SAIF ULLAH KHAN

1. POWDERS
DEFINITION:-
Powders are the blend of drugs meant for internal (douche
powder) and external use (dusting powder). Granules can
be made from powders.
(ANSEL’S PHARMACEUTICAL DOSAGE FORMS AND
DRUG DELIVERY SYSTEM)
Advantagesofpowders:-
Stability:-
Powders have good stability with fluids. Powders have
uniform size and uniform area. Powders are stable than
liquid dosage form.
E.g ampicillin
Antibiotic powder dry form= two to three years shelf
life.
Liquid of same antibiotic=one to two weeks
EASY TO SWALLOW:-
Powders can be easily swallow in bulk form or in small
quantity.

2. Rapid dissolution:-
Powders are easily dissolved in the body fluids due
smaller size. Due to smaller size drug bioavailability
increases and decreases gastric irritation as compared
with tablets. Powders diffuses more rapidly than tablets
and pills. Powders have rapid onset of action.
Patients compliance:-
Adults and children can easily swallow powders as
compared to tablets and pills so this shows the patients
compliance. Powders can easily be swallow by some
patients who are unable to swallow other dosage forms
like capsules
Disadvantagesofpowders:-
Hygroscopicity:-
It is difficult to protect powders from hygroscopicity(the
ability of a substance to attract and
hold water molecules from the surrounding environment)
and deliquescent(the process by which a substance
absorbs moisture from the atmosphere until it dissolves in
the absorbed water and forms a solution)
Bitterin taste:-

3. Powders have bitter or unpleasant taste especially herbal
drugs. We say to overcome bitter taste that bitter drugs
are better drugs but it may necessarily be not true
Inconveniently handle:-
Wrapped doses of powers (sachets) are required. This
may increase the manufacturing expense.it is possible to
include a spoon in a packet of powder drug. This may
result in inappropriate dose of drug.
Poorunderstanding forcorrect method ofuse:-
it is difficult to understand the correct method of use.
Without clear instruction, patient may inhale through the
nose a drug meant for oral administration. In oral
administration, it may have to be clear whether the drug
has to be dissolved first in water or taken as it is.
Difficulttocompound:-
Powders are time consuming to compound as compared
to other dosage forms.
Carrier formicroraganism:-
Powders are carrier for microorganisms and chemicals
such as bacteria and toxin
Effectofparticlesizedetermination:-
SIEVING:-

4. Particles are passed by mechanical shaking through a
number of sieves.U.S.P classified particle size on the
basis of sieve numbers (no. of sieves per linear inch)
PARTICLE SIZE SIEVE NUMBER
VERY COARSE 8
COARSE 20
MODERATELY COARSE 40
FINE 60
VERY FINE 80
MICROSCOPY:-

5. We can determine particle size with the help of
microscope. There are different types of microscopes.
Some are:-
 Transmission electron microscopy
 Scanning electron microscopy
 Atomic force microscopy
OTHER METHODS:-
LIGHT SCATTERING(less than1micrometer)
Dynamic light scattering technique(DLS)
Coutler counter
Sedimentation rate
Permeability method
Laser diffraction analysers
Laser holography
Electron particle counter
EFFECT OF PARTICLE SIZE:-
 DISSOLUTION RATE:-
If particle size of powder is decreased,the rate of drug
dissolution and its bioavailability will also be increased.
 SUSPENDIBILITY:-
By decreasing the size, we can increase the
suspendibilty of drug in the liquid.
 UNIFORM DISTRIBUTION:-

6. If particle size of drug is decreased, uniform distribution
of drug substances will be increased.
 PENETRATION:-
Penetration of drug is increased by decreasing particle
size like in aerosols.
 GRITTINESS:-
By decreasing particle size of powder,grittiness will be
decreased like in dermal ointments,creams and
ophthalmic preparation.
METHOD OF MIXING OF POWDERS:-
 SPATULATION:-
In this process, we need spatula to mix the powder on an
ointment tile or paper. This method is suitable for eutectic
mixtures. Eutectic mixture is formed by the substances
when combined include phenol, aspirin, menthol etc.
 TRITURATION:-

7. Mortar and pestle is required for this process. This
process is used for small scale mixing. Trituration is for
mixing as well as reduction of particle size.
There are different types of mortars include glass mortars,
Wedgwood mortar and porcelain mortars.
 SIFTING:-
Particles are passed through a series of sieves. After
shaking mechanical shaker, particle are collected through
different sieves. If particles are collected in a sieve having

8. sieve number 80, there will be fine particles.
 TUMBLING:-
Tumbling is a device which homogenizes the powder.
It consist of electric motor, metallic vessels and baffles.
Tumblers typically operate at speeds of 5-25 rpm.

9. Tumblers are of different shapes. Some are
 Cubical shape
 V shape
 Y shape
 Cylindrical shape
 Double cone shape
 TYPES OF POWDER:-
On thebasisofactiveingredients:-
 Simplepowder
 Compoundpowder
Simple powder:-

10. Simple powders have only one active ingredient either in
crystalline form or amorphous form. When they are in
crystalline form they are converted into fine powders.
Weigh the powder, divided into number of doses and then
wrapped into individual doses.
example:-
aspirin powder
aspirin----300mg
DIRECTION: after every 8 hrs one powder to be taken
Compound powder:-
These powders have two or more than two components
and then divided into desired number of individual dose
and dispensed into each powder paper.
example:-
powder of A.P.C
Aspirin-------------300mg
Paracetamol-----150mg
Caffeine ----------50mg
On thebasisofdispensing:-

11. Bulkpowder:-
Bulk powders may be classified as dentrifices, oral
powders, dusting powders, trituration, insufflations, and
douche powders.
 ORALPOWDERS:-
These powders are dissolved in water or mixed with soft
food, prior to administration. Laxative and antacid powders
are in this form.
 DUSTINGPOWDERS:-
They are applied on skin. They have no systemic action.
REQUIREMENTS:-
 Free from irritation.
 Flow easily
 Homogenous and very fine
 Have good absorptive adsorptive capacity
 Spread uniformly over body surface
 Cling to body surface after application
 INSUFFLATIONS:-

12. These powders are introduced into the body cavities such
as nose, throat, tooth sockets, ears, and vagina. An
insufflator or powder blower is used for the introduction of
these powders.
Norisodrine sulfate aerohaler cartridge(Abbot) is an
example.
DOUCHE POWDER:-
These powders are dissolved in water prior to use as
antiseptics or cleansing agents for a body cavity. They are
meant for vaginal use, nasal, ophthalmic use. Aromatic
oils are also included in these powders.
DENTIFRICES:-
These powders an anticariogenic agent (agent which
interferes the development of dental caries)
DIVIDED POWDERS:-

13. These are in the form of individual doses and dispensed in
folded paper (chartulae). They are dispensed in metal foil,
small heat sealed plastic bags or other containers.
EXAMPLE IS Head ache powder and laxative powder.
PACKAGING OF POWDERS:-
Packaging takes place in two ways:
1. DIVIDED POWDER PACKAGING OR UNIT DOSE
PACKAGING:
controlled rate and dosage.
wrapped in a paper to enclose the
required amount for single dose.
envelopes or boxes.
etc then an inner wrapper of
parchment is necessary.
2. BULK PACKAGING OR MULTIDOSE PACKING:
or bottles wuth mouth sufficiently
wide to take tea spoon as required.

14. References:-
 (ANSEL’S PHARMACEUTICAL DOSAGE FORMS
AND DRUG DELIVERY SYSTEM).