Classification of Powders

1. CLASSIFICATION OF
POWDERS
RESHMA FATHIMA K
ASSISTANT PROFESSOR
GRACE COLLEGE OF PHARMACY

2. Bulk Powders for external use
• Bulk powder meant for external use are non potent substances. These
powders are supplied in cardboard, glass or plastic containers, which
are often designed for the specific method of application. The dusting
powders are preferably supplied in perforated or sifter top containers.
The container should bear a label indicating that the powder is meant
for external application.

3. • The bulk powders which are commonly used for external applications
are as follows:
• Dusting Powders
• Insufflations
• Snuffs
• Dentifrices

4. Dusting powders
• These are meant for external application to the skin and are generally
applied in very fine state of subdivision to avoid local irritation. Hence
dusting powders should be passes through sieve no: 80 to enhance
their effectiveness.
• Dusting powders are of two types:
• Medical
• Surgical

5. • Medical dusting powders are used mainly for superfacial skin
conditions, whereas surgical dusting powders are used in body
cavities and also on major wounds as a result of burns and umbilical
cord of infants.
• Surgical dusting powders must be sterilized before their use, whereas
medical dusting powders must be free from pathogenic
microorganisms.

6. • Dusting powders are generally prepared by mixing two or more
ingredients one of which must be either starch, talc or kaolin as one
of the ingredients of the formulation. Talc and Kaolin are more
commonly used because these are chemically inert
• Dusting powders are dispensed in sifter top container or aerosol
containers.
• Dusting powders are generally considered to be non toxic but the
inhalation of its fine powdered ingredients by infants may lead to
pulmonary inflammation. So proper care must be taken while
handling these preparations.

7. • It is mainly used for their antiseptic, astringent, absorbent, and
antipruritic action.
• Dispense 50g of dusting powders
• Rx
• Purified talc, sterilized 50.0g
• Starch in powder 25.0g
• Zinc oxide in powder 20.0g
• Salicylic acid in powder 5.0g
• Make a powder

8. • Direction: Applied on the affected part two or three times a day
• Method: Powder all the ingredients. Weigh the required quantity of
purified talc, starch, zinc oxide and salicylic acid. Mix them in
ascending order of their weight. Pass the mixed powder through a
sieve no 85. after sifting again mix lightly. Transfer the powder in sifter
top containers to protect it from atmospheric contaminations.

9. Insufflations
• These are medicated dusting powders meant for introduction into the
body cavities such as ear, nose, vagina and throat with the help of an
apparatus known as “ insufflator”
• It sprays the powder into a stream of finely divided particles all over
the site of application. The following difficulties are however generally
faced while using the insufflators.
It is difficult to obtain a measured quantity of the drug as a uniform
dose.
It gets blocked when it is slightly wet or the powder used is wet

10. • Insufflations are used to produce a local effect, as in the treatment of
ear, nose and throat infection with antibiotics or to produce a
systemic effect from a drug that is destroyed in the gut.
• Snuffs
• These are finely divided solid dosage forms of medicament which are
inhaled into nostrils for its antiseptic, bronchodilator and
decongestion action.
• Snuffs are dispensed in flat metal boxes.

11. • Dentifrices
• These are applied with the help of a tooth brush for cleaning the
surface of the teeth. They contain a suitable detergent or soap, some
abrasive substance and a suitable flavor. The abrasive agents such as
calcium sulphate, magnesium carbonate, sodium carbonate and
sodium chloride are used in fine powder.
• A strong abrasive substance should however not to be used as it may
damage the tooth structure.

12. • Dispense 50.0g of dentifrices
• Rx
• Hard soap, in fine powder 50.0g
• Precipitated calcium carbonate 935.0g
• Saccharin sodium 2.0g
• Peppermint oil 4.0g
• Cinnamon oil 2.0ml
• Methyl salicylate 8.0ml
• Make a tooth powder

13. • Direction: To be applied on the surface of the teeth with the help of
tooth brush.
• Method: Triturate the saccharin sodium, the oil and methyl salicylate
with about one half of the precipitated calcium carbonate and mix
the soap with the remaining portion of the precipitated calcium
carbonate. Mix the two powders thoroughly and then pass it through
a fine sieve.

14. • Simple and Compound Powders for Internal use
In this form of powder, each individual dose is enclosed in paper. The
number of ingredients may be one (simple powder) or more than one
powder (compound powder). The minimum quantity of each powder
should not be less than 100mg so that it can be handled conveniently
by patient and can be weighed accurately. The following rules should
be observed:
Weigh the ingredients after calculating for one extra powder.
If the quantity of an ingredient is not directly weighable, calculate for
sufficient extra powders to produce directly weighable quantity.
In case of potent ingredient, calculate the amount of lactose to be
mixed to make each powder directly weighable.

15. Simple powder
• A simple powder contains only one ingredient either in crystalline or
amorphous form. When the powder is in crystalline form, it is
reduced to fine powder, weighed the powder and divided into
number of doses and wrapped as individual doses.
• Dispense six powders of aspirin each powder contains 300mg of
aspirin.
• Rx
• Aspirin 300mg
Make a powder
Direction: One powder to be taken after every eight hours

16. • Method:
• Powder the aspirin and weigh the required quantity of aspirin. Weigh
300mg of aspirin for each powder. Wrap each dose in individual
powder paper. Prepare six such powder. Pack it flap to flap and
restrained with elastic band.
Compound Powders
Compound powders contain more than two substances which are
mixed together and then divided into desired number of individual
doses which are dispensed into each powder paper.
Dispense eight powders of A.P.C
Rx
Aspirin 300mg
Paracetamol 150mg
Caffeine 50mg Make a powder

17. • Direction: One powder to be taken when need arises
• Method: Powder all the ingredients and weigh the calculated quantity
of each ingredient. Mix them in ascending order of their weight.
Weigh 500mg of the mixed powder for each powder. Wrap each dose
in individual powder paper. Pack in pairs flap to flap and restrained
with elastic band.

18. • Cachets consists of a dry powder enclosed in a shell. The shell is
prepared from a mixture of rice flour and water by moulding into
suitable shape and then dried.
• Two types of cachets are there:
• (i) Wet seal cachets: lower half of the cachet is filled with powdered
drug. Then the flange of the empty upper half of the cachet is
moistened with water, and pressed over the lower half. The cachet is
dried for 15 minutes.

19. ii)Dry seal cachets:
• Drug powder is filled in the lower half and the upper half is pressed
over it just like a capsule.
Use:
• They are used for administering the drug with unpleasant taste and a
large dose. Before administration, a cachet should be immersed in
water for few seconds and then placed on the tongue and swallowed
with water.
• e.g. Sodium aminosalicylate cachets
Sodium aminosalicylate and isoniazid cachtets

21. • Packing and storage of cachets: The cachets are packed in boxes or
tins in which they are placed on their edges or lying flat. The
container containing cachets should be labelled with a direction for its
use; immerse in water for a few seconds and then swallow with a
draught of water.

22. Tablet Triturates
• These are powders molded into tablets. Molded tablets are flat, circular disc and usually contains a
potent substances which is mixed with lactose, dextrose or some other suitable diluent. The
apparatus used for the preparation of tablet triturates is made of stainless steel or plastic.

23. • It consists of an upper perforated plate which is having an exactly the
same no of holes as that of number of pegs in a lower plate. The
lower plates also have two large pegs which ensure correct fitting of
the plates. The molds arev