For First Year B.Pharmacy Students

1. Matoshri Education Society’s
Matoshri Institute of Pharmacy,
Dhanore, Tal- Yeola, Dist- Nashik,423401
Liquid Dosage Form
Prepared by-
Prof. Pawan S. Avhad (M.Pharm)
Prof. Sayali S. Pawar (M.Pharm)

2. Contents
Definition-
 Classification of Liquid Dosage form
 Monophsic Liquid Dosage Form
 Example – Gargles, Mouthwash, Throat Paint,
Eardrop, Enema ,Syrup, Elixir, Lotion.
 Biphasic Liquid Dosage Form
 Suspension
 Emulsion
 Evaluation
 Stability
 Method to Overcome

3. Definition-
- Liquid state forms are meant for internal, parental or external use.
- They are available in monophasic and biphasic forms.
-Monophasic liquid dosage forms are true or colloidal solution.
- Solution is liquid preparation that conations one or more soluble
chemical substance dissolve in specified solvent.( Solute dissolve
in solvent)
-Water is mainly used as a solvent for majority of monophasic
liquid dosage forms.
-The liquid which consists of two phases are known as biphasic
liquids.

4. Advantages
Sweet in Taste
Easy & Faster Absorption
Convenient & Palatable for
Pediatric Patients
Easy for color, flavor
Disadvantages
 Less Accuracy as compare
with Tablet and Injectables
 Heavy for transportation
 Stability Issues
 Bulky & Heavy

6. Gargles-
-Aqueous solution containing antiseptic & antibiotics used to treat
throat infection .
- They are available in concentrated form with direction to dilute
with warm water before its use.
e.g.- Povidone Iodine Gargles

7. Mouthwashes-
-These are aqueous solutions with pleasant taste and odor use to
clean and deodorize the buccal cavity, also has antiseptic and
astringent activity.
e.g.- Listerine Mouth Wash

8. Throat Paint-
-It is viscous liquid Preparation used for mouth and throat infection
e.g.- Phenol Glycerin Throat Paint

9. Mixtures-
-It is liquid Preparation used for oral use.
-Medicament or medicaments are dissolve or suspended in suitable
vehicle
Types
1. Simple mixture containing soluble substance
2. Mixture containing diffusible solids
3. Mixture containing in diffusible solids
4. Mixture containing precipitate forming liquid.
5. Mixture containing Slightly soluble liquid.
Formulation- Water, Aromatic Water, Medicated Vehicle, Chemical
Stabilizer, colouring agent, flavouring agent, preservative.

10. Syrups-
-It is concentrated or nearly saturated solution of sucrose in purified
water .
-Concentration of Sugar is 66.7 %
Formulation- Vehicle e.g. Water,
Chemical Stabilizer e.g. Glycerin, Sorbitol,
Propylene glycol.
Colouring agent e.g. coal tar dyes.
Flavouring agent e.g. Tincture, Essence, Juices.
Preservative e.g. Not needed, but some times parabens
are use and sodium benzoate.

11. Elixirs-
-Clear, sweetened, aromatic, hydro alcoholic liquids intended
for oral use.
-Main ingredient ethyl alcohol (5-40%) water, glycerin, propylene
glycol, flavouring agent
Formulation- Vehicle e.g. Water, alcohol, glycerin, sorbitol, propylene
glycol.
Chemical Stabilizer used as per need.
Colouring agent e.g. coal tar dyes.
Flavouring agent e.g. Black current syrup, raspberry syrup, lemon
syrup.
Preservative e.g. 20% or more alcohol, glycerol or propylene glycol.

12. Linctuses-
-Viscous liquid use to relief from cough.
-Contains medicament having demulcent, sedative or expectorant
action. Should taken in small dose and sipped and swallowed without
diluting with water.
Formulation-
Vehicle e.g. Simple syrup, syrup tolu preferred because of its aromatic
odour.
Chemical Stabilizer used as per need.
Colouring agent e.g. coal tar dyes & Compound tartrazine solution is
most popular.
Flavouring agent e.g. Black current syrup, lemon syrup, benzaldehyde
spirit.( almond like flavor)
Preservative e.g. Syrup itself act as preservative.

13. Ear Drop-
-These are solution of drop which are instilled into ear
-with a dropper.
- It is generally prepared in water , glycerin and propylene
-glycol.
- Used for cleaning ear, softening wax and treating mild
- infection.e.g. Ofloxacin ear drop.
Nasal Drop-
- These are aqueous solution of drops which are
instilled into the nose with dropper .
- Should be isotonic with 0.9 % NaCl with PH and
viscosity similar to nasal secretions.
- Oily vehicle should never use because it produce
lipoid pneumonia.
- Nasal preparation must not interfere with the cleansing action of
epithelial cilia of nasal mucosa. e.g. Otrivine Nasal Drop

14. LIQUIDS APPLIED TO THE SKIN
Lotion-
-It is liquid preparation applied to skin surface without friction.
- Apply with the help of absorbent material such as cotton.
- Used for local action and produce cooling , soothing or protective
purpose. E.g. Calamine Lotion.
Liniments-
-It is liquid or semi liquid preparation meant for
application to skin, applied with friction and rubbing.
- Alcohol is used to increase penetration of
medicament .
-Arachis oil is used because it has good
-spredability .
-It should not apply to broken skin because
it produces irritation to skin
-e.g. Liniment for Joints

15. BIPHASIC LIQUID DOSAGE FORM
Suspension & Emulsion
Suspension-
- It is biphasic liquid dosage form in which finely divided particles are
dispersed in liquid or semisolid vehicle.
-Particle size ranging from 0.5 to 5 micron.
- They are given oral or parenteral route.
e.g. Paracetamol suspension IP.
Qualities-
-Should settle slowly and re-disperse easily on shaking.
- Pour readily and remove easily from container.
- Should be Stable and chemically inert.
- Free from large particles.

16. Advantages
Easy to swallow
Insoluble medicaments
are easily swollen
Bulky powders can be
easily given for adsorbent
of toxins or as antacid.
Disadvantages
Require to shake before use
 Less accurate compare with
solution
 Change in temp. can affect
disperse system

17. Classification of Suspension-
- Oral e.g. Paracetamol Suspension
- Parenteral e.g. Amoxycillin Injection
- Ophthalmic e.g. Moxifloxacin eye drop
- External use e.g. Calamine Lotion
-Classification based on Size of Solid Particles:
-Colloidal suspensions(0.1-0.2microns): Suspensions having particle sizes of
suspended solid less than about 0.2 micron in size are called as colloidal
suspensions.
-Coarse suspensions (>0.2microns): Suspensions having particle sizes of
greater than about 0.2 micron in diameter are called as coarse suspensions.
Molecular dispersion (˂1.0 nm):Suspensions are the biphasic colloidal
dispersions of nanosized drug particles stabilized by surfactants.

19. Formulation of Suspension-
-Flocculating Agents-
They reduce surface tension and improve dispersion of solid in liquid and
minimize Flocculation.
e.g. SLS, Tweens, Spans , Carbowaxes

20. Thickening Agents-( Suspending Agent)
They increases the viscosity of liquid phase so that solid particles remain
suspended in it for sufficient long time to measure uniform dose.
e.g. SLS, Tweens, Spans , Carbowaxes
Semisynthetic
Synthetic

21. -Wetting Agents-
-It reduces interfacial tension between solid particle and liquid medium.
-They adsorbed at solid liquid interface in such a way that affinity of the
particles for surrounding medium is increased and interparticular forces are
decreased .
-e.g. Alcohol
-Preservatives-
-To Protect preparation from microorganism. e.g. Benzoic acid, Sodium
benzoate, methyl paraben and propyl paraben.
-Organoleptic additives-
- Colouring agent, Flavouring agent , Perfumes.

22. DLVO Theory
The scientists Deryaguin, Landau, Vervey and Overbeek developed a theory in
the 1940s which dealt with the stability of colloidal systems.
-DVLO theory suggests that, the stability of a colloidal system is determined
by the sum of the Vander Waals attractive (VA) and electrical double layer
repulsive (VR) forces that exist between particles as they approach each other
due to the Brownian motion they are undergoing.
- The Vander waal forces depend on chemical nature and size of particle. The
electrostatic repulsive forces depend on density, surface charge and thickness
of double layer.

23. Stability of Suspension
Physical Stability can be achieved by maintaining the particle in Brownian
motion a)
1.Provide Electric charge on surface of dispersed particle: The like charge on
the particles will prevent these coming closer together and thus maintaining a
Brownian motion.
2. Maintain solvent sheath around the particle: The solvent layer prevent the
particle coming closer and also maintain Brownian motion.

24. Evaluation of Suspension
Sedimentation method.
 Rheological method.
 Electro kinetic method.
Sedimentation volume –
The suspension formulation(50mL)was poured separately into100mL
measuring cylinders and sedimentation volume was read after 1,2,3 and
7days,and there after at weekly intervals for 12 weeks. Triplicate results were
obtained for each formulation. Sedimentation volume was calculated
according to the equation: F = Vu/Vo
Where, F =sedimentation volume , Vu = ultimate height of sediment
Vo=initial height of total suspension.

25. Degree of flocculation (β) –
It is the ratio of the sedimentation volume of the flocculated suspension
,F , to the sedimentation volume of the deflocculated suspension, F∞
ß = F / F∞
ß = (Vu/Vo) flocculated
--------------------------
(Vu/Vo) deflocculated
The minimum value of ß is 1,when flocculated suspension
sedimentation volume is equal to the sedimentation volume of
deflocculated suspension.

26. Rheological method –
-It provide information about Settling behaviors.
-Brookfield viscometer is used to study the viscosity of the suspension -
It is mounted on heli path stand and using T-bar spindle.
- T-bar spindle is made to descend slowly into the suspension and the
dial reading on the viscometer is then a measure of the resistance the
spindle meets at various level.
- This technique also indicates at which level of the suspension the
structure is greater owing to particle agglomeration.
-The dial reading is plotted against the number of turns of the spindle. -
- The better suspension show a lesser rate of increase of dial reading
with spindle turns, i.e. the curve is horizontal for long period.

27. Electrokinetic Method
-Measurement of Zeta-potential using Micro electrophoresis apparatus
& Zeta Plus (Brook haven Instruments Corporation , USA)
- It shows the stability of a disperse system.