointmentCosmetic creams:All purpose cream, baby cream,
barrier cream, bleaching cream, cleansing cream cold cream, hair cream, hand cream, vanishing cream.
Medicated creams:
CreamsCreamsCreams are reserved for external
preparation.A cream may be water in oil or oil in
water depending on the emulsifying agent used.
They are soft ,easy to apply ,cooling to skin ,easily water-removable.
w/o cream: oily creams Contains: emulsifying agents of natural
origins( bees wax, wool alcohols, wool fatproperties :Emollient.Creamy, white or translucent and
stiff.
CreamsCreams
o/w creams: aqueous creamsContains: synthetic waxes e.g., cetomacrogols & macrogols Properties:Causes rapid absorption &
penetrationThin ,white & smooth consistency
CreamsCreamsMETHOD OF PREPARATION:TRITURATION:Used for finely divided insoluble powder
particles or liquidsinsoluble powder are added by
geometric dilutionLiquids are added by making well in
centre.Air pocket formation avoided.Involved the use of glass slab when small
quantities are usedMortar and pestle used when we have
large quantities.
CreamsCreamsLEVIGATION:
Incorporation of insoluble coarse particles.
Also known as “Wet grinding”.insoluble coarse powder is rubbed
with molten base or liquid or a semi solid base.
A considerable shearing force is applied to avoid grittiness.
CreamsCreamsHygiene: ( aseptic condition)All equipment & spatula to be cleaned by
IMS. (70% ethanol should be used)Determine the miscibility of the substances
being incorporated.Melt the fatty base .substances with the
highest melting point to be melt first. These bases then cooled to 60°C.
Temperature of the aqueous phase to be adjusted to 60°C.
The disperse phase to be incorporated to the continuous phase at the same temperature.
Avoid air pockets & hasty cooling.
CreamsCreamsIncorporation Of solid
Ingredients Into Cream Base:Solid particles can be
incorporated after the bases coolsSoluble solids: added to the
molten cream at the lowest possible temperature& the mixture stirred until cold.
Insoluble solids: incorporated by using tile & spatula or mortar and pestle using doubling technique.
CreamsCreamsCoarse powder: minimum
quantity of cream should be placed in the centre of the tile & used to levigate the powders.
Fine powders : may be triturated to into other wise finished creams on ointment tile. (geometric dilutions.
CreamsCreamsIncorporation Of Liquids:Non volatile ,miscible liquids: may
be mixed with molten cream in evaporating basin. if a pre-prepared base is used then follow procedure for volatile or immiscible liquids.
Volatile or immiscible liquids:E.gs coal tar should be triturated with
creams on tile .a very small amount of creams should be placed on tile and a well made in centre. small quantities are folded gently to avoid splashing.
CreamsCreamsDiluted creams:If the diluents is stated in the
manufacturer data sheetFreshly preparedNo heating should be involved.Should be carried out in aseptic
conditions.Should not be used more than 2
wks.
REFERENCESREFERENCESCompounding and Dispensing by
Christopher A Langley & Dawn Belcher pg. 65-91.
Compounding and Dispensing by john F. Marriot, Keith A. Wilson Christopher A Langley & Dawn Belcher pg.147-151
Pharmaceutical Practice by D M Collett pg:116-117
Sprowls’ American Pharmacy pg:273-274
Pharmaceutics practice by Winfield.