Pharmacopoeieal Preparations
Syllabus:
Principles and methods of preparation of aromatic waters,
spirits, elixirs, glycerin, linctus, solutions, milk and magmas, mucilages and
special preparations like pyroxylins and flexible collodions.
Reference Books:
1. Cooper
& Gunn’s Dispensing for Pharmaceutical Students by S.J. Carter.
2. Dispensing
Pharmacy by R.M. Mehta
3. Pharmaceutics-II
by R.M. Mehta
4. Pharmaceutics-II
by A.K. Gupta
5. Indian
Pharmacopoeia, 2nd Edn. 1966
AROMATIC WATERS
Definition:
Aromatic waters are clear,
saturated solutions of aromatic substances (may be volatile oils or volatile
solids) in water. Their flavors and taste are similar to the corresponding
aromatic substances used.
Use:
(i)
They are mainly used as the vehicle for oral
liquid preparations due to their flavoring properties. E.g. Peppermint
Water IP.
(ii)
Some aromatic waters have preservative action,
hence are used as menstruum to extract crude drugs. E.g. Chloroform Water IP.
(iii) Some
aromatic waters have mild therapeutic action. E.g. Camphor Water IP has
carminative action, Anise Water has carminative and mild expectorant action.
Methods of Preparations
(a) Solution
method
(i)
The volatile oil is shaken with 500 times its volume of
Purified Water IP.
(ii)
The mixture is shaken for a period of 30 minutes.
(iii) The
mixture is set aside for 12 hours or overnight.
(iv) Filtered.
(b) Using
distributing agents
(i)
The volatile oil is triturated with a sufficient
quantity of powdered talc or kieselghur, or pulped filter paper in a mortar.
(ii)
Purified Water IP 500 times the volume of oil is taken
and mixed.
(iii) The
solution is filtered.
N.B. Talc, kieselghur, pulp of filter paper are
called distributing agents. The volatile oils get adsorbed on the particle
surface and a large surface area helps in quick dissolution of the oil into
water.
(c) Dilution
from cnocentrated preparations
(i)
A concentrated aromatic water is prepared as per the
formula given in the pharmacopoeia.
(ii)
One ml of concentrated aromatic water is diluted with
39 ml of Purified Water IP and mixed.
Examples of various Aromatic Waters
Name of Aromatic Water
|
Name of Concentrated
Aromatic Water
|
Dilution
|
Use
|
|
Conc. Arom. Water
|
Purified Water
|
|||
Anise Water
|
Concentrated
Anise Water
|
1ml
|
39ml
|
Flavor,
Carminative, Mild expectorant
|
Camphor Water
|
Concentrated
Camphor Water
|
1ml
|
39ml
|
Flavor,
Carminative, Mild expectorant
|
Caraway Water
|
Concentrated
Caraway Water
|
1ml
|
39ml
|
Flavor,
Carminative
|
Chloroform Water
|
Chloroform
Water Double Strength (DS)
|
1ml
|
39ml
|
Preservative,
Flavor
|
Cinnamon Water
|
Concentrated
Cinnamon Water
|
1ml
|
39ml
|
Flavor,
Carminative
|
Dil Water
|
Concentrated
Dil Water
|
1ml
|
39ml
|
Flavor,
Carminative (particularly for infants in gripe water)
|
Peppermint Water
|
Concentrated
Peppermint Water
|
1ml
|
39ml
|
Flavor,
Carminative, Weak Preservative
|
Formulae of different aromatic waters available in IP 1966
Name of the Aromatic water
|
Formula
|
Method of
preparation
|
Chloroform Water IP66
|
Chloroform 2.5 ml
Purified water upto 1000ml
|
Solution method.
|
Camphor Water IP66
|
Camphor 1gm
Alcohol (90%v/v)
Purified Water 1000ml
|
Camphor is dissolved in alcohol and the alcoholic solution
is added to purified water drop-wise. The mixture is shaken well. N.B. Water
should not be added to the alcoholic solution.
|
Concentrated Peppermint Water BPC
|
Peppermint oil 20ml
Alcohol (90%v/v) 600ml
Purified Water upto 1000ml
|
Peppermint oil is dissolved in alcohol. Purified water is
added in small amount to the alcoholic solution and shaken vigorously.
Suitable amount of talc is dispersed in the solution to adsorb the excess
oils. Finally the solution is filtered.
|
SPIRITS
Definition:
Spirits are alcoholic or hydroalcoholic solutions of
volatile substances. Most are used as flavoring agents but a few have medicinal
value. The active ingredient in the spirit may be a solid, liquid or gas.
Use:
(i) They
are mainly used as flavoring agents. e.g. Lemon spirit, Peppermint Spirit,
Compound Orange Spirit etc.
(ii)
Some spirits are taken internally for their medicinal
value e.g. Aromatic Spirit of Ammonia IP is a respiratory stimulant.
Storage:
Spirits contains volatile substances hence, should be stored
in tight containers and should be stored in a cool place. This prevents the
volatilization of alcohol or the active substances.
Methods of preparation:
(i)
Simple solution method
e.g.
Chloroform Spirit IP
Spirit of Ether IP
|
(ii) Solution with maceration
e.g. Compound
Orange Spirit IP
|
(iii) Distillation
e.g. Aromatic
Spirit of Ammonia IP
|
Examples:
Name of Spirit
|
Formula
|
Method of preparation
|
Chloroform Spirit IP
|
Chloroform 50ml
Alcohol (90%v/v) upto 1000ml
|
Simple solution
|
Spirit of Ether IP
|
Anaesthetic Ether 330ml
Alcohol (90%v/v) up to 1000ml
|
Simple solution
|
Aromatic Spirit of Ammonia
Synonym. Aromat. Sp. Ammon., Spirit of Sal Volatile
Formula: Ammonium bicarbonate [NH4HCO3] 25g
Ammonia
solution strong 70ml
Lemon
oil 5ml
Nutmeg
oil 3ml
Alcohol
(90%v/v) 750ml
Purified
Water q.s. 1000ml
Method of preparation:
(i) Lemon
oil (5ml) + Nutmeg oil (3ml) + Alcohol 90% (750ml) + Purified Water (375ml) ®
taken in a still (1173ml)
(ii) The
first 875ml portion of the distillate is collected.
(iii) The second 35ml
portion of the distillate is collected separately.
(iv) The second
distillate is taken in a bottle, ammoniumbicarbonate (25g) and strong ammonia
solution (70ml) is taken. The bottle is closed and warmed gently at 600C
on a water bath. The bottle is shaken to dissolve the salt completely.
(v) The
solution is cooled and filtered through cotton wool.
(vi) This
solution is then mixed gradually with the first distillate (i.e. 875ml).
(vii)
Sufficient purified water is added to make up the
volume up to 1000ml.
Storage:
The preparation contains volatile
oils (Nutmeg and Lemon oil) therefore, it should be stored in a tightly closed
container in a cool place.
N.B.
·
Nutmeg oil contains both volatile oil and
non-volatile resinous substances. This resinous matter makes the solution dark
during storage. Hence, by distillation method only the volatile part is
separated out.
Nutmeg oil contains both volatile oil and
non-volatile resinous substances. This resinous matter makes the solution dark
during storage. Hence, by distillation method only the volatile part is
separated out.
·
First distillate contains mainly alcohol and the aromatic part of the
volatile oils. Since it contains the volatile parts hence, it is not heated.
·
The second distillate mainly contains water. Ammonium bicarbonate is
not soluble in alcohol so it is dissolved in the second distillate (aqueous).
·
Ammonium carbonate decomposes in water to produce NH3, CO2
and H2O. To reduce this decomposition strong ammonia solution is
added.
TINCTURES
Definition:
Tinctures are alcoholic or
hydroalcoholic solutions usually containing dilute concentration of active
principles of vegetable or animal drugs.
Methods
of preparation: They are commonly
prepared by maceration or by percolation process.
N.B. Most tinctures of vegetable drugs represents
the extractive from 20g of the drug in 100ml of tincture.
Examples:
Name of the preparation
|
Uses
|
Reference IP 1966 (page no.)
|
Aconite Tincture IP
Belladonna Tincture IP
Capsicum Tincture IP
Compound Cardamom Tincture IP
Compound Cinchona Tincture IP
Datura Tincture IP
Digitalis Tincture IP
Strong Ginger Tincture IP
Hyoscyamus Tincture IP
Ipecacuanha Tincture IP
Nux Vomica Tincture IP
Opium Tincture IP
Camphorated Opium Tincture IP
Orange Tincture IP
Compound Picrorhiza Tincture IP
Stramonium Tincture IP
Urginea Tincture IP
Valerian Ammoniated Tincture IP
|
Analgesic, cardiac depressant
Parasympatholytic
Carminative
Carminative
Antimalarial
Parasympatholytic
Cardiotonic
Carminative
Parasympatholytic
Expectorant and Emetic
Bitter stomachic
Hypnotic, sedative
Hypnotic, sedative
Flavoring Agent
Bitter stomachic
Parasympatholytic
Cardiotonic, expectorant
Sedative
|
93
147
155
189
226
239
315
343
374
444
503
504
505
565
699
787
792
|
ELIXIRS
Definition:
Elixirs are clear, liquid, oral
preparations of potent drugs (like antibiotics, antihistaminics, sedatives
etc.) or unpalatable drugs. They are pleasantly flavoured and usually
attractively colored.
N.B. Elixirs are clear preparations, but mixtures
are often not clear due to the presence of fine droplets of volatile oils
present in it.
Examples:
Name of the preparation
|
Uses
|
Reference IP 1966 (page no.)
|
Elixir of Vitriol IP
Piperazine Citrate Elixir IP
Simple Elixir IP
Terpin hydrate Elixir IP
|
Pharmaceutical aid
Anthelmintic
Pharmaceutical aid
Expectorant
|
726
568
656
736
|
Formulation:
Vehicles
Vehicle is the main part of the
preparation that carries the drug.
·
Production
of a clear solution: Flavoring agents containing essential oils or
precipitates from plant extract may produce faint cloudiness. To keep the
essential oils in solution state 10 – 20% of alcohol is added. Glycerol
(i.e. glycerin) is added to keep the essential oil in to solution and to
dissolve some ingredients of plant extracts like tannins and their oxidation
products.
·
Solution
of medicament of low water solubility: If the drug is not completely
soluble in water then a mixed solvent is used to dissolve the drug (i.e.
medicament). E.g. phenobarbitone is dissolved in alcohol, glycerol and water,
paracetamol is dissolved in alcohol, propylene glycol and glycerol.
N.B. Alcohol is avoided in paediatric elixirs hence
in paediatric Paracetamol Elixir propylene glycol is used as the main solvent.
·
Production
of a palatable preparation: The vehicle of many elixir is syrup or a
flavored syrup.
Adjuncts
Chemical
Stabilizers: Some special chemicals are required to make the elixir stable.
e.g. Citirc acid,
disodium edetate etc.
Coloring
agents: Many elixirs are attractively colored by coal tar dyes.
e.g. Amaranth
(magenta red), Compound Tartrazine (saffron), Green S and Tartrazine (Green).
Flavoring
agents: Sweetening agents and fruit flavors are used.
Sweetening agents:
e.g. Plain and flavored sucrose syrup, glycerol, sorbitol, invert syrup and
saccharin sodium.
Fruit flavor:
Blackcurrant syrup (to mask bitter taste of drug), Raspberry Syrup (to mask
bitter taste of drug), Compound Orange Syrup (to mask sour and bitter taste of
drugs).
Preservatives:
To reduce the mould growth and fermentation preservatives are added.
·
Vehicle containing 20%v/v alcohol, propylene
glycol or glycerol have preservative action.
·
High concentration of syrup has high osmotic
pressure thus acts as preservative.
·
Chloroform Water, Chloroform Spirit have
preservative action.
·
Benzoic acid, methyl parahydroxybenzoate acid
(methyl paraben) or propyl parahydroxynenzoate (propyl paraben) may be used as
additional preservatives.
Example:
Preparation of Piperazine Citrate Elixir
IP
Formula: Piperazine citrate 180g
Chloroform
Spirit 5ml
Glycerin 100ml
Orange
Oil 0.25ml
Syrup 500ml
Purified
water up to 1000ml
Method:
Piperazine citrate is dissolved in small amount of purified water. Orange oil,
glycerin, syrup and chloroform spirit is mixed. Sufficient volume is added to
produce the final volume.
Use:
Anthelmintic.
GLYCERIN
Definition:
These are solutions or medicaments in glycerol with or without water.
e.g. Thymol Glycerin B.P.C.
e.g. Borax Glycerin IP
Formula: Borax 120g
Glycerin 880g
Method: Borax is triturated with glycerol in a mortar. Then the
mixture is warmed with constant stirring to make a clear solution. Filtered if
required.
Use: Bacteriostatic.
e.g. Phenol Glycerin IP
Formula: Phenol 160g
Glycerin 840g
Method: Phenol and glycerin are mixed in a beaker. The beaker is
warmed gently until is becomes a solution.
Use: Local anaesthetic and local
antiseptic. Phenol glycerin is used to prepare Phenol Gargle and Phenol
Glycerin Ear Drop.
Cautions: Phenol Glycerin when diluted
with water becomes caustic so it is diluted with glycerin.
Label: FOR EXTERNAL USE ONLY should be
displayed in the label.
LINCTUSES
Definition:
Linctuses are viscous, liquid, oral preparations that are usually prescribed
for the relief of cough.
Use:
Linctuses are used for treatmentof cough.
Active
ingredients: They contains sedatives and expectorants.
Vehicle:
Syrup IP (67%w/w or
85%w/v sucrose solution) – has sweet taste, has preservative action, viscous.
Glycerol – has
demulcent action, sweet in taste.
Sorbitol – Used in
preparations for diabetic patients, viscous.
Invert Sugar – Sweet
and viscous.
[N.B. Demulcents are inert substances that soothe
inflammed mucous membrane or skin by preventing contact with air/irritants in
the surroundings.]
Adjuncts:
Chemical
stabilizers – Invert sugar has reducing action. This reduces the oxidative
degradation of various colors and flavors. Hence color and flavors of fruit
juices are better preserved in invert syrup.
Coloring agents:
Coal tar dyes e.g. Amaranth – red
color.
e.g.
Compound Tartrazine Solution – yellow color.
Flavoring agents:
e.g. Tolu Syrup
e.g.
Fruit flavors like lemon and blackcurrant
e.g.
Oxymel – has acidic, honey-like sweet taste.
e.g.
Benzaldehyde Spirit – has almond-like flavor.
Preservatives:
Syrup (67%w/w) has high osmotic
pressure hence acts as self-preservative.
Chloroform Spirit
Benzoic acid
solution
Examples
of Linctuses:
(i) Codeine Linctus,
paediatric B.P.C. (ii) Codeine
Linctus, Diabetic
(iii) Diamorphine
Linctus (iv) Compound Tolu
Linctus, Paediatric
Codeine
Linctus, Paediatric B.P.C.
Formula
|
Codeine Phosphate
Lemon Syrup
Benzoic acid solution
Chloroform Spirit
Purified Water
Compound Tartrazine Solution
Syrup, up to
|
3g
200ml
20ml
20ml
20ml
10ml
1000ml
|
Active ingredient (cough
suppressant)
Flavor
Preservative
Preservative
Solvent for codeine phosphate
Color
Vehicle (viscous and sweet)
|
Method
of preparation:
(i) Codeine
phosphate is weighed and taken in a conical flask.
(ii) Water
is added to the flask, heated gently to dissolve.
(iii) Color, benzoic
acid solution and chloroform spirit are added one at a time and mixed
thoroughly after each addition.
(iv) Lemon syrup
is added and mixed. Syrup is added and mixed.
Container:
Codeine phosphate degrades in light so an amber color bottle is used.
Label:
“To be sipped and swallowed slowly
without adding water.”
[N.B. As linctuses are intended to soothe the throat
they should not be diluted or swallowed quickly. To get prolonged contact with
the mucous membrane it must be sipped slowly.]
MILKS
AND MAGMAS
Milks and Magmas are aqueous
suspensions of insoluble, inorganic drugs. Their particles are bigger than the
particles of gel. When prepared they are viscous and because of this there is
no need to add a suspending agent.
Examples: Bentonite Magma USP,
Dihydroxyaluminium
Aminoacetate Magma USP
Milk
of Magnesia USP , Magnesium Hydroxide Mixture BP (Cream of Magnesia)
Milk
of Bismuth USP
Method
of Preparations: There are two methods of preparations
(a) Hydration method and (c) Hydration and Precipitation
method.
(a) Hydration method:
Light magnesium
oxide (MgO) is hydrated with water to produce magnesium hydroxide [Mg (OH)2].
MgO + H2O ® Mg(OH)2.
This method is followed by industries
and in Milk of Magnesia USP.
Disadvantage:
This method produces
highly viscous preparation that is difficult to pour out.
The pH of the
preparation is 10. This produces an alkaline taste that is unpleasant. So 0.1%
citric acid is added to reduce the alkalininty and improve the taste.
Advantage:
Industrially this method is used because this method does not require washing.
(b) Hydration and Precipitation
method:
(i) A
solution of sodium hydroxide (NaOH) is triturated with light magnesium oxide to
form a smooth cream. It is diluted with water.
(ii) The
cream is mixed with a magnesium sulfate (MgSO4) solution while
stirring.
MgSO4 +
2NaOH = Mg(OH)2¯ + Na2CO3.
MgO + H2O = Mg(OH)2¯
(iii) After
some time the magnesium hydroxide will settle. The supernatant liquid is
decanted and the precipitation is washed with purified water. Again the
supernatant liquid is decanted. This process is continued until the preparation
is free from sulfate. [How will you test that the
preparation is sulfate free?]
(iv) The precipitation is mixed
with chloroform water to give the final preparation.
Advantages: (i) The product is neither very viscous nor sediment quickly.
(ii) Produce a
salty taste that is more pleasant than the product obtained from hydration
method alone.
MUCILAGES
Definition:
Mucilages are thick, viscous, adhesive liquids produced by dispersing gum in
water, or by extracting mucilaginous substances from plants with water.
Examples:
Name
of the mucilage
|
Preservative
used
|
Source
|
Indian Gum Mucilage IP
|
Chloroform water
|
Acacia
arabica
|
Acacia Mucilage NF
|
Benzoic acid
|
Acacia
senegal
|
Tragacanth Mucilage BPC
|
Alcohol and Chloroform Water
|
Astragalus
gummifer
|
Starch Mucilage B.P.C.
|
No preservative
|
Starch from maize or wheat
|
Use:
·
Mucilages are used as suspending agents in
suspension preparations to reduce the rate of sedimentation.
·
Acacia mucilage is used as suspending and
emulsifying agents in different preparations taken orally. It is very sticky
hence never used in external preparations.
·
Tragacanth mucilage is more viscous than Acacia
mucilage, hence the former is used to suspend heavy indiffusible powders or
resinous tinctures. It is less sticky than Acacia mucilage so can be used in
external preparations lke jellies, lotion, pastes and creams.
·
It is used with other mucilages for its high
viscosity.
Preparation
of Acacia mucilage
Formula: Acacia, tears (or powder) 40g
Chloroform
Water 60ml
Chloroform Water, 60ml is taken in a
beaker. Acacia powder (or acacia tears) is taken in a muslin cloth and tied as
a bag. The bag is suspended in the beaker without touching the bottom of the
beaker. It is left for 2 to 3 days until the solution is complete. The final
product is gently stirred.
Preparation
of Tragacanth mucilage
Formula: Tragacanth 12.5g –
gum
Alcohol(90%) 25ml – dispersing agent
Chloroform
Water 1000ml – vehicle with preservative action
Alcohol (90%) 20ml is taken in a wide
mouthed bottle. Tragacanth powder is added to it and dispersed. Chloroform
water is added quickly, bottle is closed and shaken vigorously to produce the
solution. Volume is made up with the chloroform water.
Preparation
of Starch Mucilage
Formula: Starch 25g
Purified
Water to 1000ml
Water 200ml is boiled in a conical
flask.
In a mortar starch is triturated with
30ml of cold water.
The suspension is then poured in the
boiling water and shaken. Rest of the water is added and mixed and boiled until
a gelatinized.
Immediately cooled (so that no skin
is formed) by rotating the conical flask under running tap water.
Water is added to make up the volume
up to 1000ml.
N.B. Other synthetic mucilages are
made from methyl cellulose, sodium carboxymethylcellulose, polyvinyl alcohol
etc.
Disadvantages:
·
Acacia mucilage becomes acidic by enzymatic
degradation. Acacia contains an oxidase enzyme that oxidize easily oxidizable
drugs.
·
Tragacanth mucilage thickens on storage.
COLLODIONS
Definition:
Collodions are liquid preparations
for external use. They are applied with a brush. The vehicle is volatile and
evaporates on application to the skin, leaving a flexible, protective film
covering the site.
·
The volatile solvents are ether and alcohol.
·
The film-producing ingredient is pyroxylin (nitrocellulose).
·
The substance giving the flexibility is called plasticizer. Here castor oil acts as
plasticizer.
Classification
of collodions
(i) Unmedicated
Collodion e.g. Flexible Collodion IP. This is useful for protecting small
cuts and abrasions.
(ii) Medicated
Collodion e.g. Salicylic acid collodion BPC contains 12%w/v salicylic acid
in flexible collodion. These are provided for prolonged contact between the
skin and medicament (drug).
Flexible
Collodion IP
Pyroxylin 16g
Colophony 30g
Castor
oil 20g
Alcohol (90%) 240ml
Solvent Ether q.s. 1000ml
Method
of preparation:
(i) Pyroxylin
is immersed in the alcohol (90%v/v) in a bottle.
(ii) Colophony
and the Castor oil are added.
(iii) Suffcient solvent
ether is added.
(iv) The bottle
is closed and shaken and allowed to stand for a few days, while impurities
settle and then the supernatant solution is decanted.
N.B.
Pyroxylin is a nitrated cellulose obtained by treating
defatted cotton with a mixture of nitric and sulfuric acid. Its principal
constituent is cellulose tetranitrate.
It is highly inflammable, so it is kept moist with
methylated spirit and stored loosely packed, in a well-closed container,
protected from light and in a cool place. Before use it is allowed to dry in
air.
Collophony / Rosin: It is pale-yellow or brownish yellow
glass-like solid residue left after distilling volatile oil from the oleoresin
obtained from species of pinus. It is used for its adhesive quality.
Storage
·
Air tight container is used to reduce the
evaporation of organic solvents.
·
Smaller bottles (5ml) are used because from
larger bottle the loss of solvent is higher whenever the cap is removed.
·
The cap is fitted with a brush, or glass rod or
a plastic applicator.
·
The bottle should be amber colored and fluted.
N.B. Fluted bottles are used for
external preparations.
Label:
‘For
external use only’
‘Store
in a cool place’
‘Highly
inflammable, keep away from naked flame.’
Questions
for Test-I
Q1. What do you mean by: [2]
(i)
Aromatic waters (ii) Spirits (iii) Elixirs (iv) Glycerin (v)
Linctus
(vi)
Milks & Magmas (vii) Mucilages (viii) Collodions
Ans. Give the definition, main features and uses of each dosage
form. Do not give the preparation, storage or instructions.
Q2. Describe the method of
preparation of : [3]
(i) Camphor Water IP (ii)
Concentrated Peppermint Water IP
(iii) Chloroform Spirit IP (iv) Piperazine Citrate
Elixir IP
(v) Borax Glycerin IP (vi)
Codeine Phosphate Linctus Paediatric IP
(vii) Milk of Magnesia (viii)
Flexible Collodion
Q3. Give examples of pharmacopoeial
preparations of
(i) Aromatic waters (ii) Spirits (iii) Elixirs (iv)
Glycerin (v) Linctus
(vi)
Milks & Magmas (vii) Mucilages (viii) Collodions – Ans. Give only the names not formulas.