Monophasic liquid dosage forms – PHARMACEUTICS II (Dispensing Pharmacy) D. Pharm 2nd year PDF Notes

 Monophasic liquid dosage forms


A monophonic liquid contains only one
phase i.e., solutes which is completely soluble in solvents. Monophasic liquids
are homogenous systems of dosage forms containing either miscible liquids or
solids which are completely soluble in water, intended for internal use or
external use.


Classification/type of Monophasic

1. Monophasic liquid meant for internal use:

Ex: solutions, mixtures, syrups, elixirs, linctus etc.


1. Mixtures:

A mixture is a liquid preparation containing
medicaments meant for internal use. It contains several doses.


I. Mixture containing soluble substances:

Ex: Carminative mixture

HCo3                            Compound tincture
of cardamom

            Aromatic spirit of ammonia         Weak tincture of ginger

            Spirit of chloroform                      Peppermint water              


1. Dissolve the solid substances in
little quantity of vehicle. Ex – NaHCO3 in Peppermint oil.

2. If any foreign particle appears
filter it.

3. Add any liquid ingredient.

4. Volatile liquids are added at the
end just before adjusting the final volume with vehicle.

5. Final volume is adjusted with
remaining vehicle.

Storage: It is stored in a well-closed greenish tinted graduated bottle.

It is used as carminative, NaHCo3 act as antacid.


II. Mixture containing in-diffusible solids

In-diffusible solids are insoluble in
water. So a suitable suspending agent should be included in the formula to
increase the dispersion of insoluble solids. Ex: CaCo3



             Compound powder of tragacanth

             Tincture catechu

             Purified water



Finely powder the
indiffusible solids with diffusible or soluble solids and compound tragacanth
powder in a motor. Measure three quarters of vehicle and add a portion of it
with trituration to form smooth cream.

The content in
the motor is examined for the presence of foreign particle if any that can be
removed with the help of glass rod or passing through muslin cloth in a
measuring cylinder.

Add the liquid
ingredient if any and volume is made up by adding vehicle.

The mixture is
transferred into a bottle. Corked, polished to remove finger marks and

The label should
be mention “shake well before use”

It is stored in a well closed greenish tinted
graduated bottle.


It is used in the treatment of diarrhoeal,
CaCo3 and tincture
catechu acts as anti-diarrhoeal agent. Compound powder of tragacanth acts as
suspending agent.


III. Mixtures containing diffusible solids:

Diffusible substances are slightly or
partially soluble but diffuse uniformly on shaking for enough time to measure
the dose so suspending agent is not necessary in the formulation.



             Light magnesium water carbonate

             Peppermint water

MgCo3 is a diffusible solid while MgSo4 is soluble in water.

1. Finley powder diffusible solid in a
motor with soluble solid if any measure three quarter of the vehicle and pour a
portion of it with trituration to form smooth cream. Then gradually add the
remainder of the vehicle.

Stage II III and IV are similar to
mixture containing in-diffusible solids.


Storage: It is stored in a well closed greenish tinted graduated bottle.
Whole thing is to be taken at a time should be written on the label.


It is used in the treatment of constipation
MgCo3 acts as a saline
purgative, light MgCo3
acts as an antacid and laxative peppermint water acts as flavoured vehicles.


IV. Mixture containing ppt. forming liquids:

Certain liquid preparations contain
resinous matter, when mixed with water, the resin is precipitated which may
adhere to the sides of the bottle or form a clotted precipitate which will not
re-diffuse upon shaking. To prevent this compound tragacanth powder or
tragacanth mucilage are used.


 Formula:              Potassium iodide                                                

                               Tincture lobelia


                               Chloroform water
add up to                               


Mix 20.0ml of
mucilage of tragacanth with equal volume of water.

Measure tincture
lobelia ether and tincture stramonium separately in a dry measure and pour
slowly into the centre of the mucilage with constant stirring.

potassium iodide in water and mix it with above mixture.

Strain the
mixture through muslin piece if foreign particles are present

Add more of
chloroform water to produce the required volume.

Transfer the
mixture into the bottle, cork, label and dispense.


V. Mixture containing slightly soluble

Ex: Paraldehyde mixture: On
shaking the slights soluble liquids with the solutions of other ingredients and
liquids. It readily mixes with them and distributed throughout the liquid for
sufficient time to ensure uniform distribution in each dose.


Formula:       Paraldehyde                              Syrup

                       Liquid extract of
liquorice       Water



Triturate the paraldehyde, liquid extract of liquorice, syrup and water
in a motor. Transfer        to a bottle
and shake well.

It is stored in a well closed container.


Paraldehyde mixture is used to control
convulsions in infants.

          Paraldehyde is used as sedative.

          Liquid extract of liquorice and syrup
act as sweetening agent.

          Water acts as vehicle.


Formulation of mixtures: The following are the additives or excipients which included in
the preparation of mixtures.


Vehicles: Ex:
Water, aromatic water, syrup vehicle.

Medicament: Ex:
CaCo3, MgSo4

Anti oxidants: Ex:
Sodium Meta

Flavours: Ex:
Lemon spirit, Orange syrup.

Preservatives: Ex:
CHCl3, benzoic acid


2. Linctus:

Linctus is sweet viscous liquid
preparations containing medicament meant for internal use. Linctus are commonly
used in the treatment of cough. To obtain the maximum effect, they should be
taken in small doses, sipped and swallowed slowly without addition of water.

Uses: These used in the treatment of cough. These have sedative or
expectorant and demulcent property.

Ex: Codeine linctus B.P.C


3. Draught:

It is a liquid medicament intended for
internal use which consists of one dose only

Container: Narrow mouthed, screw capped, colourless plain bottle.

Use: Used in emergency treatment as emetics in poisoning.

Ex: Ipecac emetic draught, Paraldehyde draught


4. Elixirs:

Elixirs are clear, flavoured sweetened
hydro-alcoholic liquid preparations for oral administration. Elixirs contain
medicament, syrup, glycerol, water, flavouring agent and preservatives. Elixirs
are commonly used as flavoured vehicle. Elixirs may be simple elixirs without
medicament and medicated elixirs.

Ex: Elixir of vitrol

Piperazine citrate

Elixir simple

Terpin hydrate Elixir

Store in dark place

Uses: Used as flavoured vehicle.


5. Syrup:

Syrup are sweet, viscous concentrated
solution of sucrose. The concentration of sucrose in syrup is 66.7%. If
purified water is used alone for preparing syrup, is known as simple syrup,
when the syrup contains some medicinal substance it is known as medicated
syrup. Syrups are used as sweetening agent, flavoured vehicle as demulcent and
as a preservative.

Storage: Syrups should be freshly prepared unless special precautions have
been taken to prevent contamination.

Uses: 1. Act as sweetening agent.

          2. Act as preservative.

          3. They increase the viscosity of the


2. Monophasic liquid meant for
external use:

Ex: Gargles, mouth washes, throat paints, eye drops, eye lotion, ear
drops etc.


1. Mouth washes:

Mouth washes are simple aqueous
intended to clean & deodorize the buccal cavity. Mouth washes used for its
deodorants, rinsing, refreshing & antiseptic action. The vehicle may be
water or combination of water & alcohol. Mouth washes generally contain
astringent & antibacterial. Medicated mouth washes containing astringent
anti-bacterial agents, Protein precipitants or other agents are also used but
they must be used under the supervision of the dentist. A very simple
preparation like compound Nacl mouth wash containing Nacl & NaHCo3 in peppermint water is
commonly used by a normal person. The continuous use may prove harmful.


Narrow mouthed, coloured fluted bottle
closed with plastic screw cap.


1. Dilute it with an equal volume of
warm water before use.

2. Rinse the mouth 3-4 times daily as

Storage: Preserve in a well closed container store in a cool place.


2. Gargles:

Gargles are aqueous clear solutions
used for the treatment of an infection of the throat. Gargles are generally
dispensed in concentrated form. They must be diluted with warm water before
use. Gargles are highly medicated than the mouth washes. Gargles are pleasantly
flavoured & having PH
of 5-9.5.


Gargles are used by forcing the air
from the lungs through the gargles which is in held in the throat. The gargles
are brought into intimate contact with the mucous membrane of the throat &
allowed to remain there for a few moments after which they are thrown out of
the mouth.

Container: Narrow mouthed, colourless fluted bottles & screw capped.

Label: Must be diluted with warm water before use.

Storage: Preserve in a well closed container.

Use: To treat throat infections.


3. Throat paint:

Throat paints are liquid preparations
applied to the mucous membrane of buccal cavity. These are used to treat mouth
& throat infections, throat paints contains antiseptic astringent &
analgesic property.

may contain volatile solvent that evaporates quickly to leave a dry resinous
film of medicaments. Throat paints are more viscous due to high content of
glycerin. These are sticky & adheres to the affected site & prolong the
action of the medicaments.

Container: – Wide mouthed screw capped coloured bottles with brush.

Labeling: – For external use only.

Storage:  -It should be stored in
air tight containers & placed in a cool.



Ear drops are liquid preparations that
are installed in to the ear.  These are
usually solutions or suspension. It contains one or more medicaments that are
dissolved or suspended in a suitable vehicle. 15ml of ear drops should be

Vehicle: – Water, alcohol, glycerine, propylene glycol, hexylene glycol.

Medicaments: – The following medicaments are used in the ear drops, depending
on the purpose. They are

 1. Boric acid

 2. H2O2

 3. Phenol

 4. Chloromphenicol

Container: -Coloured fluted glass bottle with dropper.

Label: – Not to be taken

              Not to be diluted

              For external use only

Storage: -Store in a cool place

Dose:      -3-5 Drops


1. Cleaning the ear

2. Drying weeping surfaces

3. Softening in the wax

4. Treating mild infections


5. Nasal drops:

Nasal drops are usually aqueous
solutions intended for installation into the nostrils by means of dropper. They
are commonly used for their antiseptic, anti-inflammatory, anti-histamine &
local anaesthetic properties.

At one time, oily
preparations containing liquid paraffin or vegetable oils as vehicles were used
to prolong the action of the drug but now the use of oily vehicles in the
preparation of nasal drops is discouraged because on prolong use the oil
retards the capillary action of the nasal mucous or drops of oil may enter the
trachea & cause lipoid pneumonia. Therefore the aqueous vehicle is
advisable for nasal drops.

Fluted coloured glass bottle with plastic screw cap & dropper.

Label: For external use only.

Storage: Store in a cool place.


6. Liniments:

Liniments are solutions or suspensions
or emulsions applied for external application. They are generally applied with
massage. They posses analgesic, rubifacient, counter irritant & stimulating
properties. These are not applied to broken skin. Liniment contain volatile
ingredients so cool storage necessary & keep away from flame 50 ml of
liniment be dispensed.  Two types of
vehicles are used for preparation of liniments. They are alcohol and oils.

Container: Narrow mouthed, coloured fluted bottle with screw capped.

Label: For external use only

           Shake well before use

           Not to be applied to wounds or
broken skin inflammable.

Stored in well – filled well closed, air tight
containers & place in a place.

Use: Counter – irritant, Rubifacient & analgesic.


7. Lotions:

Lotions are liquids suspensions or
dispersion used for external application to the skin. They are applied to the
skin without rubbing. This is applied with the help of cotton wool. Cotton wool
is soaked in the lotion and applied on the affected part. These lotions are
applied on broken skin.  Lotion may be
employed for local cooling, soothing, protecting and moisturizing purpose.
Dermatologists frequently prescribe lotion for antiseptic, anti-inflammatory,
local anaesthetics & anti fungal action.

Container: Fluted bottle, closed with plastic screw cap

Label: For external use only

           Shake well before use

Storage: Preserve in a well in a well-close container.

Use: protective.

Difference between elixirs and syrups:



Elixirs are clear sweetened aromatic
hydro-alcoholic liquid.

Syrups are concentrated or nearly
saturated solution of Sucrose in purified water.

 In elixirs the main ingredient Used as ethyl
alcohol and it is Concentrated is 5.40% w/w.


In syrup the main ingredient used as
sugar and its conc. is 66.7%.


Difference between lotion and liniments:



1. Applied with friction

Applied without friction

2. It is not applied to broken skin

It is applied to broken skin 

3. It is applied with brush

It applied with absorbent material

4. It make contain camphor

It don’t contain camphor

5. It act as counter – irritant and

It act as anti – septic, anti –
inflammatory and cooling effect 


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