UNIT 2 SOLID AND LIQUID DOSAGE
FORMS
Solid and Liquid
Dosage Forms
Structure
2.1
Introduction
Objectives
2.2
Solid Dosage Forms
Tablets
Capsules
2.3
Liquid Dosage Forms
Advantages of Liquid Dosage Forms
Disadvantages of Liquid Dosage Forms
Classification of Liquid Dosage Forms
Monophasic Liquid Dosage Forms
Biphasic Liquid Dosage Forms
2.4
2.5
2.6
Summary
Terminal Questions
Answers
2.1
INTRODUCTION
The previous chapter has given an idea about the different kinds of dosage
forms available and also about its packing. The present chapter gives an
account of the solid dosage forms and various liquid dosage forms.
Crude extracts and powdered drugs can be administered as such for treating
diseases. But this has got many disadvantages like susceptible to microbial
attack, poor solubility and poor acceptability by the patient due to unpleasant
taste and odour.
So it is necessary to design dosage forms that are convenient and acceptable for
administering drug to patient. Let us first study about solid dosage form.
Objectives
After studying this unit, you should be able to:
•
•
•
•
•
discuss solid dosage form;
explain advantages and disadvantages of solid dosage form;
discuss liquid dosage form;
explain advantages and disadvantage of liquid dosage form; and
classify liquid dosage form.
25
Pharmaceutics
2.2
SOLID DOSAGE FORMS
The solid dosage forms commonly used in olden days, are cachets, pills,
moulded tablets, etc.
Cachets are wafers made up of rice flour; powders are enclosed in these wafers
and sealed so that their taste can be masked. These are less widely used due to
some disadvantages like difficulty in swallowing.
Moulded tablets are powders moulded into tablets. These are cylindrical or
circular disc shaped. Usually drugs that require only fewer doses are made into
this form. These are also seen very rarely nowadays.
Pills are widely used before the introduction of the tablets. The medicament
mass is rolled into pipe of uniform thickness and it is cut into suitable sizes.
Then it is rounded by using a pill rounder, usually it is spherical or ovoid in
shape.
Later by the introduction of tablets and capsules all the above forms are largely
replaced by them.
Fig.2.1: Solid dosage form
2.2.1 Tablets
26
Tablets are solid dosage form in which one usual dose of the drug has been
accurately placed (Fig. 2.2). They are the most popular form of medication.
They come in different sizes and shapes. Size varies from a few mm to a cm. It
depends upon the quantity of medicament. Medicines in tablet have some
advantages and some disadvantages. Let us discuss them separately.
Solid and Liquid
Dosage Forms
Fig.2.2: Tablets
Advantages
Tablets have following advantages:
i) It is easy to administer a correct dose. Here there is no need of any
measurement of the dose. The dose is accurately placed in a rigid compact
form.
ii) Their cost is lowest of all oral dosage forms. The price for the tablet is low
when compared to other dosage forms.
iii) It is a stable dosage form. The tablets are very stable to various physical
conditions.
iv) It is convenient to carry. The tablets can be packed in convenient and user
friendly light weight and easy to carry packages. .
v) It is easy to swallow. It is easy to swallow with a draught of water.
Disadvantages
Tablets have some disadvantages also i.e.
i) Some powders cannot be compressed into tablets.
ii) Geriatric and paediatric patients find difficulty in swallowing tablets.
Types of tablets
There are different types of tablets. Some of them are given below:
a) Tablets that disintegrate readily when swallowed, these tablets have rapid
absorption. These tablets do not have any coating. They are uncoated
tablets.
b) Lozenge tablets: Lozenges are solid dosage form that do not disintegrate
readily and are intended to dissolve slowly in the mouth. They produce a
local action on the throat.
27
Pharmaceutics
c) Solution tablet: These tablets have to be dissolved in water for
administration. It can be used either externally or by injection.
d) Chewable tablet: These tablets are chewable in the mouth and are not
intended to be swallowed.
e) Buccal tablets: These are placed in the buccal pouch. Here they dissolve or
disintegrate slowly and is absorbed directly without passing into alimentary
canal.
f) Sublingual tablet: These are placed under the tongue. Here they dissolve
or disintegrate slowly and is absorbed directly without passing into the
alimentary canal.
g) Implants: These tablets are placed under the skin by means of a minor
surgical operation and are slowly absorbed.
Coated Tablets
Some medicaments that are compressed into tablets are coated with sugar or a
film made from a suitable polymer. Accordingly they are called sugar coated
and film coated tablets. The coating is done because of:
•
•
•
To provide physical and chemical protection to the drug
To improve the appearance
To mask the unpleasant taste / colour / colouration of the drug
Method of Preparation
The medicament is compressed along with some additives. Additives or
excipients are added for easy compression. The additives used are
a) Diluents: These are added to increase the bulk of the medicament for easy
compression e.g. lactose.
b) Lubricants: They are added to increase the flow property of the powder
e.g. talc.
c) Glidants: They are added to increase the flow property of the powder e.g.
talc.
d) Disintegrants: These are added to disintegrate the tablet into small parts
e.g. starch.
e) Colouring agents: They give colour which improves the appearance of the
product e.g. amaranth.
f) Flavorings agents: They are added to impart flavour e.g. mint.
g) Sweetening agents: They give sweetness to the product e.g. sucrose.
The compression of the powder into tablet is carried out by tablet making
machine. Hand operated tablet machines and rotary tablet machines for large
scale manufacturing are available.
28
Packaging of Tablets
In the olden days tablets are packed in amber coloured glass bottle, jar or vial.
It is inconvenient to carry as it is bulky. This is very susceptible to crushing
while transportation and hence adequate protection was required. Later packing
in a single row in a narrow tube sealed with a plug type plastic closure was
employed. Modern method of tablet packing includes strip or blister packs.
Solid and Liquid
Dosage Forms
Fig.2.3: Strip packing
i) Strip pack: The tablets are hermetically sealed within strips of aluminium
or plastic foil (Fig. 2.3). The tablet can be removed from this pack by
tearing or cutting. This method is attractive, hygienic and is suitable for
large scale production.
Fig.2.4: Blister packing
ii) Blister pack: The film enclosing the tablet is formed into a blister. The
tablet can be removed by pressing on the blister and force the tablet
through the backing strip. This is also attractive, hygienic and suitable for
large scale production.
On completion of this section you would come to know about the following
aspects.
SAQ 1
Fill in the blanks:
a) Tablet triturates are prepared by moulding powder into ____________.
b) The compression of powder into tablet is carried out by ____________.
c) ______________ tablets are placed in the buccal pouch.
d) ____ are placed under the skin by means of a minor surgical procedure.
29
Pharmaceutics
SAQ 2
What are the solid dosage forms commonly used in the olden days before the
introduction of tablets?
……………………………………………………………………………………
……………………………………………………………………………………
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SAQ 3
What are the different types of tablets?
……………………………………………………………………………………
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2.2.2
Capsules
Capsules are solid dosage form in which the drug substance is enclosed in
water soluble shell or an envelope (Fig.2.5). They are in water soluble shell
because it can dissolve. Capsule shell is made up of gelatin. Gelatin is a protein
obtained from animal collagen. The capsules are available in eight sizes. The
size is designated as numbers from 000 (largest) to 5 (smallest) and capsule
capacities vary accordingly i.e.
Fig.2.5: Capsules
30
Capsule No:
000
00
0
1
2
3
4
5
Content mg:
950
650
450
300
250
200
150
100
Solid and Liquid
Dosage Forms
Fig.2.6: Capsule sizes
On the basis of their shell capsules are classified as i) hard gelatine capsule and
ii) soft gelatin capsules.
Advantages
i)
They mask the taste and odour of unpleasant drug.
ii) They are attractive in appearance.
iii) They are slippery when moist, hence easy to swallow.
iv) Less additives are necessary for the preparation when compared to tablet.
v) It provides rapid and uniform release of medicament in the gastro
intestinal tract.
vi) The shell can be coloured to give protection from light.
vii) They protect the medicament from air and moisture due to very fine limits
of the shell.
viii) The capsule shell is physiologically inert, easily and quickly digested in
the gastro intestinal tract
Disadvantages
i) The drugs that absorb moisture cannot be filled in the capsule.
ii) It is expensive.
There are two types of capsules: hard and soft gelatin capsules.
Hard Gelatin Capsules
The capsule shell of hard gelatin capsule consists of two parts, a body and a
cap. They are cylindrical in shape (Fig. 2.7). The medicament of these capsules
is in the form of powder or granules. These capsules are sealed after filling.
Fig.2.7: Hard gelatin capsules
31
Pharmaceutics
Soft Gelatin Capsules
These capsules shell is a single unit. They are round, oval, pear or tube shaped
(Fig. 2.8). The medicament of these capsules is in the form of liquid or paste.
The soft gelatin capsules are round, oval, pear or tube shaped. Unlike hard
gelatin capsules, their shell is a single unit. The soft gelatin capsules are most
suitable for liquids semi-liquids and also for vitamins and multivitamins.
Liquid medicines with unpleasant taste and odour can be conveniently
administered in soft capsules. Ointments that are used in the eye are frequently
packed in unit dose tube shaped soft capsules. The filling and sealing of
capsules are combined operation.
Fig.2.8: Soft gelatin capsules
Manufacturing of capsules
The capsules can be filled either by hand or by a semi-automatic device or by
automatic filling machine. A rotary capsule filling machine is used for large
scale preparation of soft gelatin capsules.
SAQ 4
Fill in the blanks:
a) A capsule shell is made from ____________.
b) The shell can be ____________ to give protection from light.
c) The contents of hard gelatin capsules are in the form of ______________.
SAQ 5
What are the advantages of capsule?
……………………………………………………………………………………
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……………………………………………………………………………………
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32
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2.3
LIQUID DOSAGE FORMS
Solid and Liquid
Dosage Forms
Liquid dosage forms are either monophasic or biphasic. A monophasic liquid
dosage form is one which contains only one phase. That is, it is a true solution
(Fig. 2.9). A true solution is a homogenous mixture of solid, liquid or gas in a
liquid. A biphasic liquid dosage form contains two phases.
Fig.2.9: Liquid dosage forms
2.3.1 Advantages of Liquid Dosage Forms
i) They are the most suitable dosage form for infants, children and geriatric
patients.
ii) The unpleasant taste of the drugs can be masked by adding sweetening and
flavouring agents.
iii) It is attractive in appearance and gives beneficial psychological effects.
iv) The drug is rapidly available for absorption.
2.3.2 Disadvantages of Liquid Dosage Forms
i) The liquid dosage forms have less stability when compared to solid dosage
forms.
ii) It is bulky to carry.
iii) A spoon is needed to administer a dose.
iv) Accidental breakage of the container results in loss of whole dosage form.
2.3.3 Classification of Liquid Dosage Forms
Liquid dosage forms are broadly classified into two groups:
a) Monophasic liquid dosage forms
b) Biphasic liquid dosage forms
33
Pharmaceutics
2.3.4 Monophasic Liquid Dosage Forms
It is the simplest form of presenting medication for rapid absorption of the
drug. It is a one phase system consisting of two components, solute and the
solvent. The component that get dissolved is called a solute and the medium in
which solute dissolves is called a solvent. The monophasic liquid dosage form
are broadly classified into four groups. Each one can be further classified into
different groups as shown below:
Monophasic Liquid Dosage Forms
Oral use
Mixtures
Elixirs
Syrups
Linctuses
Draughts
Drops
External use
Lotions
Liniments
Collodions
Special use
Parenteral Use
Gargles
Mouth washes
Throat paints
Nasal drops & sprays
Douches
Enemas
Eye drops
Eye lotions
Ear drops
Inhalations
Aerosols
A. Oral Used Preparations
There are six different types of orally used preparations i.e. mixtures,
elixirs, syrups, linctuses, draughts and drops. Let us studies them
separately.
i) Mixtures
A mixture is a liquid preparation meant for oral administration in which
a medicament or medicaments are dissolved or suspended in a suitable
liquid. They should be freshly or recently prepared and used fairly
quickly, usually within a month. They are mainly prescribed for short
term therapy like cough, diarrhoea, constipation etc. Mixtures are
further classified into five different groups i.e.
a) Simple mixtures containing soluble substances: It contains only
soluble ingredients.
34
b) Mixtures containing diffusible solids: Diffusible solids are those
which do not dissolve in water, but may be mixed by shaking. As a
result it is evenly distributed throughout the liquid for sufficient
time.
c) Mixtures containing indiffusible solids: Indiffusible solids are
those which are not soluble in water and do not remain uniformly
distributed in the solvent for sufficiently long time. So we have to
add a substance to suspend (suspending agent) these particles in the
solvent.
Solid and Liquid
Dosage Forms
d) Mixtures containing precipitate forming liquids: Some mixture
contains liquids that get precipitate when mixed with water. This
precipitate will stick to the sides of the bottle and is difficult to
distribute uniformly. So we have to add a suspending agent.
e) Mixtures containing slightly soluble liquids: Some liquids
contains insoluble portion which is not distributed uniformly. Here
also we have to add a suspending agent.
ii) Elixirs
Elixirs are clear, flavoured, sweetened, hydroalcoholic preparations for
oral administration. They are more stable than mixtures. Elixirs are
classified into two classes.
a) Non medicated elixirs: These elixirs do not contain any
medicament but contain some aromatic or pleasantly flavoured
substances. These are used as solvents for other liquid preparations.
b) Medicated elixirs: These elixirs contain some medicinal substance
along with other ingredients.
iii) Syrups
Syrups are liquid oral preparations in which the vehicle is a
concentrated solution of sucrose or other sugars in water. The
concentration of sugar in syrup is 66.7 % W/W. Syrups are further
classified into 2 classes.
a) Simple syrups: The simple syrups do not contain any medicament,
but contains some pleasantly flavoured substances. These syrups are
used as a medium for other liquid preparations.
b) Medicated syrups: These syrups contain some medicinal substance
along with other ingredients.
Advantages of syrups
•
•
Syrups prevent oxidation and decomposition of drugs.
Syrups are sweet in taste and therefore bitter taste of drugs can be
reduced.
Disadvantages of syrups
•
•
Syrups are not preferred for diabetic patients.
On continuous take syrup promote dental decay.
35
Pharmaceutics
iv) Linctuses
Linctuses are defined as viscous oral liquids containing one or more
medicament dissolved in a vehicle that usually contains high proportion
of sucrose or other sugars. They are used in the treatment or relief of
cough. It must be sipped slowly in small doses. This gives maximum
and prolonged effect of medicament in the throat. The usual dose is
5ml.
v) Draughts
Draughts are liquid oral preparations, which contain only one or two
large doses. Each dose is supplied in separate bottle.
vi) Drops
Drops are liquid preparations meant for paediatrics. Generally vitamins
and antibiotics are given in the form of draughts. It must be supplied
along with a dropper.
B. Externally Used Preparations
They are of three types:
i) Lotion
Lotions are fluid preparations for external applications. They are rubbed
on the skin without friction. It has a cooling, soothing and protective
action.
ii) Liniments
Liniments are viscous liquid preparations for external application. It is
applied to the unbroken skin with friction and rubbing. Liniments
should never be applied to broken skin because they cause irritation.
They are used for relieving pain.
iii) Collodions
Collodions are fluid preparations for external use. They are applied
with a brush or rod. After applying on the skin the vehicle evaporates
and leaves a protective film covering the site. They are of two types.
a) Un-medicated: It contains no medicament and is used for
protecting small cuts and wounds.
b) Medicated: It contains medicament.
C. Specially Used Preparation
There are 11 different types of specially used preparation which are
discussed below:
i) Gargles
36
They are aqueous solution used to prevent or treat throat infections.
ii) Mouth wash
These are preparations used to cleanse and deodorize the buccal cavity.
They are very refreshing to bed-ridden patients.
Solid and Liquid
Dosage Forms
iii) Throat paints
Throat paints are viscous liquid preparations used for mouth and throat
infections. They are applied with the help of a brush. Nasal drops and
sprays.
iv) Nasal drops and sprays
Nasal drops are solutions of drugs that are instilled into the nostrils with
the help of a dropper. Nasal sprays are the same preparations as nasal
drops but instilled into the nostrils in the form of a spray.
v) Douches
Douches are aqueous solutions used to cleanse deodorize, soothe or
medicate wounds, body orifices or cavities.
vi) Enemas
Enemas are preparations intended for introducing in the rectum for
cleansing therapeutic or diagnostic purposes. It is used to evacuate
faeces in constipation or before an operation.
vii) Eye drops
Eye drops are sterile preparations for instilling into the eye.
supplied with a dropper.
It is
viii)Eye lotions
Eye lotions are sterile aqueous solutions used for washing the eye. It is
generally used to remove foreign substances from the eye.
ix) Ear drops
They are medicated solutions to be instilled into the eye with the help
of a dropper. It is used for cleaning and for treating the infections.
x) Inhalations
They are preparations containing volatile substances. They are used to
relieve congestion and inflammation of the respiratory tract. They are
added to hot water and the vapours are inhaled.
xi) Aerosols
Aerosols are liquid preparations dissolved in a solvent. The solvent is a
gas. It is delivered in the form of a spray. It is mainly used for treating
asthma and also for migraine.
37
Pharmaceutics
D. Parenteral Solutions (Injections)
Parenteral solutions are sterile drug solutions intended for administration
by injections. Injections can be intravenous, intra muscular; intra dermal
etc., skilled persons are required for the administration of injections.
2.3.5 Biphasic Liquid Dosage Forms
Biphasic liquid dosage form is one which contain two phases i.e. emulsions
and suspensions.
Biphasic Liquid Dosage Forms
Suspensions
Emulsions
A. Suspensions
Suspensions are biphasic liquid dosage forms in which finely divided solid
particles are dispersed in a liquid. It consists of two phases, a disperse phase
and continuous phase.
The solid particles act as disperse phase whereas liquid acts as a continuous
phase. The medicaments that are insoluble or poorly soluble are formulated as
suspensions. Suspensions contain a suspending agent. A suspending agent is a
substance that is added to the preparation to suspend the insoluble particles in
the preparation. It can be classified into four groups.
a) Oral suspensions: These suspensions are to be consumed by oral route.
b) Parenteral suspensions: The suspensions which are administered by
parenteral route are called parenteral suspensions.
c) Ophthalmic suspensions: These are used for instilling into the eye.
d) Suspensions for external use: These are used for external applications.
Packing of Suspensions
Suspensions can be packed in narrow mouth screw caped colour less plain
bottle. Suspensions that are very thick require a container with wide mouth.
Suspensions should be stored in a cool place.
B. Emulsions
An emulsion is a biphasic liquid preparation containing two immiscible liquids
one of which is dispersed as minute globules into the other. When two
immiscible liquids are in contact there exists a separating surface. Vigorous
shaking is necessary to break one liquid into small globules in the other. But
this condition is only temporary and separate quickly on standing. Example is
the mixture of oil and water. So we can add a third substance to distribute one
liquid in the other with out the formation of a separate layer. This substance is
38
called an emulsifying agent and the product is called an emulsion. There are
two types of emulsion.
Solid and Liquid
Dosage Forms
Medicines having an unpleasant taste and order can be made more palatable for
oral administration in the form of an emulsion. Emulsions protect drugs against
oxidation or hydrolysis.
•
•
Emulsions are less stable.
They are susceptible to microbial growth.
Packing of Emulsions
Emulsions can be packed in narrow mouth screw caped colourless plain bottle.
Emulsions that are very thick require a container with wide mouth. Emulsions
should be stored in a cool place.
a) Oil in water type: This type of emulsion is the one in which the oil is
dispersed in the water
b) Water in oil type: This type of emulsion is the one in which the water is
dispersed in the oil. Emulsions may be liquid or semi-solid.
Liquid emulsions can be classified as
i)
ii)
iii)
iv)
emulsions for oral administration,
emulsion for external uses,
emulsion for parenteral uses, and
emulsion for rectal use.
i) Emulsions for oral administration
Some medicaments are unpleasant in taste. For example fish liver oil, we
can mask this unpleasant taste by converting it into an emulsion and can be
given orally.
ii) Emulsions for external use
The external preparation of emulsion consists of three classes.
Applications, lotions and liniments, these emulsions can be either oil in
water or water in oil.
iii) Emulsions for parenteral use
Some patients are unable to ingest food in the normal way. We can
administer oil in water emulsions of nutritive oils and fats to these patients.
Vitamin K that prevents blood clotting is injected in this form.
iv) Emulsions for rectal use
Some emulsions are given by rectal route. Semi-solid emulsions are water
in oil or oil in water type. The water in oil type semi-solid emulsions are
oily creams while the oil in water semi-solid emulsions are aqueous
creams. Creams are easy to apply and are less greasy.
39
Pharmaceutics
SAQ 6
Fill in the blanks:
a) Liquid dosage form is most suitable for ____________ & __________.
b) Drug is ____________________ absorbed by liquid dosage forms.
c) Monophasic systems mean, systems containing only one ___________.
d) Syrups are concentrated solutions of _______________ and other sugars in
water.
e) Elixirs are clear,
preparations.
flavoured,
sweetened
______________
liquid
f) Drops are liquid dosage forms meant for ______________________.
g) Linctuses are used in the treatment or relief of ___________________.
h) Gargles are used for ______________ & ________________ infections.
i) _______________ are refreshing to bed ridden patient.
j) _______________ & sterile aqueous solutions for instillation into the eye.
k) ________________ are sterile aqueous solutions used for irrigation or
washing the eye.
l) Parental preparations are given in the form of ___________________.
SAQ 7
Write advantages of liquid dosage form?
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2.4
SUMMARY
In this unit we have discussed the following points in details.
40
•
The solid dosage forms commonly used in olden days, are cachets, pills,
moulded tablets, etc.
•
Moulded tablets are powders moulded into tablets
•
Tablets are solid dosage form in which one usual dose of the drug has been
accurately placed
•
There are different types of tablets like Lozenge tablets, Solution tablet,
Chewable tablet, Buccal tablets, Sublingual tablet and Implants
•
The medicament is compressed along with some additives. Additives or
excipients are added for easy compression
•
Modern method of tablet packing includes strip or blister packs.
•
Capsules are solid dosage form in which the drug substance is enclosed in
water soluble shell or an envelope
•
On the basis of their shell capsules are classified as i) hard gelatine capsule
and ii) soft gelatine capsules
•
Liquid dosage forms are either monophasic or biphasic. A monophasic
liquid dosage form is one which contains only one phase
•
Liquid dosage forms are broadly classified into two groups (i) Monophasic
liquid dosage forms, (ii) Biphasic liquid dosage forms
•
Monophasic Liquid dosage forms can be classified in to different four
groups, i.e., Oral used preparation, External used preparation, Special used
preparation and Parenteral used preparation
•
Biphasic Liquid Dosage Forms can be classified into two different groups,
i.e. Suspensions and Emulsions
2.5
Solid and Liquid
Dosage Forms
TERMINAL QUESTIONS
1. What are the disadvantages of tablets?
2. Differentiate hard and soft gelatin capsule?
3. Distinguish lotion and liniment.
4. What are draughts?
5. What is Suspension?
6. What are the classifications of emulsion?
7. Match the Following:
i) Lotion
:
a) Concentrated solution of sucrose in water
ii) Parenteral
:
b) Apply without friction
iii) Syrups
:
c) Less stable
iv) Mixtures
:
d) Administer in the form of injection
41
Pharmaceutics
2.8
ANSWERS
Self Assessment Questions
1. a)
b)
c)
d)
Tablets
Tablet making machine.
Buccal
Implants
2. The solid dosage forms commonly used in olden days, are cachets, pills,
moulded tablets, etc. (Refer section 2.2.)
3. There are different types of tablets like Lozenge tablets, Solution tablet,
Chewable tablet, Buccal tablets, Sublingual tablet and Implants
4. a) Gelatine
b) Coloured
c) Powder
5. Main advantages of the capsule are:
i)
They mask the taste and odour of unpleasant drug.
ii) They are attractive in appearance.
iii) They are slippery when moist, hence easy to swallow.
iv) Less additives are necessary for the preparation when compared to
tablet.
v)
It provides rapid and uniform release of medicament in the gastro
intestinal tract.
vi) The shell can be coloured to give protection from light.
vii) They protect the medicament from air and moisture due to very fine
limits of the shell.
viii) The capsule shell is physiologically inert, easily and quickly digested
in the gastro intestinal tract,
6. a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
42
Paediatrics & Geriatrics
Rapidly
Phase
Sucrose
Hydroalcoholic
Paediatrics
Cough
Mouth & Throat
Mouthwashes
Eyedrops
k) Eye lotions
l) Injectons
Solid and Liquid
Dosage Forms
7. Main advantages of the liquid dosage forms are:
i) They are the most suitable dosage form for infants, children and
geriatric patients.
i) The unpleasant taste of the drugs can be masked by adding sweetening
and flavouring agents.
ii) It is attractive in appearance and gives beneficial psychological effects.
iii) The drug is rapidly available for absorption.
Terminal Questions
1. Tablets have some disadvantages also i.e.
i) Some powders cannot be compressed into tablets.
ii) Geriatric and paediatric patients find difficulty in swallowing tablets.
2. Hard gelatin capsule shell is consists of two parts, a body and a cap. They
are cylindrical in shape. The medicament of these capsules is in the form of
powder or granules. Soft gelatin capsules shell is a single unit. They are
round, oval, pear or tube shaped. The medicament of these capsules is in
the form of liquid or paste.
3. Lotions are fluid preparations for external applications. They are rubbed on
the skin without friction. It has a cooling, soothing and protective action.
Liniments are viscous liquid preparations for external application. It is
applied to the unbroken skin with friction and rubbing.
4. Draughts are liquid oral preparations, which contain only one or two large
doses. Each dose is supplied in separate bottle.
5. Suspensions are biphasic liquid dosage forms in which finely divided solid
particles are dispersed in a liquid. It consists of two phases, a disperse
phase and continuous phase.
6. Liquid emulsions can be classified as
i)
ii)
iii)
iv)
emulsions for oral administration,
emulsion for external uses,
emulsion for parenteral uses, and
emulsion for rectal use.
7. Match the following:
i)
ii)
iii)
iv)
(b)
(d)
(a)
(c)
43