It's described about powder dosage form

1. SOLID DOSAGE FORM
PreparedBy:
Lecturer:Mr. S. S. Mistree
M-pharm(P’ceutics)
Sub:Pharmaceutics-II
IshwarDeshmukhInstitute of Pharmacy, Digras
Yavatmal-445302
2020-21

2. CONTENTS
Introduction
Powder
Classification of powder
Dispensing of powders involving
special problems
Weighing techniques
Reference

3. INTRODUCTION
 It is available in unit dosage form ( which are taken by number).
 This is the most stable and reliable dosage form than any other kind.
 These form of dosage taken by oral route with a drought of water.
 Generally, these form of dosage found in dry state, Such as tablets,
capsules, pills are most convenient dosage form ever.
 Some solids are dispensed in bulk powder meant for external use like
dusting powders, insufflations , snuffs and tooth powders, etc.
 But if bulk powder use for internally, that time it dispensed either
granules or fine powder.
 This dosage form is easy to transfer without being leakage as may
happened with liquid form.
 People can easily administered without taking help by skilled person.

4. POWDER
Definition:
 Powder is a solid dosage form of a mixture of finely divided drug or
chemicals in dry form, are taken by either internally or externally.
 The powders are found in two form such as crystalline and
amorphous.
 The good physical, chemical and biological properties of dosage form
are totally depend on that what kind of particle size of powder we are
using.
 Particle size influencing the rate of dissolution, absorption and
therapeutic efficacy of drugs.

5.  Advantages of powders:
 Powder is an oldest dosage form and used by externally or internally.
 Powder has more stable form of dosage form than liquid one.
 It is easy for doctor to prescribe specific amount of powder to patient.
 For powder chances of incompatibility is lesser than liquid form.
 Powders give rapid onset of action than any other form of medicines
such as tablets , capsules or pills, etc.
 Large quantity of powder can easily taken by patient. By dissolving in
suitable liquid.
 Tablets or capsules are not taken by children or elder patient but
powdered solution can easily taken by them.
 This kind of dosage form can easily carry out than liquid form.
 Disadvantages of powders:
 Bitter , nauseous and unpleasant taste drugs can’t dispensed in
powder form.
 Deliquescent and hygroscopic drugs can’t delivered by this form.

6.  Drugs which are not stable at atmospheric condition are not suitable
to dispense in powder form.
 The dispensing of powder is time consuming.
 Method of preparation of powder:
 During powdering, weighing or mixing some powder losses but we
cant be avoided it, so that, we need some extra powder than required.
 The dispensing balance should not be very sensitive otherwise it will
create a difficulty to weigh the quantity less than 2 grain to 10 mg.
 So, for weighing lesser amount, we need to add diluents ( lactose) in
order to weigh it properly on balance.
 At the time of dispensing crystalline substance, first separately
triturate it and mix all ingredients in ascending order of their weight to
get uniform powder.

7.  Mixing of powders:
The powder may be mixing by following method.
1. Spatulation
2. Trituration
3. Geomatric dilution
4. Sifting
5. Tumbling
1. Spatulation:
 The powder mix with the help of spatula on paper sheet or porcelain
tile.
 This method is useful in mixing :
 Small quantity of powder
 Liquefying solid substance or eutectic mixture.
 Spatulation not suitable for large quantity of powder.
Or powder containing more than one potent substance.

8. 2. Trituration:
 It help to reduce particle size and mixing of powder.
 When reduction of particle size along with mixing required that time
this method adopted.
 A glass or porcelain Mortal and pestle are generally used for
trituration and suggested that apparatus clean rapidly after use.
3. Geometric dilution:
 This mixing method used for potent drugs
Steps: In potent drug add same volume of diluents ( lactose) in mortar
and slightly mix by trituration.
A second portion of same volume of diluents add to first mixture and
triturate in mortar.
Do the same process repeatedly until all diluents is incorporated.
Eg: If 100 mg potent drug is required to mix with 900 mg
diluents=1000mg mixture.
For mixing these kind of drugs geometric dilution method used.

9. 100mg drug+100mg diluents= 200 mg mixture
200mg mixture+200mg diluents=400 mg mixture
400mg mixture+400 mg diluents=800 mg mixture
800mg mixture+ remaining diluents=1000mg mixture
4. Sifting:
 This method is not suitable for potent drugs.
 By which, the powder mixed by passing through sifter and get light
fluffy product and is generally not acceptable.
5. Tumbling:
 This method use when need to prepare large amount of powder, in
which a rotated electric motor placed, with the help of motor to
prepare a mixture.
 This method widely used in industry for large scale production of
powder.

10.  Packing of powder:
 Powder either wrapped or dispense in wide mouth container.
1. Wrapping of powder:
 White paper is use for wrapping of powder.
 Wrapping should do on clean tile or large sheet.
2. Double wrapping:
 This wrapping adopted for volatile, hygroscopic or deliquescent
substance.
 In which the waxed paper placed inside of white paper.
Sometime aluminum foil covered from externally.
 Labeling:
 Individual powder should dissolve in little water or placed on back of
tongue before swallowing.

11. CLASSIFICATION OF POWDER
 Powders are classified on following way:
1. Bulk powder for internal use
2.Bulk powder for external use
3. Simple and compound powder for internal use
4. Powder enclosed in cachets and capsules
5. Compressed powder ( tablets)

12. 1.Bulk powder for internal use:
Non-potent drugs are supplied in bulk powder form meant for internal
use , such as antacid and laxative.
When the dose accuracy is not important that time powder dispensed in
bulk form.
These kind of bulk powder supplied in wide mouth container and it
contain several dose.
2. Bulk powder for external use:
Non-potent substance also use externally in bulk powder form
This kind of powder are deliver in cardboard , glass or plastic
containers.
The dusting powder are supplied in sifter container and container should
bear a label with instruction like meant for external use.
Eg: dusting powder, insufflations, snuffs, dentifrices.

13. a. Dusting powders:
 These powder are applied externally to the skin and contain very fine
particle to avoid local irritation.
 Fine particle size obtain by passing through sieve no. 80 to enhance
their effectiveness.
 Dusting powder get easily contaminated with pathogenic microbes
thus must be sterilized by dry heat method (160 degree C for 2 hrs)
before their use.
 It is non toxic but if infants inhale it may cause pulmonary
inflammation hence proper care should take during handling.
 Dusting powder used for their antiseptic, astringent, absorbent,
antiperspirant and antipruritic action.
Type: Medicated and Surgical
Medicated: Are used for superficial skin condition.
 It is free from pathogenic microorganisms.

14. Surgical: Are used in body cavities and on major wound like burns or
umbilical cord of infants .
 It is a sterile product.
b. Snuffs:
It is a finely divided solid dosage form, are inhaled into nostrils for
antiseptic, bronchodilator and decongestion action.
It is dispensed in flat metal box with hinged lid.
c. Insufflations:
It is meant for introduction into body cavities such as nose, throat, ears
and vagina with the help of apparatus k/as insufflators.
Potent drugs dispensed in the form of insufflations. And to produce local
effect.
d. Dentifrices ( tooth powder):
These are applied with the help of tooth brush for cleansing the surface
of the teeth.

15.  It contain detergent , abrasives , flavors, etc.
 In which strong abrasive substance should not used because it damage
the tooth structure.
3. Simple and compound powder for internal use:
 In this , each single dose enclosed in paper.
 Minimum quantity of these powders should not be less than 100mg ,
so that it can be handle easily by patient.
Simple powder: Only contain one ingredient either crystalline or
amorphous form.
 In case of crystalline powder its particle size reduced , weigh and
divided into no. of dose and wrapped as individual dose.
Compound powder: Contain two or more than two ingredients , are
mixed together and divided into individual dose and packed with
powder paper.

16. 4. Powder enclosed in cachets and capsule:
 Cachets are solid unit dosage form of drug made up of rice paper and
also called as wafer capsule.
 Cachets are basically used to pack nauseous or disagreeable drugs and
found in different size to hold drug from 0.2gm to 1.5gm of powder.
 It is little hard to swallowed but are soften by dipping in water for few
second and then placed on tongue and swallowed with water.
 After swallowed cachet become disintegrate and release drugs.
Advantages:
 It can easily made up, thus no requirement of heavy machinery.
 It quickly disintegrate in stomach and give faster effect.
 A nauseous drugs can dispensed in cachet.
 Large dose can be swallowed by cachet.
Disadvantages:
 They required to soften before swallowing.

17.  They are easily damaged.
 It cant protect the drugs from light or moisture.
 Are not suitable for filling drugs by large scale machinery.
 They occupy more space than actual size of tablet or capsule.
Types:
a. Wet seal cachet: It is made up of two similar convex halves having
flat edges.
 The weighed powder placed in lower half , moisten the edges with
water and then placed first half fitted over lower half and both
halves press together in order to seal perfectly.
b. Dry seal cachet:
 As like above cachet, it has two halves but upper half slightly larger
than lower one.
 Filling process are same and finally sealed with machinery, packed
in boxes.

18.  The B.P.C include two cachet. E.g. Sodium aminosalicylate and
sodium aminosalicylate with isoniazid.
 Packing and storage of cachet:
 Packed in boxes or tin container, labeled with the instruction ‘ before
taken, it deep in water for few second and then swallowed with
draught of water’.
5. Compressed powder ( tablet):
 It is also called as tablet triturate or moulded tablet.
 Moulded tablets are flat, circular disc shape usually contain potent
drugs with suitable diluents.
Apparatus: Tablet triturate mouled
Construction:
 Made up of stainless steel having two plate upper and lower, both
plate contain same numbers of holes.
 Mouled available in several size and capacity between 30mg to
250mg. The 50 to 250 tablet triturate can prepare at a time.

19. Working:
 Drug and diluents mix properly and convert into stiff paste with the
help of 60% alcohol.
 This paste place on upper plate, filled in hole by pressing it, after that
plate place over lower plate and a little pressure provide on upper
plate.
 After all this, eject out the moulded tablets and dried in hot air oven.
 Nowadays, automatic machine is available which can prepare 2500
tablet triturate per minute.
Packaging and storage:
 Packed in air-tight container
Or in single row in narrow tube sealed with plug type closure.
 Stored in cool place

21. DISPENSING OF POWDERS
INVOLVING SPECIAL PROBLEMS
 Volatile substance
 Hygroscopic and deliquescent powder
 Eutectic mixture
 Efflorescent powder
 Liquids or explosive substance
 Potent drugs
 During dispensing these kind of substance in powder form, number of
problems arises.
 Hence, special ideas are done while dispensing such powders.

22. 1. Volatile substance:
 Various kind of vegetable drugs contain volatile oil, hence it become
critical to dispense in powder form due to loss of volatile oil.
 So these vegetable drugs must be powdered slightly in mortar.
 These kind of problem we can prevented or at least minimize by use
of double wrapping.
 Inner wrapper should be of wax paper and outer wrapper may thick
paper.
Eg: menthol, camphor
2. Hygroscopic or deliquescent powder:
 The substance absorb moisture from atmosphere k/as hygroscopic.
 The substance absorb moisture from atmosphere and convert into
solution k/as deliquescent.
 Hence, these kind of powder dispense in granular form.
 Such powder should double wrapped or aluminum foil or plastic
cover used

23. Eg: ammonium chloride, iron and ammonium citrate
3. Efflorescent powder:
 Some crystalline substance liberate water on expose to humid
atmosphere or during trituration and thus become wet or liquefy.
 This problem may overcome by adding anhydrous salt or inert
substance with efflorescent powder before adding with other
ingredients.
Eg: caffeine, citric acid, ferrous sulphate
4. Eutectic mixture:
 It is a result of mixing of two or more substance together and form a
soft mass of low melting point than room temperature.
 To overcome these, add equal amount of absorbent ( mg. carbonate,
starch, lactose) in eutectic mixture and blended together lightly with
spatula.
Eg: thymol, phenol, aspirin, chloral hydrate

24. 6. Liquids:
 In some prescription liquid medicament added in dispensing powder.
 Small qty of liquid: it triturate with equal volume of powder, then
remaining portion added to it with continuous trituration,
 Large qty of liquid: along with above, add some adsorbent.
Examples of liquid: liquid extract and tinctures.
7. Explosives substance:
 When oxidizing (Pot. Chloride)and reducing substance (tannic acid)
mixed together, chances of happening explosion.
 To overcome these: powder each ingredient separately and dispensed
in separate paper with suitable direction.
8. Potent drugs:
 Substance having maximum dose is less than 60mg or poisonous
substance are called as potent drugs.
 To overcome these: potent drugs mixed with some diluents in mortar
with light trituration.

25. 9. Granular powders:
 If bitter, nauseous and unpleasant taste substance need to dispense in
large dose, that time it not possible to dispense as tablet or capsule
form or liquid form due to stability problem.
 Hence, these kind of powder dispensed in granular form.
10. Effervescent granules:
 It is a special preparation of solid dosage form of medicament ( bitter
or saline taste)
 Drugs mixed with citric acid or tartaric acid and Na.Bicarboante also
some sweetening agent.
 Before taken , desire quantity of granules dissolve in water.
 The acid and Na2HCO3 react and form effervesces ( CO2 release), it
mask the unpleasant taste along with this CO2 increase gastric flow
and help for good absorption of drugs.

26.  Method of preparation:
 There are two method for preparation of effervescent granules.
Heat method
Wet method
1. Heat method:
 Take large porcelain evaporating dish and placed over boiling water
bath.
 Transfer a powder into hot dish and to ensure liberation of water from
citric acid, if heat will not release, provide slow heating until
coherent mass obtain.
 After that dump mass passes through sieve to prepare granules of
desire size, dried on oven up to 60o C and packed in air tight
container.
2. Wet method:
 In all ingredients mix with alcohol and make coherent mass, pass
through sieve no. 8 and dried on oven up to 60o C.

27.  These granules again passed through given sieve to break lump, the
dried granules packed in air tight container.

28. WEIGHING TECHNIQUES

29.  Weighing is one of the most important operation of manufacturing all
kind of pharmaceutical products.
 And the growth of company depend on a proper weighing, which is
possible only if there is thorough knowledge of balance, its principle,
its care and its proper use.
 Following techniques should be followed while weighing the
material:
 Keep the balance in clean place for use.
 Adjust the level of balance and clean balance and pan with dry duster.
 Place the white paper below the each pan to prevent corrosion.
 By using forceps. place the required weight on left hand pan.
 Remove the required ingredients bottle and check its name.
 Add or remove ingredients to the right hand pan with the help of
spatula until desired quantity obtain.
 Transfer the weighed material in container or on piece of paper as per
requirement.

30.  Return the bottles to the shelf after taking it.
 Return the weight to drawer with forceps and carefully clean the pan
and spatula.
 Possible error in weighing:
During weighing there can be chances of occurring some errors due to
following reason:
1. Improperly leveled of balance.
2. If rest point of balance is not correct.
3. Due to unequal weight of two pan.
4. If rough surface of the pan.
5. If weights are handle with hand, not with forceps.
6. If material is weighing during oscillating pans.

31.  Minimum weighable amount:
 Now it is accepted fact that error in the amount of any ingredients in
dispensing preparation should not be less than +/- 5%
Eg: If substance to be supplied as 100mg it must not be less than 95mg
and not more than 105mg.
 Electronic balance:
 Nowadays, mechanical balance replaced by electronic balances.
 Electronic balance able to weigh very small quantities of potent drugs.
 A various types of electronic balance are available in market with
different degree of sensitivity.

32. REFERENCE
R. M. Mehta, pharmaceutics-II, second adition-2003,reprint
2010,vallabh prakashan. Pg. No. 75 to 96