Introduction to dosage forms

INTRODUCTION TO DIFFERENT
DOSAGE FORMS
Ronald Peter
Assistant Professor
Dept. of Pharmaceutics

Drug:
A drug is defined as an agent, used or intended for use in the diagnosis, mitigation,
treatment, cure or prevention of disease in man or in other animals.
Drugs are rarely administered in their pure state. They are combined with other
ingredients to formulate them into a dosage form (suitable formulation).
Dosage forms:
Dosage forms are pharmaceutical drug products in the form, in which they are
marketed for use.
Every dosage form is a combination of drug/drugs and other non-drug components
called additives / excipients.
They are used to give, particular shape / increase the stability / increase
palatability / to give more elegance to the dosage form.
Lisie College of Pharmacy, Kochi

Classification;
Based on - Physical nature
Solid
Semi solid
Liquid
Gaseous
Route of administration
Oral
Parentral
Topical
Rectal
Inhaled
Site of Application
Skin
Nose
Eye
Ear
Use
Externally
internally

GASEOUS
DOSAGE FORM
Inhalers
Aerosols

Importance of Dosage Forms
Formulation of drugs into diff. Dosage forms is done for following reasons;
1. Protect the drug from oxidation, hydrolysis and reduction.
e.g. coated tablets.
2. Protect the drug from destructive effect of gastric juice after oral administration
e.g. enteric coated tablets
3. Provide safe and convenient delivery of accurate dose.
e.g. tablets
4. Conceal the bitter, salty or noxious taste/odour of the drug.
e.g. capsules, flavoured syrup
5. To provide optimum action through inhalation
e.g. inhalation aerosols
6. Provide for insertion of drug into body cavity
e.g. suppositories, ear cones

7. For maximum drug action from topical administration sites
e.g. creams, ointments etc.
8. Provide sustained release action.
e.g. Sustained release tablets.
9. Provide liquid dosage form of drugs soluble in suitable vehicle.
e.g. Solution
10. Provide liquid dosage form of drugs insoluble or unstable in a vehicle.
e.g. Suspension
11. Provide drugs into the body tissues.
e.g. Injections
12. To identify between different dosage forms by colour, shape or any such markings.

Classification of dosage forms
Dosage forms may be classified on the basis of their physical form of the final
product. They are;
o Solid dosage forms
o Liquid dosage forms
o Semi-solid dosage forms
o Gaseous dosage forms
New drug
delivery
system

Solid dosage form
Solid dosage forms are available mostly in unit dosage forms such as tablets,
capsules, pills, cachets or powders.
But some solid dosage forms are packed and supplied in bulk. They may be
granules or fine powders and Effervescent granules, meant for internal use.
Dusting powder, insufflations, snuffs and tooth powder, for external use.
Advantages of unit dosage forms;
1. Most convenient form, if it is to administered in orally.
2. They are effective and patient will not be having any problem in handling,
identification and administration.

SOLID DOSAGE FORMS
 POWDERS
 GRANULES
 TABLETS
 CAPSULES
 PILLS

1. Powders
Powders are solid dosage forms of medicament, which are meant for internal or
external use in its fine state. They are available in crystalline or amorphous form.
Powders are generally classified into;
 Bulk powder for internal use
e.g. Fine powder / granules
 Bulk powder for external use
e.g. Snuffs, dusting powder, tooth powder
 Simple and compound powder for internal use
e.g. Aspirin powder, APC powder
 Powder in the form of compressed tablets – tablet triturates
 Powders enclosed in cachets and capsules

POWDERS
 Dusting powder
 Insufflations
 Snuffs
 Dentifrices

Dusting powder
o These are meant for external application to skin and are generally applied in very
fine state, to avoid local irritation. Hence dusting powder are passed through sieve
no.80. it also enhances its effectiveness.
o Dusting powders are of two types;
 Medical
 Surgical
o Dusting powders are mainly used for;
 Antiseptic – an agent that prevents the growth of any pathogenic microorganisms.
 Astringent – an agent that helps in protein precipitation
 Absorbent – an agent that absorbs any matter into it.
 Antiperspirant – an agent that prevents/reduces sweating.
 Antipruritic actions – an agent that relives itching.

 Medical dusting powder and Surgical dusting powder
 Medical dusting powder are mainly used for superficial skin conditions
 Surgical dusting powder are used in body cavities, major wounds, umbilical cords
etc.
 Medical dusting powders need not be sterile but should be free from dangerous
pathogenic organisms.
 Surgical dusting powders must be sterilized before use.
Sl. No. Medical Dusting Powder Surgical Dusting Powder
1
Used mainly for superficial
skin conditions
Used in body cavities and
major wounds, umbilical
cord of infants
2
Must be free of pathogenic
microorganisms
Must be sterilized

 Formulation
 Dusting powders are generally prepared by mixing 2 or more ingredients, one of
which will be either starch, kaolin or talc.
 Of the above ingredients, talc and kaolin are commonly used as they are
chemically inert.
 However, these ingredients are readily contaminated with pathogenic bacteria,
they must be sterilized before use.
 Containers
• Generally dispensed in sifter-top containers/aerosol containers.
• Also dispensed in flat circular containers
 Precaution
• Relatively non-toxic, but may cause pulmonary inflammation if inhaled due to its
fine state. So proper care must be taken while handling.

Insufflations
 These are medicated dusting powders meant for introduction into body cavities
such as nose, throat, ear and vagina.
 Insufflations should be in finely divided state, as it has to be sprayed to the site of
application.
 Applied with the help of an apparatus known as insufflators.
• Difficulties
 Difficult to obtain accurate measured qty as uniform dose.
 May get blocked when powder used or apparatus is slightly wet.

• Now a days – insufflations are available in the form of pressure aerosols.
• It helps in excellent control of dose through metered valves.
• So that they can be used for administering potent drug
• It also helps to protect the powder form external environment.
 Use
– To produce local effects, as in treatment of ear, nose and throat infections
– To produce systemic effect of a drug that may be destroyed in the gut

Snuffs
• These are finely divided solid dosage form (powder) which are meant for inhalation
into nostrils.
• They are dispensed in flat metal boxes with or without hinged lid.
• Special Aluminium Snuff bullets are also available for administration of snuffs.
Uses
• Antiseptic, Bronchodilator and decongestion action

Dentifrices (tooth powder)
• They are agents that are used for cleaning and polishing of the teeth. They may be
in the form of powder, liquid, paste etc.
• They are applied with the help of tooth brush for cleaning the surface of teeth.
• They may contain,
• Abrasives – Precipitated Calcium Carbonate, Calcium Phosphate, Calcium sulphate,
Magnesium carbonate, Sodium carbonate and Sodium chloride.
However strong abrasives are not used, as it may damage the teeth.
• Detergent – Sodium Lauryl Sulphate, Sodium alkyl suphosuccinate
• Flavouring agent – Peppermint oil, Cinnamon oil
• therapeutic agent – Antibiotics, Fluorides
• Sweetening agent - Saccharin
• Binders – Gum tragacanth, Methyl cellulose
• Preservatives – Methyl and Propyl Paraben

Dentifrice (NF XI)
Hard soap, fine powder 50gm
Precipitated calcium carbonate 935gm
Saccharin sodium 2gm
Peppermint oil 4ml
Cinnamon oil 2ml
Methyl salicylate 8ml
 Triturate the saccharin sodium, the oils and methyl salicylate with about one half of
the precipitated calcium carbonate and mix the soap with remaining portion of
precipitated calcium carbonate. Mix them thoroughly and then pass it through a
fine sieve.

2. Granules
• Granules are aggregations of fine particles of powder to form almost spherical
mass.
• Some powders, which may be bitter, nauseous and having unpleasant taste cannot
be given in tablet form.
• They may not be able to formulate it into capsules due to heavy dose.
• Such powders may also not be able to formulate into liquid forms due to stability
problems.
• Such medicaments are given in the form of granules.
Advantages;
1. Avoids powder segregation
2. Provide high porosity than powder
3. Hygroscopic powder, may adhere and form hard cake, which can be minimised if
converted to granules.

Granules
 Simple granules
 Effervescent granules

Simple granules
• Here the drug is mixed with sugar, flavouring agent and a granulating agent to
prepare a coherent mass.
• It is then passed through a sieve of suitable size to obtain granules.
• They are then dried suitably
• The dried granules are then packed and dispensed.
• Granules are usually dissolved in water before administering
• E.g. Granules of antibiotics such as Erythromycin, Nystatin and Penicillin salts.

According to IP, there are two official preparations of granules;
Bephenium hydroxynaphthate granules
o They contain, Bephenium hydroxynaphthate, a bitter drug which is insoluble in
water. It is used as anthelmentic, in the usual strength of 2.5gm per single dose.
Sodium amino salicylate granules
o They contain, Sodium amino salicylate, which has a sweet, saline and unpleasant
taste. It is used to treat TB in a dose of 10 to 15 gm orally.
• Granules containing potent drugs are not packed in bulk, due to the chance of
wrong dose and therefore they are packed in single sachets.

Effervescent granules
o They are specially prepared solid dosage form of medicament, meant for internal
use.
o They produce carbon dioxide, when dissolved in water, which helps in masking the
unpleasant taste of the drug and also helps in easy absorption.
o It contains a Medicament, mixed with
 Citric acid
 Tartaric acid
 Sodium bicarbonate
o Sometimes, saccharin / sucrose may be used as sweetening agent.

o Before administration, the desired qty of granule is dissolved in water.
o The acid and bicarbonate react producing, carbon dioxide in the form of
effervescence.
o This carbon dioxide serves as
 A masking agent, which masks the bitter and saline taste of drugs.
 Also, it stimulates the flow of gastric juice and thereby helps in rapid
absorption of drugs.
 Methods of preparations.
o There are two main methods for preparing effervescent granules;
 Heat method
 Wet method

Heat method;
 A large porcelain or stainless steel evaporating dish is placed over the boiling water
bath.
 The dish must be sufficiently hot before transferring the powder into it, to ensure
rapid liberation of the water of crystallization from citric acid.
 If the heating is delayed, the powder added to it will heat up slowly and the
liberated water of crystallization will go on evaporating simultaneously.
 As a result sufficient water will not be available to make a coherent mass.

o Generally heating process takes 1 to 5 minutes.
o Damp mass is then passed through suitable sieve, to obtain the desired sized
granules.
o It is then dried in a Hot Air Oven at not exceeding 600C.
o Packed in an air tight container

Wet method
 In this method, mixed ingredients are moistened with non-aqueous liquid
(alcohol), to prepare a coherent mass.
 The coherent mass is then passed through a suitable sieve, to obtain granules of
specific size.
 The granules are then dried in a hot air oven not exceeding 600C.
 The granules may be again passed through the sieve to break the lumps, if any
formed.
 The dried granules are then packed in air tight containers.

3. Tablets and Capsules

Tablets
 These are unit solid dosage forms of medicament or medicaments which are
prepared by moulding / compression.
 Certain excipients may also be added to medicaments in the formulation.
 Compressed tablets are prepared in bulk by large scale production methods.
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Capsules
 Capsules are unit solid dosage forms in which one or more medicaments and
excipients are enclosed with in a small shell.
 The shell is generally prepared from gelatin.
 Depending on the formulation, the gelatin capsule may be hard gelatin capsule or
soft gelatin capsule.

4. Pills
 Pills are small rounded solid dosage forms containing medicament that are
intended to be administered orally.
 The medicaments and excipients are mixed to form a firm plastic mass.
 This mass is then put into a uniform pill pipe, in which number of pills can be
manufactured, which may be round, to form a uniform size and shape.
 Pills which are spherical in shape, are made by rolling them under wooden pill
rounder.
 The pills are sometimes coated with varnish, silver leaf, gold leaf etc,
o To improve the finish
o To mask the unpleasant taste
o To increase stability.

 In olden days, pills where more preferred due to its spherical shape and ease of
swallowing.
 But now the pills are out dated due to some disadvantages.
o Disintegration time of pills are uncertain. (disintegration time for freshly
prepared pills are less, whereas old dried pills take more time to disintegrate.
Some dried pills may pass through GIT even without disintegrating.)
o Difficult to prepare pills of uniform size.
o Difficult to prepare pills of uniform weight.

Liquid dosage form
o Liquid dosage forms are medicaments in liquid form which are meant for internal,
parentral or external use. They are available in two forms;
Monophasic liquid dosage form
o These are liquid dosage form, which appear like single phase.
E.g. Syrup, Elixir, Linctuses, Drops, Liniments, Lotion, Gargle, Mouthwash, Throat
paint, Spray, Inhalation, Nasal drop, Eye drop, Eye lotion, Ear drops.
Biphasic liquid dosage form
o These are liquid dosage form, which appear like two phases.
E.g. Suspension, Emulsion

Monophasic liquid dosage forms
o Monophasic liquid dosage forms are represented by true solution or colloidal
solution. They look like a single phase, even though there may be several
ingredients in its formulation.
o The component of the dosage form which is present in large quantity is known as
solvent. Water is mainly used as solvent for majority of monophasic liquid dosage
forms.
o Whereas the component present in small quantity is known as solute.
o A true solution is homogenous because the solute is in an ionic form or molecular
form.
o In case of colloidal solution, solute are present as aggregates, but they cannot be
seen by naked eye or under ordinary microscope.

Monophasic liquid dosage forms are available as;
1. Liquids for internal use
Syrup, Elixir, Linctus, Drops, Draughts
2. Liquids for external use, which can be of two types;
a) Liquids to be applied to the skin
Liniment, Lotion etc
b) Liquids meant for body cavity
Gargles, Throat paint, Mouth washes, Eye drops, Eye lotions, Ear drops, Nasal
drops, spray, Inhalation.

Syrups
Simple syrup is a saturated solution of sucrose in purified water. The concentration
of sugar is 66.67% w/w. The syrups are sweet, viscous preparation. The syrups
containing medicinal substances are called “Medicated syrups”. Those syrups
containing flavoured substances are called “Flavoured syrups”.
Syrups are commonly used dosage forms due to the following Advantages;
1. Syrup retards oxidation, because it is partly hydrolysed into reducing sugars such
as lavulose and dextrose.
2. It prevents decomposition of vegetable substances. It is due to the high osmotic
pressure of syrup which prevents the growth of bacteria, fungi and mould which
are the major causes of decomposition.
3. They are palatable. Due to the sweetness of sugar it can mask the nauseous effect
of substances.

 Syrups are now used for formulating antibiotics, anti histamines, sedatives,
antitussives, vitamins and bitter or saline drugs.
o Syrups are divided into two groups based on the method of preparation:
a. Syrups prepared by simple solution or admixture
e.g. Simple syrup, Ginger syrup, Orange syrup, Lemon syrup.
b. Syrups prepared by process of extraction
e.g. Tolu syrup
Simple syrup IP
Sucrose 667g
Purified water qs 1000g
Add sucrose to purified water and heat it to dissolve with occasional stirring.
Cool it and add more of purified water to make the required weight.

Tolu syrup IP
Tolu balsam 12.5g
Sucrose 660 g
Purified water qs 1000 g
Add boiling purified water to tolu balsam contained in a tarred vessel. Cover
the vessel and boil the contents gently for half an hour with frequent stirring. Add
purified water to adjust the weight. Cool, filter the solution and add sucrose. Heat on a
water bath to dissolve the sucrose. Finally add sufficient purified water to produce the
required weight.

Elixirs
Elixirs are sweet, hydro-alcoholic, aromatic preparations and are usually coloured,
but at the same time clear. Elixirs are of two types;
Medicated elixir – contains usually potent drugs
Flavouring elixir – contains flavours and are used as flavouring agent and vehicle.
The main ingredients of elixirs are;
 Ethyl alcohol
 Water
 Glycerin or Propylene glycol
 Flavouring agent
 Syrup
 Preservatives

SIMPLE ELIXIR IP
Orange tincture 75ml
Syrup 400ml
Chloroform water qs 1000ml
Mix the orange tincture with syrup and add sufficient chloroform water to produce
the required volume. Add talc, shake, allow to stand for few hours, shaking
occasionally and filter.

Linctus
o Linctuses are viscous liquid, oral preparation that are generally prescribed for relief
of cough. They may contain medicaments which have demulcent, sedative or
expectorant action.
o They are taken in small doses, sipped and swallowed slowly without diluting with
water. When taken as such, linctuses give maximum and prolonged action.
o Simple syrup is generally used as vehicle for most linctuses.
o Tolu syrup may also be used as vehicle, due to its aromatic odour and flavour. Also
it has a mild expectorant action.

Codeine linctus BP
Codeine Phosphate 3gm
Lemon syrup 200ml
Benzoic acid solution 20ml
Chloroform spirit 20ml
Water 20ml
Compound tartrazine solution 10ml
Simple Syrup qs 1000ml
 Weigh codeine phosphate and dissolve it in water, heat gently if req. Add benzoic
acid soln, comp. tartrazine soln and chloroform sprit. Add lemon syrup and adjust
the volume by adding simple syrup.

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Drops
o These are liq. preparation meant for oral administration. The oil soluble vitamins
such as vit A and vit D concentrates in fish liver oil are presented as drops for
administration.
o Since these preparations contain potent medicaments, the dose must be measured
accurately. The following two methods are commonly used for this purpose;
1. Use of a dropper which is accurately graduated in fractions of ml.
2. Use of a pre calibrated dropper in which the number of drops equivalent to
the prescribed dose of a particular preparation being administered is known.
o The size of the drops from the ,medicine dropper, depends on the factors such as
surface tension, viscosity, density and temp of the liq.

Liniments
o Liniments are liquid or semi-liquid preparations meant for application to the skin.
They are usually applied using hand, with help of friction and rubbing of the skin.
The liniments may be alcoholic or oily solutions or emulsions.
o Alcohol helps in
 Penetration of medicaments into skin
 Gives a counter irritant action
 Provides a rubefacient action
o Arachis oil may be used in some liniments, which spreads more easily.
o Soap may also be used, which helps in easy application of liniments.

o Medicaments that are generally formulated into liniments are;
Analgesics, Rubefacient, Soothing agents, Counter irritant and Stimulating agents.
o Liniments should never be applied on to broken skin as it may cause excessive
irritation
Turpentine Liniment IP
Soft soap 90gm
Camphor 50gm
Turpentine oil 650ml
Purified water qs1000ml
Mix the soft soap with 100ml of purified water. Prepare a soln of camphor in
turpentine oil. Gradually add camphor soln to soap soln, with trituration until a
thick creamy emulsion is produced. Add sufficient purified water to produce the
req. volume. Mix it thoroughly.

Lotions
o Lotions are liquid preparations meant for external application without friction.
They are applied directly to skin, with the help of some absorbent material such as
cotton wool or gauze, soaked in it.
o Lotions are used for its local action such as cooling, soothing and protective action.
o They are also used for its antiseptic action.
o Alcohol may be used in some preparations for its cooling and soothing effect.

Calamine lotion IP
Calamine 150gm
Zinc oxide 50gm
Bentonite 30gm
Sodium citrate 5gm
Liquefied phenol 5ml
Glycerin 50ml
Rose water qs 1000ml
Dissolve sodium citrate in about 700ml of rose water. Triturate, calamine, zinc
oxide and bentonite with soln of sodium citrate. Add liquefied phenol and glycerin
to it. Add rose water to produce the required volume.

Compare between liniments and lotions
Sl. No. Parameters Liniments Lotions
1 Dosage form
2 Site of application
3 Mode of application
4 Medium used for application
5 Expected ingredients
6
Indented pharmacological
actions
7 Examples

Gargles
 They are aq. Soln used to prevent or treat throat infections.
 They are available in concentrated form with direction for dilution with warm
water before use.
 They are brought into intimate contact with mucous membrane and allowed to
remain there for few seconds before they are thrown out.
 They are usually used to relive soreness in mild throat infections.
 Phenol / Thymol is generally used in small concentrations for antibacterial activity.
 Potassium chlorate may also be used for its weak astringent effect, to tone up the
throat. It also stimulates secretion of saliva which relieves dryness.

POTASSIUM CHLORATE AND PHENOL GARGLE BPC
Potassium chlorate 30gm (astringent & stimulant)
Paten blue V 0.009gm (colouring agent)
Liquefied phenol 15ml (disinfectant & antiseptic)
Water q.s. 1000ml
 Dissolve potassium chlorate in warm water.
 Cool and add liquefied phenol.
 Add the dye soln, filter and make up the volume using vehicle.
 Other examples are Phenol gargle, Povidone iodine gargle.

Mouth washes
 These are aq. soln with pleasant taste and odour. Used to clean and deodorise the
buccal cavity.
 Generally they contain antibacterial agents, alcohol, glycerin, sweetening agent,
flavouring agent and colouring agents etc.
ZINC SULPHATE AND ZINC CHLORIDE MOUTHWASH BPC
Zinc sulphate 20gm (therapeutic & prophylactic in ulcer)
Zinc chloride 10gm (anti mouth odour & synergic effect)
Dil. HCl 10ml (pH maintaining)
Comp tartrazine soln 10ml (colouring agent)
Chloroform water q.s. 1000ml
Dissolve zinc sulphate and zinc chloride in water. Add dil. HCl to make a clear soln.
Add comp tartrazine soln. Add vehicle to make up the req. volume.
 Other examples; Sodium chloride mouthwash, Chlorhexidine Gluconate mouthwash

Throat paints
• Throat paints are viscous liquid preparations used for mouth and throat infections.
• Glycerin – is a main ingredient and commonly used because;
 It is viscous
 Adheres to mucous membrane for long period
 Sweet in taste
• They are applied to the mucous membrane of throat and mouth with the help of a
throat brush (camel hair brush) or cotton swab (cotton plug twisted at the tip of a
plastic stick).
• Now a days throat sprays are also used for its application, which is more
convenient.
• They should be applied as such, without diluting with water.

• Medicaments used in throat paints may be Antiseptic, Anti-infective, Astringent,
Analgesic
• The container should contain the secondary label; “FOR EXTERNAL USE ONLY”
• Examples
 Mandl’s paint,
 Tannic acid – glycerin throat paint
 Phenol – glycerin throat paint
 Crystal violet paint
 Betadine antiseptic paint etc.

IODINE PAINT COMPOUND B P C (MANDL’S PAINT)
Potassium iodide 25gm
Iodine 12.5gm
Alcohol 90% 40ml
Water 25ml
Peppermint oil 4ml
Glycerin q.s. 1000ml

Method
1. Dissolve potassium iodide in water.
2. Add iodine to it and stir until it dissolves
3. Dissolve peppermint oil in Alcohol 90% and transfer it to the above Iodine soln
and mix well.
4. Add small qty of glycerin to it and mix thoroughly.
5. Add more of glycerin in small qty with proper mixing, to make up the volume.
6. Transfer the preparation into a container, corked, polished, labelled and
dispensed.
Iodine soln

Sprays
• Sprays are preparations of drugs in aqueous or alcoholic media or in glycerin.
• They are applied to mucous membrane of nose or throat with the help of an
atomiser.
• The throat sprays may be applied with the help of a special type of atomiser known
as nebuliser, which converts large droplets to fine droplets by baffle system.
• Thus it reaches the lungs, easily.
• The nasal sprays are applied in the form of coarse droplets using atomiser or a
plastic squeeze bottle.
• They are indented to be in the nasal tract.
• E.g. Adrenaline and atropine spray compound BPC

Nasal sprays

Inhalations
• These are liquid preparations containing volatile substances, which relieves
congestion and inflammation of the respiratory tract.
• The volatile substances may be placed on an absorbent pad or handkerchief and
then inhaled there from.
• In some other cases, inhalations are added to hot, but not boiling water (about
650C) and the vapours are inhaled.

BENZOIN INHALATION BPC
Benzoin crushed 100gm
Preparaed storax 50 gm
Alcohol 95% qs 1000ml
It is prepared by macerating, benzoin and prepared storax with alcohol 95% for 24
hrs. Filter the solution and add sufficient alcohol to produce the required volume.

Eye lotion
• These are aqueous solution used for washing of eye.
• They are supplied in concentrated form, which has to be diluted with warm water
before use.
• They must be isotonic with lachrymal secretion and must be free from foreign
particles, to avoid irritations.
• They must be prepared fresh (extemporaneous preparation) and should not be
stored for more than 2 days.
• It may get contaminated with microorganisms.
• E.g. Sodium chloride eye lotion

Nasal drops
• These are aqueous solutions of drops that are instilled into the nose with a
dropper.
• The preparations must be aqueous. Oily vehicles are not used because, oily drops
inhibit the movement of cilia in the nasal mucosa.
• And if used for a longer period, it may reach lungs and cause, lipoid pneumonia.
 Requisites
• Nasal drops should be isotonic
• It should have neutral pH
• Viscosity should be similar to nasal secretion (using 0.5% methyl cellulose)
• Nasal preparation must not interfere with cleansing action of
epithelial cilia.

Common ingredients
Phosphate buffer of pH 6.5 is used as vehicle.
Labelling
The label should state that
“FOR EXTERNAL USE ONLY”
OR
“FOR USE IN NASAL TRACT ONLY”
Storage
Nasal drops should be stored in a cool place.
69 Lisie College of Pharmacy, Kochi

EPHEDRINE NASAL DROPS
Ephedrine hydrochloride 0.5gm
Chlorobutanol 0.5gm
Sodium chloride 0.5gm
Water q.s. 1000ml
Method
• Dissolve ephedrine hydrochloride, chlorobutanol and
sodium chloride in warm water.
• Cool, filter (if necessary) and make up the volume
through filter.
• Transfer the nasal drops to the container,
polish and labelled

Ear drop
 Definition
These are solutions of drops, that are instilled into the ear with a dropper. It is
generally prepared in vehicles such as, water, glycerin, propylene glycol or dilute
alcohol.
 Uses
The ear drops are generally used for
 cleaning the ear
 softening the wax
 treating mild infections

Containers
Ear drops are dispensed in coloured, fluted glass bottles with a dropper in the cap.
They are also dispensed in a suitable plastic container
Labelling
The label should state that
“FOR EXTERNAL USE ONLY”
OR
“FOR USE IN EAR ONLY”
“Store in a cool place”

SODIUM BICARBONATE EAR DROPS BPC
Sodium bicarbonate 5gm
Glycerin 30ml
Purified water q.s. 100ml
Method
• Dissolve sodium bicarbonate in few ml of water.
• Add glycerin to it and mix well
• Add more of vehicle to make up the volume
• Transfer to a bottle, polish, label and dispense.

Eye drops
• These are sterile solutions or suspensions of drugs that are instilled into eyes with
dropper.
• They are usually made in aqueous vehicle.
• It should be;
• Sterile
• Isotonic with lachrymal secretion
• Buffered
• Free from foreign particles
• A suitable preservative like phenyl mercuric nitrate, benzalkonium chloride,
chlorhexidine acetate etc may be used to prevent bacterial growth.
• Generally used medicaments are; Antiseptic, Anti-inflamatory, Anaesthetic, Miotic
drugs.
To avoid irritation

General method of preparation
o Dissolve medicament in aq. vehicle with any one of the preservative or others
specified in monograph
o The solution is clarified by filtration
o Transferred to final container and corked
o Sterilisation is done either by;
autoclaving.
heating with bactericide at 980C to 1000C for 30mins.
filtration through bacteria proof filter.

Packaging
o Should be packed in neutral glass containers / suitable plastic container
o Glass droppers are also made of neutral glass
o The teats of dropper are made of rubber

Precautions to be taken while using eye drop
o If dropper is separated, hold the tip downward
o Never touch dropper surface
o Never rinse the dropper
o Never use colour changed eye drops
o Make sure the cap is not contaminated, when removed.
o After instillation, do not close the eyes tightly or do not blink the eyes frequently.
This may remove the medicament from the place where it is intended.

BIPHASIC LIQUID DOSAGE FORM
(EMULSION AND SUSPENSION)
79

Basic difference b/w suspension and emulsion?
80
SUSPENSION EMULSION
BIPHASIC
(Two phases) – Solute & Solvent
Solute – Liquid
Solvent - Liquid
Solute – Solid
Solvent - Liquid
Insoluble /
immiscible
Dispersed
phase – solid
Continuous
phase - liquid
Dispersed
phase – liquid
Continuous
phase - liquid

EMULSION
Definition
 Emulsion is a biphasic liquid preparation containing two immiscible liquids, one of
which is dispersed as minute globules into the other.
The liquid converted to minute globules – dispersed phase
The liquid in which globules are dispersed – continuous phase
 Normally – 2 immiscible liquids alone – cannot exit as dispersed form – for long
time.
 So an emulsifying agent – added to the system
 It forms a film around the globules – reduces IT – helps to scatter uniformly – stable
emulsion formed.

Formation of o/w or w/o
type emulsion
Orientation of surfactant
Natural emulsion

Advantages
• Medicines having unpleasant taste and odour – can be made more palatable
• Protection for drugs – prone to oxidation and hydrolysis
• Novel preparations – creams, lotions, foam aerosols – formulated as emulsions
• Sterile IV emulsions can be prepared and administered
• Emulsion improves absorption of oils – when taken orally
• Radio opaque emulsions can be prepared – used as diagnostic agents

Types
I. Based on globule size
Usual globule size of emulsion – 0.25µm to 25µm
• Coarse emulsion – large globules
• Fine emulsion – globule size of 5µm
• Micro emulsion – small as 10nm
(Emulsions are milky / white due to reflection and refraction at many interfaces
and almost transparent if the RI are almost same for two phases)

II. Based on dispersed phase / continuous phase
Oil in water type (o/w)
Water in oil type (w/o)
Multiple emulsion
w/o/w type
o/w/o type

o/w type emulsion
Dispersed phase?
Oil phase
Continuous phase?
Aqueous phase
w/o type emulsion
Dispersed phase?
Aqueous phase
Continuous phase?
Oil phase
Preferred for Internal use
Emulsifying agents used;
Gum acacia, tragacanth, methyl cellulose, saponins
and soaps formed from monovalent bases like Na+, K+
and NH4
+
Preferred for External use
Emulsifying agents used;
Wool fat, resin, beeswax
and soaps formed from divalent bases like Ca++, Mg++
and Zn++

Identification test for emulsion
 Dilution test
 Dye test
 Conductivity test
 Fluorescence test

o/w type
Stable
Dilution test

w/o type
Phase inversion / Breaking
(Unstable)

In short
Diluent liquid Water Oil
Stability Stable Unstable Stable Unstable
Continuous
phase
Water Oil Oil Water
Dispersed
phase
Oil Water Water Oil
Type o/w w/o w/o o/w

Dye test
Scarlet red (oil
soluble dye)
o/w type
w/o type
Oil phase
(Appears red in colour)
Aqueous phase
(Appears colourless)
Oil phase
(Appears red in colour)
Aqueous phase
Observed
Under
microscope

Methyl Blue
(aqueous soluble
dye)
o/w type
w/o type
Oil phase
Aqueous phase
(Appears blue in colour)
Oil phase
Aqueous phase
(Appears blue in colour)
Observed
Under
microscope

Conductivity test
Basic concept; Water – good conductor & Oil – bad conductor of electricity
 Dip a pair of electrodes in, emulsion to be identified and connected to a low
voltage bulb. Then pass electric current through it
+
-
o/w type emulsion
Bulb glows
Oil phase
Aqueous phase

If the bulb glows – emulsion is o/w type – because water is the continuous phase
If the bulb doesn't glow – emulsion is w/o type – because oil is the continuous phase
+
-
w/o type emulsion
Bulb doesn’t glows
Aqueous phase
Oil phase

Fluorescence test
Basic principle; certain fixed oils (olive)
produce fluorescence
in presence of UV light
Certain fixed oil
o/w type
w/o type
Oil phase
(Florescence)
Aqueous phase
(No Florescence)
Oil phase
(Florescence)
Aqueous phase
(No Florescence)
Microscopic
observation
Under UV

Classification of Emulsions
Classification of emulsion is done on two basic aspects;
I. Based on the type of emulsifying agent used in preparation
a. Emulsions containing natural gum (gum acacia, tragacanth, Irish moss)
b. Emulsions containing gum substitute (cellulose and its derivatives)
c. Emulsions containing various soaps (divalent and bivalent soaps)
d. Emulsions containing saponins
e. Emulsions containing starch
f. Emulsions containing natural waxes (wool fat, beeswax)
g. Emulsions containing synthetic waxes (cetomacrogol wax)
h. Emulsions containing other emulsifying agents (pectin, egg yolk, gelatin)

II. Based on their mode of administration
Emulsions are classified – three – according to its use/mode of administration.
1. Emulsions for oral administration
2. Emulsions for IV administration
3. Emulsions for external application

 Emulsions for oral administration
 Generally o/w type
 Used for administering medicinal oils.
 The emulsification – helps – increases palatability – by masking disagreeable taste
of oil and “oily feel” of medicinal oil.
 E.g. Liq. Paraffin emulsion (formulation)

 Emulsions for IV administration
 Oil soluble medicinal comps such as – sex hormones, vit A, D and K – administered
as IV injections
 Some times they are also used as diagnostic aids
 These emulsions – must have – small globule size and must be sterile.
 Emulsions for external application
 Emulsions of both o/w type and w/o type – used for external application
 But o/w type is most preferred
 Some drugs when emulsified – rate of penetration through skin reduces – results in
prolonged action.
 Emulsions applied to skin are generally semi-solid. Acts as an excellent vehicle.

SUSPENSION
 Definition
Suspensions are biphasic liquid dosage forms of medicament in which finely
divided solid particles ranging from 0.5 to 5.0 micron are dispersed in a liquid.
Here the solid particles act as dispersed phase whereas liquid phase acts as
continuous phase. Suspensions are used orally, parentral and externally.
Significance of particle size and route of administration
Suspension - external application – sufficiently small particle size – to avoid gritty
feeling. Also helps in easy application to skin & in rapid penetration.
Suspension - parentral administration – particle size that can pass through the needle.
Suspension instilled into eye – free from gritty particles – to avoid irritation.
Suspension administered orally – particle size should not be beyond 10micron.

 Qualities of a good suspension
1. It should settle slowly and should be readily re-dispersed on gentle shaking of the
container
2. It should pour readily and evenly from the container.
3. It should be chemically inert
4. The suspended particles should not form a hard cake.
5. It should be free from large particles which may spoil the appearance and cause
irritation.
6. The particle size should remain almost constant throughout its life period.

 Now a days – suspensions – supplied as dry powders.
 This is to minimize the possibility of microbial attack.
 How?
 These suspensions – marketed as dry powder – with proper direction to mix with
certain amount of a vehicle – convert it into actual suspension.
 They may be administered instantaneously or kept for a limited period of time.
 Thus – stability of suspension – ensured.
 e.g. Ampicillin oral suspension IP
Insulin Zinc suspension
Barium sulphate suspension IP

Precautions to be considered
 Suspensions – packed in containers – with adequate air space above the liquid.
This is to permit adequate shaking
 Oral suspensions – packed in wide mouthed bottles
This is to permit easy removal of the contents
 Suspensions – stored in tight containers, protected from freezing, heat and light.
This is to make the suspension stable.
 Suspension – shaken well before use
This is to ensure uniform distribution of medicament – thereby – uniform and
proper dosage.

SEMI - SOLID DOSAGE FORMS
• Semi solid dosage forms are mainly meant for external application.
• Ointments
• Creams
• Pastes
• Jellies
• Suppositories etc...

 Ointments
 These are semi solid preparations – application to skin or mucous membrane.
 Contain a medicament – dissolved / suspended / emulsified – ointment base.
 Will also contain – antimicrobial agent
 Simple Ointments – used – protective or emollient action
 Medicated Ointments – used – action on
epidermis or
deeper layers of cutaneous tissues or
more deeper & release medicament to body fluids.

Ophthalmic ointment
 Meant for application to eye.
 Sterile & free from irritation
 In the preparation of ophthalmic ointments – yellow soft paraffin preferred over
white soft paraffin.
 White soft paraffin – contain – traces of bleaching agent – left behind after
beaching of yellow soft paraffin to white soft paraffin.
 These traces of bleaching agent – irritation.
 To avoid this – yellow soft paraffin preferred over white soft paraffin – ophthalmic
preparations.

An ideal ointment base should have the following properties;
1. Should be inert, odourless and smooth
2. Physically and chemically stable.
3. Compatible with skin and other incorporated ingredients.
4. Proper consistency – easily spreads and softens on application to skin.
5. Should not retard healing of wounds
6. Should not produce irritation and sensitization of skin.
There is no single ointment base – possessing all the qualities.
So – prefer to use a mixture one or more ointment base.

Classification of ointment bases;
 Oleaginous bases
 Absorption bases
 Emulsion bases
 Water soluble bases

Oleaginous base
Consist of water soluble – hydrocarbons, vegetable oils, animal fats and waxes.
Oleaginous base;
 Helps – keep medicament – prolonged contact – skin
 Act as occlusive dressing
 Low capacity to absorb water
 Emollient action
Soft paraffin
Hard paraffin
Liquid paraffin
Lower the MP &
soften bases of
high consistency.
Lard
Advantages

Disadvantages
 Greasy in nature
 Sticky and difficult to remove from cloth and skin
 Retain body heat – feel uncomfortable warmth
 Do not help in absorption of medicament

Absorption bases
Generally anhydrous substances which, have the property of absorbing
considerable qty of water – still retain ointment like consistency.
Absorption bases – two types;
 Non-emulsified bases
 Water in oil emulsion
Non – emulsified bases absorb water & aq. soln. – producing w/o emulsion
e.g. Wool fat (anhydrous lanolin), wool alcohol, bees wax and cholesterol.
Water in oil emulsion absorb more amt of water – have the property of non-
emulsified bases
e.g. Hydrous wool fat (lanolin)

Emulsion bases
 Generally semisolid / creamy like consistency.
 o/w & w/o emulsions – used as ointment base.
 o/w type - most popular – they can be easily removed from skin and cloth.
 w/o type – greasy and sticky
Compound benzoic acid ointment (whitfield’s ointment) is prepared using
emulsifying ointment – prepared from emulsifying wax, white soft paraffin and
liquid paraffin.

Water – soluble bases
 Commonly known as “greaseless ointment bases”
 Consist of water soluble ingredients – PEG (commonly known as carbowaxes)
 Carbowaxes - water soluble, non-volatile, inert.
 Consistency vary – depending – MW.
 Commonly used PEG – PEG 400, PEG 1500, PEG 4000 and PEG 6000.
 Mixing diff. carbowaxes – ointments – desired consistency – obtained.

 Creams
 Viscous semi solid emulsions – meant for external application
 They are of two types;
Aqueous creams
(o/w type emulsion)
Oily creams
(w/o type emulsion)
 Storage
 Stored & supplied – well closed container – prevent evaporation & contamination.
 Collapsible tubes of metal or plastic – may be used.

Aqueous Creams
 Anionic, cationic and non-ionic waxes
 Polysorbate
 Triethanolamine soaps
 A suitable preservative is added to Aq. creams – they have tendency for bacterial
growth.
Oily Creams
 Wool fat
 Wool alcohol
 Beeswax
 Calcium soaps
Emulgents used
Emulgents used

 Pastes and Jellies
Sl.
No.
Pastes Jellies
1
Semi-solid preparation for external
application
Transparent / translucent, non-greasy,
semi-solid preparation for external
application
2
Contain zinc oxide, calcium carbonate,
starch
Contain gelatin, starch, tragacanth,
sodium alginate, cellulose derivatives
3
Used as antiseptic, protective and
soothing dressings
Used for lubricating catheters, surgical
gloves and rectal thermometer
4
Have high proportion of powdered
medicament
Now a days popular for contraceptive
purposes
5
Stored and supplied in containers that
do not allow absorption of
medicaments.
Contain surfactants that enhance
spermicidal property

 New drug delivery systems
 Implants
 Films & strips
 Liposome
 Controlled drug delivery modules
 Erythrocytes
 Nanoparticles
 Prodrugs

Implants
 Hormonal therapy
 Hypodermic tablets
 Magnetically controlled implants
 Placed @ upper thigh – 5mm depth
 AlNico rod magnet

Films and Strips
 Zero order release films
 Laminates
 Topical application
 Nitroglycerin laminates
 Release drug – 12 hrs
 Buccal strips
 Placed to buccal cavity
 Base of fabric/filter paper/cotton
 Base dipped in molten carbowax & drug mixture
 Strip – made to contact with buccal mucosa – 15 mins - removed and discarded

 Spray bandages
 Solution of drug in polylactide
 Sprayed on external skin surface – forms a bandage
 Simply washed off – after use – with warm water

Liposome
 Bi layered Phospholipids – capable to carry – hydrophillic and hydrophobic drugs
 Large multilamellar vesicles (LMLV)
 Small unilamellar vesicles (SUV)
 Large unilamellar vesicles (LUV)

Controlled drug delivery modules (CDDM)
 Drug in a polymeric matrix
 Polymeric matrix hold and release the drug – plyethylenes, silicone elastomer,
cellulose esters.
 CDDM – tablets/capsules
 Punctured before administration – laser beam – small orifice
 Drug released by - diffusion/osmosis/chemical reaction

Erythrocytes
 Helps in slow release of drug
 More combatable with body
 Can be sent to almost all parts of body
 Resealed erythrocytes
 First in hypotonic solution – containing drug
 Then tonicity is reestablished – gets sealed

Nanoparticles
 A drug-carrier mechanism is used
 The complex – nanometer range – NANOPARTICLE
 Carrier – naturally occurring macromolecule (HSA, Bovine Serum Albumin etc)
 Drug mixed with carrier in aq. sol. (if drug – hydrophobic – mix with small amt of
organic solvent – than mix with carrier in aq. sol.)
 Desolvated using sodium sulphate or alcohol
 Nanoarticles are obtained

Prodrugs
 Compounds that undergo biotransformation – before showing pharmacological
activity
 Generally esters or amides of parent drug
 Improves;
 Stability
 Solubility
 Bioavailability
 Masking unpleasant taste and odour
 Reduce drug toxicity

Introduction to dosage forms

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