LEARNING OBJECTIVES:
At the end of this lecture, students will be able to:
 Know about extemporaneous dispensing.
 Define different dosage forms
 Classify different dosage forms on the basis of their
use with examples (solutions, suspensions, creams,
emulsions, ointments, paste, gels, suppositories,
pessaries, powders, granules, oral unit dosage forms)
 Contrast different dosage forms
 Dispense different dosage forms extemporaneously
with labels.
 Evaluate dispensed dosage forms and their labels.
 Provide special labels and advice for patients.
Dispensed products grouped into
 Solution
 Suspension
 Emulsion
 Creams
 Powders and oral unit-dosage forms
 Ointments
 Pastes & jellies
 Suppositories & pessaries
SOLUTIONS:
 Homogenous liquid preparations
 Containing one or more dissolved ingredients
 Designed for internal & external use.
FORMULATION OF SOLUTION:
Following should be determined before formulating a
solution:
1. Vehicles
2. Solubility
3. additives
VEHICLES:
Medium in which ingredients of medicine are dissolved
or dispersed.
 Water
 Syrup
 Ethanol
 Glycerol
 Propylene glycol
 Acetone
 Solvent ether
SOLUBILITY:
 “The no. of parts of solvent (by volume) that will
dissolve one part (by weight of a solid or volume of a
liquid )of the substance.
 For oral solutions, ethanol, glycerol and propylene
glycol may be used in various combinations with
water as cosolvent.
 Surfactant can be used for solubilization of poorly
water soluble medicaments. E.g. polysorbates.
ADDITIVES
 GIT can tolerate solutions with a wide range of pH
values.
 Hypertonic solutions (potassium citrate mixture BP)
should be well diluted before taking orally.
 Solutions prepared for mucosal surfaces (nasal drops)
usually include sodium chloride to increase tonicity
to that of body fluids.
 Stabilizers
 preservative
 Colours
 Flavours
SOLUTIONS AS ORAL DOSAGE FORMS:
 Elixirs, mixtures & oral solutions contain one or
more ingredients dissolved in a suitable vehicle.
 If dose less than 5 ml prescribed, oral liquid usually
diluted.
 Choice of diluent is critical as their inclusion can
adversely affect flavour, stability or appearance.
 Extemporaneously
dispensed products usually
diluted with water or syrup, appears as last line in the
formula.

 SHELF
LIFE:
 SUPPLY
OF PRODUCT WITH
SHORT HALF LIFE:
 Quantity of product supplied to patient
must not exceed that which would be
expected to be used with in the shelf
life.
 CONTAINERS,
LABELS
AND
ADVICE FOR PATIENTS:
MOUTHWASHES AND GARGLES:
 These are usually diluted with warm water before
use
 Most are not intended to be swallowed in significant
amounts.
 Long shelf life
 Stable products
 Prepared from stock.
 Extemporaneously prepared or poured preparations
are supplied in amber colored fluted bottles or
medicine bottles for products intended to be
swallowed.

SOLUTIONS INSTILLED INTO BODY CAVITIES:
 Nasal drops and sprays formulated as iso osmotic with
nasal secretions.
 Buffered
 Shelf life of extemporaneous products
 Dispensing:
 extemporaneous nasal drops supplied in hexagonal,
amber fluted glass bottles with a rubber teat and dropper
closure.
 Nasal sprays packed in flexible plastic bottles or
pressurized containers.
 For decongestant drops, patient should “AVOID
EXCESSIVE USE” and “AVOID USE IN VERY
YOUNG BABIES UNLESS UNDER MEDICAL
ADVICE”
EAR DROPS:
 Water, glycerol and propylene glycol may be used as
vehicles.
 They are supplied in glass bottles with a teat and
dropper closure or plastic squeeze bottles.
ENEMAS:
 Used for cleansing, therapeutic or diagnostic
purposes.
 shelf life
 Amber fluted glass bottles used for enemas and
disposable bags sealed to a rectal nozzle are for
commercial use.
 Label is marked as “FOR RECTAL USE ONLY”
SOLUTIONS FOR EXTERNAL USE:
 Liniments, lotions and paints are usually stable.
 Shelf-life of liniments, lotions and paints
 Containers for liniments, lotions and paints
 Special labels and advice for patients .
 Antiseptic and disinfectant solutions
 Shelf-life of antiseptic and disinfectant solutions
 Containers for antiseptic and disinfectant
solutions
 Special labels and advice for patients
PHARMACEUTICAL SUSPENSION:
 Suspensions are classified as:
1. Coarse suspensions.
2. Colloidal suspensions.
FORMULATION OF SUSPENSION:
 Water is usually vehicle of choice.
 Non aqueous vehicle like fractionated coconut oil
are occasionally used.
 Other
additives
are
buffers,
stabilizers,
preservatives, colors and flavors.
PROPERTIES OF A GOOD PHARMACEUTICAL
SUSPENSION
FACTORS AFFECTING PROPERTIES OF A
PHARMACEUTICAL SUSPENSION:
 Diffusible solids
 Stokes law
 Control of particle size
 Flocculation
 poorly wettable solids
 In diffusible solids
THICKENING AGENTS:
 Polysaccharides i.e. acacia gum, tragacanth, sodium
alginate, starch.
 Water soluble celluloses i.e. methyl cellulose, hydroxyethyl
cellulose, sodium carboxymethyl cellulose.
 Clays i.e. bentonite, aluminium magnesium silicate,
hectorite.
 Synthetic thickeners i. e. carbomers, colloidal silicon
dioxide.
BASIC TECHNIQUES FOR PREPARING
PHARMACEUTICAL SUSPENSIONS
SUSPENSIONS AS ORAL DOSAGE FORMS
 MIXTURES:
 Advantages of suspensions as oral dosage forms
 Disadvantages of suspensions as oral dosage
forms
 Shelf life of oral suspensions
 Containers for oral suspensions
 Special labels and advice for patients
SUSPENSIONS FOR EXTERNAL USE
 LOTIONS:
• containers for lotions
• Special labels and advice for patients
 INHALATIONS
• Containers for inhalations
• Special labels and advice for patients
 OTHER TYPES OF DISPENSED PRODUCT
 SUSPENSIONS AS 'EMERGENCY'
FORMULATIONS
 EMULSION:
 An
emulsion is a disperse system consisting of
two immiscible liquids, one of which(disperse
phase) is finely divided and distributed through
the other (continuous phase).
 DETERMINATION OF EMULSION TYPE
 To distinguish between O/W and W/O emulsions,
following tests may be used:
1. Miscibility test
2. Microscopic examination after staining with a oil
soluble dye
3. Microscopic observation under UV radiation
4. Conductivity measurements





1.
2.
3.

FORMULATION
Emulsifying agents facilitate the production of a
dispersion by reducing interfacial tension and maintain
the separation of the droplets of the dispersed phase by
forming a barrier at the interfaces.
For oral/parenteral administration, O/W emulsions are
required
For external use both O/W and W/O systems may be
used.
TYPES OF EMULSIFYING AGENTS
Synthetic or semi synthetic substances
Natural products
Finely divided solids
Many of the substances described as thickening agents
also act as amulgents.
SYNTHETIC
OR
SEMI
SYNTHETIC
SUBSTANCES
 They are further classified depending on their
ionization in aqueous solution as follows:
(a) Anionic surfactants e.g. alkali metal and ammonium
soaps, amine soaps, soaps of di valent & tri valent
metals, alkyl phosphate and alkyl sulphates.
(b) Cationic surfactants e.g. quarternary ammonium
compounds like cetrimide
(c) Non ionic surfactants e.g. glycol and glycerol esters,
sorbitan esters, polysorbates, macrogol ethers and
esters
(d) Ampholytic or amphoteric surfactants which are not
widely used as emulsifiers in pharmacy.
 NATURAL PRODUCTS
 FINELY DIVIDED SOLIDS
1.
Choice of an emulsifying agent
 Selection of appropriate emulsification system
depends on active ingredients incorporated into
product and on use of final product and based on
theoretical considerations and on experience.
Formulation by the HLB method
 emulgents with high numbers (8-18) produce o/w
emulsions and with low numbers (3—6) give w/o
emulsions.
OTHER ADDITIVES
Antioxidants:
e.g. butylated hydroxyanisole (BHA) or butylated
hydroxytoluene (BHT). Ethyl, propyl or dodecyl gallate may
also used.
Preservatives
Desirable properties of a preservative for emulsions
Preservatives commonly used in emulsions
 Organic acids.
 Parahydroxybenzoic acid esters.
 Chlorocresol.
 Phenethyl alcohol.
 Quaternary ammonium compounds.
 Chloroform.
Colour and flavor
 Additional color is rarely necessary.
 Flavors are used for oral emulsions.
STABILITY OF EMULSIONS :
The main difficulties encountered in practice are listed here.
Creaming
 This is separation of the emulsion into two regions, one
containing more of the disperse phase, e.g. cream on milk.
Cracking
 This involves coalescence of dispersed globules and
separation of the disperse phase as a separate layer.
Phase inversion
 The most stable range of disperse phase concentrations is
30-60%.
 If amount of disperse phase increased until it approaches
or exceeds the theoretical maximum of 74% of the total
volume then phase inversion may occur, i.e. from o/w to
w/o, or from w/o to o/w.
COMPOUNDING OF EMULSIONS AND CREAMS
 Basic techniques are:
1. Weighing
2. Measuring of liquids
3. Mixing
 On small scale mortar and pestle are used producing
globule size larger than 10 µm.
 Homogenizers are used for extemporaneously
prepared emulsions.
EMULSIONS AS ORAL DOSAGE FORMS
 Shelf-life of oral emulsions
 Containers for oral emulsions
 Special labels and advice for patients
EMULSIONS FOR EXTERNAL USE:
 Liniments and lotions are liquid or semi
liquid emulsions designed for application to
skin.
 Shelf-life of applications, liniments and
lotions
 Containers for applications, liniments and
lotions
 Special labels and advice for patients
 CREAMS:


They are viscous semi solids for external use.
They may be W/O or O/W emulsions.
 GENERAL
COMPOUNDING PROCEDURE
FOR CREAMS
 DILUTED CREAMS
 SHELF-LIFE OF CREAMS
 CONTAINERS FOR CREAMS
 SPECIAL LABELS AND ADVICE FOR
PATIENTS
OINTMENTS PASTES AND GELS:
 Ointments are greasy preparations.
 Gels are transparent or translucent, non greasy, aqueous
preparations.
 Pastes contain a higher proportion of finely powdered
medicament than ointments or gels
BASES FOR OINTMENTS AND OINTMENT TYPE
PASTES
They may be classified into four main groups:
 HYDROCARBON BASES
 ABSORPTION BASES
 WATER MISCIBLE BASES
 WATER SOLUBLE BASES
 OTHER
ADDITIVES FOR OINTMENTS
AND PASTES
 These include:
 Antioxidants like BHT, BHA, EDTA and
must be compatible with the medicaments
incorporated into the base.
 Preservatives, which may not be required in
anhydrous ointments. Examples are sorbic
acid, quaternary ammonium compounds etc.
FORMULATION OF GELS:
 Gelling agents are either organic hydrocolloids or
hydrophilic inorganic substances.
 Slightly viscous gels may be used as replacement
solutions for body secretions i.e. artificial saliva
and tears.
 More viscous gels may be used as lubricants for
catheters, examination gloves and surgical
instruments.
 Those designed for surgical or ophthalmic use
must be supplied sterile.
TRAGACANTH GELS:
Concentration of tragacanth from 2%-5% produce
gels of increasing viscosity.
SODIUM ALGINATE GELS:
A concentration of 1.5% produces fluid gels and 510% gels are suitable as dermatological vehicles.
PECTIN GELS
CELLULOSE DERIVATIVES:
POLYVINYL ALCOHOLS:
The required concentration is usually between 10%
and 20%, depending on the grade of PVA and the
desired viscosity.
 OTHER ADDITIVES FOR
GELS:
1.
HUMECTANTS: Like glycerol, propylene
glycol or sorbitol solution may be added to retain
water, otherwise skin formation may occur.
2.
PRESERVATIVES: like methyl and propyl
hydroxybenzoates either alone or in combination
are suitable for gels containing pectin, carmellose
sodium, sodium alginate, tragacanth, etc.
3.
CHELATING AGENTS: like EDTA may be used
for protection against heavy metals.
 COMPOUNDING
OF
OINTMENTS
AND
PASTES
 The
basic techniques are weighing, measuring of
liquids, size reduction, size separation and
mixing.
 MIXING
BY FUSION
 PREPARATION
OF MEDICATED OINTMENT
AND PASTES BY FUSION
 MIXING
BY TRITURATION

SHELF LIFE OF OINTMENTS, PASTES AND
GELS

CONTAINERS FOR OINTMENTS, PASTES AND
GELS

Extemporaneously prepared ointments and pastes are
usually packed in screw capped amber glass or
plastic pots.

SPECIAL LABELS FOR OINTMENTS, PASTES
AND GELS

Store in a cool place.

Sterile.

The labels for collapsible tubes should be fixed to the
upper(nozle) end of the tube.







1.
2.
SUPPOSITORIES:
They are solid medicated preparations designed for
insertion into rectum.
They melt, dissolve or disperse and exerts a local or
systemic effect.
Pessaries similar solid medicated preparations designed
for insertion into the vagina.
Usually used to provide local effect.
FORMULATION OF SUPPOSITORIES AND
PESSARIES:
There are two main classes of suppository base:
Fatty bases designed to melt at body temperature.
Water soluble or water miscible bases designed to
dissolve or disperse within the body.
PROPERTIES OF IDEAL SUPPOSITORY BASE:
1.
(a)










FATTY BASES:
Theobroma oil (cocoa butter):
Advantages of theobroma oil include:
Disadvantages of theobroma oil include:
Polymorphism
Adherence to the mould
Softening point too low for hot climates
Melting point reduced by soluble ingredients
Rancidity on storage
Poor water-absorbing ability
Leakage from the body
expense
(b) Synthetic hard fat:
 They include mixture of mono-, di- and tri-glycerides
of saturated fatty acids.
Advantages of these bases over theobroma oil:
Disadvantages of synthetic bases include:
(2)Water soluble and water miscible bases:
(a) glycero-gelatin
 Mixture of glycerol and water gelled by the addition of
gelatin.
(b)Gelatin
 Two type of gelatin are used in pharmaceutical
preparations:
 Type A which behaves as a cationic agent and most
effective at pH 3.2.
 Type B which behaves as a anionic agent and most
effective at pH 7-8.
(c) Macrogols (polyethylene glycols)
 Mixtures of macrogols can be used as bases for
suppositories and pessaries.
OTHER ADDITIVES
 Antioxidants can be added to prevent oxidation
which must be compatible with the medicament.
 Water miscible or water soluble bases should
include preservative which must be challenged with
appropriate micro organisms to test its efficacy.
 Emulsifying agents (wool fat, macrogols) may be
included to facilitate incorporation of aqueous
solutions or polar liquids but with caution.
 Hardening agents are added to the base to raise the
melting point.
 Viscosity modifiers reduce the sedimentation rate.


CHOICE OF SUPPOSITORY OR PESSARY BASE

COMPOUNDING OF SUPPOSITORY OR PESSARY
BASE

SUPPOSITORY OR PESSARY MOULDS
 For small scale, metal moulds are used having 6
cavities usually.
 Normal capacities of commonly used moulds
include 1, 2, 4 and 8 g.

DISPLACEMENT VALUES
Use of displacement values (Method for determining displacement value)
Using a nominal 1 g mould, Prepare and weigh six suppositories of unmedicated base = ag
Prepare base containing 30% medicament, fill six moulds and weigh six suppositories = bg
Calculate the amount of base, cg and medicament d g in the six suppositories c = 70% b and d = 30%
b
Therefore the amount of base displaced by
displacement value = __d______
a-c
For example:
Weight of six unmedicated suppos. = 6.0 g
Weight of six suppos. Containing 30% drug = 7.5 g
Base = 70% of 7.5 = 5.25
Drug = 30% of 7.5 = 2.25
Base displaced by 2.25 g = 6 - 5.25 = 0.75 g
Therefore the displacement value of the drug = 2.25/0.75 =3
Method for using displacement value
Required: to prepare for 8 suppositories each containing 300 mg drug of displacement value 3 using a
nominal 1 g mould.
Total amount of drugs required = 8 x 300 mg = 2.4 g
This will displace 2.4/3= 0.8 g of base
Therefore amount of base required = 8-0.8 = 7.2 g
MOULD LUBRICATION
Preparation of suppositories with a fatty base
1. Calculate the quantities required.
2. Prepare the mould.
3. Prepare the base.
4. Prepare the medicament.
5. Melt the base.
6. Incorporate the medicament.
7. Fill the mould.
8. Remove the excess.
9. Open the mould.
Preparation of suppositories with a macrogol base
Preparation of suppositories with a glycerogelatin base
1. Calculate the quantities required.
2. Prepare the mould.
3. Prepare the medicament.
4. Prepare the base.
5. Heat treatment of the base.
6. Adjustment of base to weight.
7. Incorporate any medicament.
8. Fill the mould.
SHELF LIFE:
 Stable preparations if the packaging provides adequate
protection and that the storage temperature is low.
CONTAINERS
LABEL AND ADVICE
1. Store in a cool place.
2. For rectal use only.
3. For vaginal use only.
EXAMPLES
 Compound bismuth subgallate suppositories BP
 Dimenhydrinate suppositories
 Glycerol suppositories BP
POWDERS:
 Undivided oral powders.
 Divided oral powders.
 Granules for oral administration.
 Dusting powders for external use.
 FORMULATION OF POWDERS AND GRANULES:

 COMPOUNDING:
 Basic




techniques of compounding of powders and
granules are:
Weighing
Size reduction
Size separation
Mixing
PREPARATION
OF
UNDIVIDED
ORAL
POWDERS:
 PREPARATION
OF
DIVIDED
ORAL
POWDERS:
 WRAPPING DIVIDED POWDERS:
 PREPARATION OF GRANULES:
On small scale, granules are made with a mortar
and pestle and suitable sieves.
 PREPARATION OF DUSTING POWDERS:
They are prepared using method as for undivided
oral powders.
Sieve size should be 180 µm.

ORAL POWDERS AS DOSAGE FORMS:
1. UNDIVIDED POWDERS AS ORAL DOSAGE FORMS:
 Relatively few medicaments are formulated as undivided/divided
powders.
 ADVANTAGES AND DISADVANTAGES OF UNDIVIDED
POWDERS:
 SHELF LIFE OF UNDIVIDED POWDERS:
 Undivided powder are suitably packaged and stored.
 Remain stable over a long period.
 CONTAINERS OF UNDIVIDED POWDERS:
 Plain glass jars with close fitting closures and a 5 ml measuring
spoon should be supplied for undivided powders.
 SPECIAL LABEL AND ADVICE FOR PATIENTS:
2. DIVIDED POWDERS AS ORAL DOSAGE FORMS:
 SHELF LIFE OF DIVIDED POWDERS:
 CONTAINERS OF DIVIDED POWDERS:
 SPECIAL LABEL AND ADVICE FOR PATIENTS:
3. GRANULES AS ORAL DOSAGE FORMS:
 Bulk granules can be used to deliver medicaments of low
potency.
 Granules packed in individual sachets.
 SHELF LIFE OF GRANULES
 CONTAINERS OF GRANULES
 SPECIAL LABEL AND ADVICE FOR PATIENTS:
 GRANULES FOR MIXTURES:
 Some antibiotics are unstable in solution or suspension, which
are formulated by manufacturers as dry granules containing
medicaments and various adjuncts.
4. BULK POWDERS FOR EXTERNAL USE
 SHELF LIFE OF DUSTING POWDERS
 CONTAINERS OF DUSTING POWDERS
 SPECIAL LABEL AND ADVICE FOR PATIENTS
ORAL UNIT DOSAGE FORMS have accurately measured
amount of medicaments in a single dosage unit
 Easily handled by the patient.
 Major oral unit dosage forms are tablets and capsules.
ADVANTAGES OF ORAL UNIT DOSAGE FORMS:
 Accurate release
 Release characteristics of drug can be controlled
 Uniform product
 Stable & attractive product
 Easy to administer
 Unpleasant tastes can be masked
 Simple to pack, Convenient to carry
DISADVANTAGES OF ORAL UNIT DOSAGE FORMS:
 Difficult to swallow
 Unsuitable for the young
 Excipients may produce unwanted effects
 Release characteristics may not be ideal
DISPENSING OF TABLETS:
 Mostly packaged by manufacturer into unit packs
suitable to issue to the patient with out re-packing by
the pharmacist.
 Role of pharmacist in dispensing of these tablets
SUPPLY OF TABLETS FROM BULK PACK:
 Required number of tablets must be counted from the
bulk container.
 Tablets must remain untouched by hands.
 Cross contamination of different tablets must not occur.
 Counting devices must be cleaned after each usage.
CONTAINERS FOR TABLETS
SPECIAL LABELS FOR TABLETS AND ADVICE FOR
PATIENTS:
CAPSULES:
 These are dosage forms in which the medicaments are enclosed
within a hard or soft gelatin shell.
 Soft gelatin capsules
 Hard gelatin capsules
 Hard gelatin capsules are available in a range of sizes.
 Approximate capacities of hard gelatin capsule shells, based on
lactose:
Cap.
000 00 0 1 2 3 4 5
Content 950 650 450 300 250 200 150 100
ADVANTAGES OF HARD GELATIN CAPSULE:
 Mask unpleasant taste.
 Easy to swallow.
 Require fewer excipients and can be made light resistant.
 Give rapid & uniform release of medicaments.

FORMULATION OF CAPSULES:
 COMPOUNDING OF CAPSULES:
 Hand filling of hard gelatin capsules is rarely carried
out in a community pharmacy but can be done in
hospital pharmacy.
 Two methods are suggested:
 (a)filling from a powder mass
 (b)filling with weighed aliquots
 SHELF LIFE OF CAPSULES
 CONTAINERS FOR CAPSULES AND ADVICE
FOR PATIENTS

OTHER PRODUCTS IN CAPSULE SHELLS:
1. INSUFFLATIONS:
 They are fine powders prepared for inhalation from
a suitable insufflators.
 EYE OINTMENTS AND RECTAL OR VAGINAL
DOSAGE FORMS:

REFERENCES:
 Pharmaceutical Practice by D M Collett and M E
Aulton.
 Solutions - Pg: 87
 Suspensions - Pg: 99
 Emulsions/Creams - Pg: 109
 Ointments, pastes, gels - Pg: 125
 Suppositories and pessaries - Pg: 135
 Powders and granules - Pg: 145
 oral unit dosage forms - Pg: 151

EXTRA REFERENCES:
 COOPER & GUNN’S, DISPENSING FOR
PHARM. STUDENTS BY S. J. CARTER-12TH
EDITION.
 Dispensed preparations - Pg: 8
 Solutions - Pg: 67
 Suspensions - Pg: 100
 Emulsions/Creams - Pg: 120
 Powders and oral unit dosage forms - Pg: 168
 Ointments, pastes, jellies - Pg: 192
 Suppositories and pessaries - Pg: 232
