OINTMENTS
MS. WAJIHA IFFAT
After completing this lesson, you should be able to:
•Define The Term Ointment
•List Down The Desirable Characteristics Of Ointment Bases
Classify The Ointments &/Or Ointment Bases .
• Differentiate Different Type Of Substance That Should Be Used As An
Ointment Base.
•Select The Procedure That Should Be Used To Prepare An Ointment Using
The Fusion Method Or Incorporation Method.
•Select The Auxiliary Label That Should Be Placed On A Container In
Which An Ointment Is Dispensed.
OINTMENTS
• DEFINITION:
• “Ointments are semisolid preparation intended for
application to the skin with or without inunction. they may
be oleaginous e.g., white ointment; they may be entirely
free of oleaginous substances e.g., polyethylene glycol
ointment, or they may be emulsions of fatty or wax like
material containing relatively high proportion of water e.g.,
hydrophilic ointment.”
OINTMENTS
• IDEAL OINTMENT BASE:
• According to BEELER, ideal ointment base should have following
physicochemical properties:
1. Stability
2. Neutral in reaction
3. Non greasy
4. Non degreasing
5. Non irritating
6. Nondehydrating
7. Non hygroscopic
8. Water removable
9. Compatible with all medicaments
10.Free from odors
OINTMENTS
11. Nonstaining
12. Efficient on all skin type
13. Composed of readily available component of known
chemical composition
14. Capable of holding 50% of water
15. Easily compounded
16. Melting & softening at body temperature
17. smoothness
18. ease of application
19. Suitable base
20. Properly distributed medicament
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
ACCORDING TO PENETRATION:
1.EPIDEMIC OINTMENT :
• Slight penetration power
• Therapeutic effect on diseased epithelium
• e.g,petrolatum,waxes and 1+2.
2.ENDODERMIC OINTMENT:
• Power of deeper penetration
• e.g,vegi oils,lards,lanolin and 1+2+3
3.DIADERMIC OINTMENT:
• Penetrate skin effectively. better absorption
• e.g., emulsion type & water soluble.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
CLASSIFICATION ACCORDING TO CHEMICAL
COMPOSITION:
(PHYSICAL CLASSIFICATION ):
They may be classified into four main groups:
• Hydrocarbon Bases
• Absorption Bases
• Water Miscible Bases
• Water Soluble Bases
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• HYDROCARBON BASES:
(a) Properties.
1.Anhydrous
2.Do not absorb water readily (Hydrophobic)
3. Insoluble in water
4.Not washable
(b) Examples. Fats and fixed oils such as lard, olive oil, cottonseed oil,
petrolatum(soft paraffin), white ointment, Yellow Ointment (Bees
Wax) and silicon bases.
(c) Advantages. Highly compatible; occlusive; good emollients.
(d) Disadvantages. Difficult to remove from skin and clothing; uncertain
as to yield of medicament.
May go rancid . allergies??
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• ABSORPTION BASES:
They may be:
• Non emulsified: they absorb water and aqueous
solutions to produce w/o emulsions. Examples are
wool fat (anhydrous lanolin), wool alcohols, bees
wax and cholesterol.
• w/o emulsions: they are similar in properties to the
previous group and are capable of absorbing more
water. Examples are hydrous wool fat B.P. (lanolin)
and oily cream B.P.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
(a)Properties.
• Anhydrous
• will absorb water( hydrophillic)
• Insoluble in water
• most are not washable.
(b)Example. Hydrophillic Petrolatum, USP; Anhydrous
Lanolin, USP.
(c) Advantages. Highly compatible; relatively stable
to heat; can be used in anhydrous form or water
can be added when emolliency is desired.
(d)Disadvantage. Greasy. Less occlusive.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• EMULSION BASES:
A. Emulsion Ointment Base (W/O):
1. Hydrous
2. Will absorb water
3. Insoluble in water
4. Not washable
5. Water-Oil-Emulsion
6. Examples—Lanolin, Rose water Ointment, Cold Cream
B. Emulsion Ointment Base (O/W):
1. Hydrous
2. Will absorb water
3. Insoluble in water
4. Washable
5. Oil-in-Water Emulsion
6. Hydrophilic Ointment
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• Emulsion Bases. Emulsion ointment bases consist of an
aqueous phase, an oleaginous phase, and an emulsifying
agent. They are true, solid emulsions.
• Emulsion bases may be either oil-in-water (o/w) or waterin-oil (w/o), usually depending upon the phase in which the
emulsifier is more soluble. The water phase varies from 10
percent to 80 percent of the completed ointment base.
• They can be anionic, cationic, nonionic.
• Combination:30:soft paraffin50: liquid paraffin20
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• (1) Preparation. Emulsion bases are made by
melting the greasy and oily materials together in
one container and heating the water and watersoluble materials in another container.
• At the temperature of 75° C, they are mixed
together until a smooth cream results. While the
mixture is still warm and thin, it may be passed
through a homogenizer to improve the appearance
and quality of the base.
• The mixture is then stirred until it congeals.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
Summary of emulsion bases. We can sum up the
important aspects of emulsion bases as follows:
(a) Properties. The w/o emulsion bases are insoluble
in water and are not washable; the o/w emulsion
bases are washable and nongreasy.
(b) Example:
• Lanolin, USP (w/o);
• Hydrophilic Ointment, USP (o/w);
• Vanishing creams (o/w).
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
(c)Advantages:
• Washable and nongreasy if oil-in-water (o/w).
(d) Disadvantages:
• Subject to water loss if o/w,
• greasy and unwashable if water-in-oil (w/o),
• unless, a preservative is added, the
emulsion bases are subject to mold growth.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
• Water-Soluble Bases.
• The polyethylene glycol polymers, or Carbowaxes, are of
great importance in ointments.
• The names of the Carbowaxes include numbers that
roughly indicate their average molecular weight.
• Carbowaxes with a molecular weight in the area of 1,000
are soft, ointment-like substances.
• As the molecular weight increases, they become harder
and they finally become waxes. They are water-soluble,
nonvolatile, and do not deteriorate or support mold
growth.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
•
•
•
•
•
•
Properties:
Anhydrous
but will absorb water and dissolve in water;
Washable
Non-greasy.
(b) Examples. Carbowax compounds such as the
polyethylene glycol bases containing pectin,
cellulose, Bentonite, and gelatin.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
c) Advantages. Wide range of compatibility;
• do not become rancid or support microbial
growth;
• nonirritating (to the same degree as lanolin,
petrolatum, etc);
• adhere well to skin;
• easily washed off;
• low incidence of sensitization.
(d) Disadvantages. Sometimes undergo gradual
discoloration with certain drugs.
• Unless cetyl alcohol is added, an aqueous solution
can be added only to the extent of 5 percent.
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
•
LANE & BLANK CLASSIFICATION:
According to physicochemical action of vehicle on
skin:
1. VEHICLE ACTED AS AQEOUS MIXTURE
2. VEHICLE ACTED AS OILS
3. VEHICLE ACTED AS POWDERS
4. VEHICLE ACTED AS ORGANIC SOLVENT
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
CHEMICAL CLASSIFICATION:
1. Hydrocarbon
2. Alcohol
3. Acid
4. Ester
5. SOAPS
6. MISCELLANEOUS
CLASSIFICATION OF OINTMENT/ OINTMENT BASES
ACCORDING TO USES OR THERAPEUTIC
CLASSIFICATION:
1. Emollient
2. Protective
3. Anti Infectives
4. Anti Eczematic
5. Keratolytic
6. Anti Prespirants
7. Anti Sebhorrics
METHOD OF PREPARATION
• MIXING BY FUSION:
• In this method, the ingredients are melted
together and stirred to ensure homogeneity.
• On a small scale, fusion is usually fusion is
usually carried out in an evaporating basin
made of glazed porcelain or stainless steel
over a water bath.
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•
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METHOD OF PREPARATION
PREPARATION OF OINTMENT BASE BY FUSION:
The constituents of the base are melted together in the
basin and stirred gently after melting until cool.
Vigorous stirring can cause aeration which should be
avoided.
Any foreign particles that are naked on melting cam be
removed by decantation or by using a warm muslin cloth.
If product is granular after cooling due to separation of
some ingredients of high MP, it may be remelted with min.
heat and restirred until cold.
Stock bases can be made successfully by pouring the
melted mixture into a warmed jar, covering and allowing to
stand, undisturbed on a non conducting surface, until set.
(paraffin, simple or wool alcohol ointments of B.P.)
METHOD OF PREPARATION
• Completely or partially soluble solids should be added in
fine powder to the molten base at very low temperature
and the mixture stirred until cold.
• Liquids such as methyl salicylate and coal tar solutions and
semi solids such as ichthammol should be added just as the
base is thickening, at about 40C. When a solid is soluble in
liquid ingredient, (menthol in methyl salicylate), its more
convenient to add it in solution.
• Insoluble solids (calamine, starch, zinc oxide) should be
passed through a 180 um sieve and added in small amount
while stirring to melted base, when it shows first sign of
thickening. Sedimentation should be prevented.
• If the product has liquid paraffin or a fixed oil, small
amount can be used to levigate powder before adding to
base to produce a smoother product.
METHOD OF PREPARATION
• MIXING BY TRITURATION:
• This is applicable when medicament is a solid
insoluble in base or a liquid present in small
amount.
• Solids should be finely powdered and passed via
sieve. (250 um/180 um/125 um mesh).
• Trituration can be carried out with an ointment tile
and a spatula or using mortar and pestle.
METHOD OF PREPARATION
• TRITURATION
USING
TILE
AND
SPATULA:
Tiles should be large enough to prepare ointments.
• Spatula should be flexible and have a broad, non-tapering long blade,
to provide a large rubbing surface.
• Another small spatula may be used for removing accumulated
material.
• Powders for incorporation are placed on the tile and mixed gently.
• Powders are levigated until mixture is smooth and homogenous.
• Dispersion is then diluted with increasing amounts of base, doubling
the quantity on each addition.
• Finally any liquid ingredients are incorporated, avoiding splashes.
METHOD OF PREPARATION
• TRITURATION USING MORTAR AND PESTLE:
• The mortar should have a flat base and the pestle is flat
headed to give best results.
• Warming equipment can be helpful if the base is very stiff.
• Sequence of mixing is same as for the tile method.
• Splashing of liquids is easily controlled in the mortar.
METHOD OF PREPARATION
• Incorporation of solids
• Incorporation of gummy materials.
• Incorporation of liquids.
• PACKAGING,STORAGE& LABELLING:
REFERENCES
• Sprowls’
American
Pharmacy
By
Lewis.W.Dittert.Pg-233-277.
• Pharmaceutical Practice By Diana M. Collett
pages 125-133
• Ansel’s Pharmaceutical Dosage Form & Drug
Delivery System By Ansel Pg.277-293
• Pharmaceutical Practice By A.J Winfeild.pg.206217
• Pharmaceutical Pre Formulation & Formulation
Pg:515-569
OINTMENTS
• THANK YOU.
• ANY QUESTION ??
• Prepare an assignment on types of ointment
bases along with their official formula and
method of preparation. one example each.