Compounding
Powders
(Pulvis et Pulveres)
Dr. Muslim Suardi, MSi., Apt.
Faculty of Pharmacy University of Andalas
Pharmaceutical Powder
“a mixture of finely divided drugs or
chemicals in a dry form meant for
internal or external use”
Powder
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The word "powder" refers to a chemical
or mixture that is solid in physical state.
In compounding, "powder" refers to a
dosage formulation that is solid in
physical state. But the formulation may
be composed of only the active drug or
may be a mixture of the active drug &
other ingredients.
Powder
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Frequently prescribed by physician
Divided powders
Bulk powders
Dusting powder
Capsules
Granules
Types of Pharmaceutical
Powders
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Oral powders
Topical powders, Dusting powders
Powders for inhalation
Insufflations powders as a starting
material
Caps, Tab Dispersions, Injections
Suspensions reconstituted
Advantages
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Wide choice of ingredients & varying
doses can be prescribed to fulfill the
individual patient needed
It is convenient for the physician to
prescribe a specific amount of powder
Each dose can contain a different
amount of active drug
Easy to carry
Advantages
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Fewer incompatibility than in liquids
Since small particle size & no
desintegration step look like tablets,
dispersion of ingredients will be rapid
A greater & more rapid dissolution in
the stomach
On set of action is faster as compared
to tablet, capsules, because it is easily
in dissolved in body fluids
Advantages
Advantages
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When it is not possible to dispense a
drug as a solution or a suspension,
because of its insolubility or because it
is susceptible to microbial
contamination if it is wetted, then it is
a good idea to dispense it as a
powder.
Easy administration to the patient
orally by dissolving in suitable liquids
Advantages
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When the patient has to mix the
ingredients before administration,
dispensing in separate divided
powders is a convenient way.
Bulky doses or large volume can be
more easily taken by the patient, it
mean a powder is a good way of
administering it.
Advantages
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It can be administered easily to
infants, young children, geriatry or
other patients who cannot swallow
tablets or capsules. In such situations
powders are a good option.
Flexibility of compounding.
Advantages
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Good chemical stability related with
moisture, oxidized, & interaction.
Drugs tend to most stable as a solid
It is more stable than liquid dosage
form.
Advantages
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It is used both internally & externally
Can be applied to many body cavities:
ears, nose, tooth socket, throat
Can be made into many different
dosage formulations: capsules, tablets,
powders for reconstitution, dusting
powders, bulk powders, powders for
inhalation, etc.
DISADVANTAGES
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Time-consuming preparation
Quantity <100 mg cannot be weighed
conveniently
Inaccuracy of dose (size of measuring
spoon, density of powder, humidity,
degree of settling, fluffiness).
Unsuitability for many unpleasant tasting,
hygroscopic & deliquescent drugs.
DISADVANTAGES
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Bitter taste, nausea & unpleasant taste
drugs can’t be administered in powder
form. Deliquescent & hygroscopic
drugs can’t be dispensed in powder
form they are packed in double
wrapping. Drugs which get affected by
atmospheric condition aren’t suitable
for dispense.
List of Mesh Sizes
Mesh Size Number
Mesh Opening Size
Mesh Opening Size
Millimeters
Microns
2
9.52
9520
10
2.00
2000
20
0.84
840
40
0.42
420
60
0.250
250
80
0.177
177
100
0.149
149
200
0.074
74
Usage Based Classification
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Divided Powders (Pulveres)
Bulk Powders (Pulvis for internal used)
Dusting Powders (Pulvis adspersorius)
Douche Powders
Insufflations
Powder Sprays
Dental Powder (Pulvis dentrificius)
Size Based Classification
Description Term
Mesh Opening Size (microns)
Mesh Size Number
> 1000
2 - 10
Coarse
355 -1000
20 - 40
Moderately Coarse
180 - 355
40 - 80
Fine
125 - 180
80 - 120
Very Fine
90 - 125
120 - 200
Very Coarse
Reducing Particle Size
Objectives: Uniform & finely divided
mixture.
Methods:
 Trituration
 Spatulation
 Sifting
 Tumbling
Trituration
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Mortar methods, (mortar & pestles, or
mortir & stamfer)
Most frequently
Used for both pulverization & mixing
Glass mortars are preferred for dyes &
highly colored materials
Spatulation
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Used to mix small quantities of
powders & combination of powders
having the same densities.
A powder spatula is used as the
mixing instrument, & the powders are
stirred on a pill tile or piece of clean
paper.
Sifting
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Sifting is an excellent way to mix
powders that resist mixing by trituration.
Exceedingly light powders such as MgO
& charcoal can be rapidly & completely
mixed by shaking them through a sieve.
Any large particles which do not pass
through the sieve should be powdered
by trituration & then re-sieved.
Tumbling
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Mixing powders together by shaking or
rotating them in a closed container.
This is a simple mixing process & does
not effect any reduction in particle
size.
Mixing
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Crystalline salts, even if already
powdered, are mixed best by trituration.
Chlorobutanol & phenyl salicylate
electrify & stick or fly when rubbed
Salts with contain much water of
crystallization , such as alum, sodium
phosphate, etc., may need to be dried
before mixing, to prevent reactions.
Powerful Remedies
Mixing
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An equal bulk of diluent with the
potent drug is first placed in the
mortar & triturated until well mixed,
then a double volume more of added
& mixed before a further quantity is
added.
Incompatible Salts Mixing
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Should be mixed lightly, as pressure
may start a reaction.
Rolling on a sheet of paper is a
convenient method for avoiding
pressure.
Eutectic Mixtures
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When phenols or phenolic compounds,
aldehyde compounds & ketonic bodies
are mixed, the mixture may have a
melting point considerably below that of
any of the individual ingredients
A suitable remedy for most eutetic
mixtures is the addition of an inert
powder to separate the offending
powder.
Bulk Powders
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Nonpotent & can be dosed with
acceptable accuracy & safety using
measuring devices such as the
teaspoon, cup, or insufflator
This practically limits the use of orally
administered bulk powders to
antacids, dietary supplements,
laxatives, & a few analgesics.
Many bulk powders are used topically.
Dispensed in Bulk Powder
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Powders which are applied externally
as antiseptic or dusting powders
In relatively large doses such as a
teaspoonful at a time
Some powders used to make
solutions.
Dosage Bulk Powder
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Usually measured out by the patient
All other forms of powder the dosage
is measured & package by the
pharmacist.
Bulk Powder
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Dispense in either cardboard glass
containers.
Topically powders: special shaker-top
boxes are used
Drug to be taken u.i, glass wide-mouth
bottles of appropriate size are the
containers of choice.
Bulk Powder
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When volatile oils or aromatic
substance are contained in the
prescription, air-tight containers
should be used.
Appropriate auxiliary labels should be
used on bulk powders for u.e.
Dusting Powders
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Dusting powders are fine medicinal
(bulk) powders intended to be dusted
on the skin by means of sifter-top
containers.
A single medicinal agent may be used
as a dusting powder; however, a base
is frequently used to apply a medicinal
agent and to protect the skin from
irritation and friction.
Dusting Powders
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Bentonite, kaolin, kieselguhr, MgCO3,
starch, & talc are used as inert bases
for dusting powders.
Powder bases absorb secretions &
exert a drying effect, which relieves
congestion & imparts a cooling
sensation.
Dusting Powders
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All extemporaneous dusting powders
should be passed through a 100-200
mesh sieve to ensure that they are grit
free and will not further mechanically
irritate traumatized areas
Douche Powders
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Used to prepare solutions that cleanse
the vagina.
Most of them are used for their
hygienic effects, but a few contain
antibiotics.
Prescribed as a matter of convenience
for the patient, since a powder is more
portable than a bulky solution.
Douche Powders
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The formula is developed so that a
teaspoonful or tablespoonful of
powder dissolved in a specified volume
of water provides the desired
concentration.
The pH usually ranges from 3.5 to 5
when the solution is prepared.
Feminine bulb syringes or fountain
syringes are used for vaginal irrigation.
Douche Powders
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Since many of the ingredients are
volatile (e.g., menthol, thymol, &
volatile oils), douche powders should
be packaged in glass jars with a wide
mouth.
Some commercial are available in
metal foil packets, which contain the
proper amount of powder for a single
douche.
Insufflations
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Extremely fine powders to be
introduced into body cavities.
To administer an insufflation, the
powder is placed in the insufflator, and
when the bulb is squeezed, the air
current carries the fine particles
through the nozzle to the region for
which the medication is intended.
Insufflations
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All extemporaneously compounded
insufflations must be passed through a
100 mesh sieve.
Pressurized packages provide an
elegant approach to the administration
of insufflations.
Powder Sprays
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In contrast to dusting powders,
powders dispensed under pressure will
deliver targeted and uniform
application at the desired site.
Also, in an aerosol container
medicated powders may be
maintained in a sterile condition.
Powder Sprays
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The powder particles must be a
definite size range to prevent clogging
of the valve orifice and to provide
uniformity of application.
In general, powders that are to be
packaged as powder sprays must not
contain particles greater than 50
microns if they are to be sprayed
successfully.
Divided Powders
(Pulveres)
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Divided powders or charts are single
doses of powdered medicinals
individually wrapped in cellophane,
metallic foil, or paper.
The divided powder is a more accurate
dosage form than bulk powder
because the patient is not involved in
measurement of the dose.
Divided Powders
(Pulveres)
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Cellophane and foil-enclosed powders
are better protected from the external
environment until the time of
administration than paper-enclosed
powders.
Divided powders are commercially
available in foil, cellophane or paper
packs.
Granulations
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Particles ranging in size from about 410 mesh.
Generally made by first blending the
powders together & then moistening
the mixture to form a pasty mass.
The mass is passed through a sieve &
then dried in air or in an oven.
Granulations
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They are prepared as a convenience
for packaging, as a more stable
product due to less surface exposure,
& as a popular dosage form.
Granulations are also used as
intermediates in the preparation of
capsules & tablets, since they flow
more smoothly & predictably than do
small powder particles.
Granulations
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The most popular compounded
granulation is the effervescent powder
(sometimes called effervescent salts).
They are popular due to their taste &
psychological impression.
When added to water, the granulation
effervesces ("fizzes") as CO2 is
liberated.
Preparation of
Effervescent Granulation
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It has been found that citric acid
monohydrate & tartaric acid used in
the certain ratio, produces a powder
with good effervescent properties.
Citric acid monohydrate is not used
alone because it results in a sticky
mixture that will not easily granulate.
Effervescent Granulation
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Tartaric acid is not used alone because
the granules are too friable & crumble
The amount of NaHCO3 to be used
may be calculated from the reaction
which occur when the granules come
in contact with water.