The document provides a comprehensive overview of liquid dosage forms in pharmaceuticals, including classifications such as monophasic and biphasic forms, with detailed sections on syrups, suspensions, and emulsions. It discusses the advantages and disadvantages of liquid forms, the pharmaceutical additives used, and methods for enhancing solubility and stability. Additionally, the document outlines the applications of these dosage forms in pharmaceutical, cosmetic, food, and paint industries.

1. LIQUID DOSAGE FORMS
Ruchi Pal
Assistant Professor
Maa Bhagwati College Of
Pharmacy, Lucknow.

2. CONTENT
• Introduction
• Advantages & Disadvantages
• Pharmaceutical Additives used in liquid dosage form
• Classification of Liquid dosages forms
• Monophasic liquid dosage forms
• Biphasic liquid dosage forms
• Pharmaceutical Emulsion
 Introduction
 Classification
 Uses
 Advantages & Disadvantages
 Methods of preparation
• Pharmaceutical Suspension
 Introduction
 Advantages & Disadvantages
 Classification
 Flocculated & Deflocculated suspension
 Evaluation of suspension

3. LIQUID DOSAGE FORM
• Liquid dosage form are liquid in nature & are meant for internal, external or simple meant to
insert into body cavities.
• For example-Solution, Syrup, Elixir, Suspension.

4. • Syrup: A viscous oral liquid that contains one or more active ingredients in
solution. The base generally contains large amounts of sucrose, other sugars, or
sweetening agents. Syrups may contain ethanol (95%) as a preservative or as a
solvent for flavors. Antimicrobial agents may also be added to syrups to maintain
the microbial quality of preparation.
• Oral Suspension: an oral liquid that contains one or more active ingredients
suspended in a suitable base.
• Oral Solution: an oral liquid that contains one or more active ingredients dissolved
in a suitable base.
• Oral Drop: an oral liquid that is prepared to take in small quantity with the help of
a suitable measuring device such as a dropper.
• Oral Emulsion: an oral liquid that contains one or more active ingredients that are
unstable in the water phase and is stabilized oil-in-water dispersions; either or both
phases of the preparation may contain dissolved solids.
• Mixtures: an oral liquid containing one or more active ingredients suspended or
dispersed in a suitable base.
• Linctus: a viscous oral liquid that contains one or more active ingredients dissolved
in a suitable base that generally contains a higher concentration of sucrose or other
sugars.
• Elixir: a clear, flavored oral liquid containing one or more active ingredients
dissolved in a suitable base that contains a high proportion of sucrose and may also
contain ethanol (95%) or a diluted ethanol.

5.  Advantages of liquid dosage form-
• Most convenient dosage form for
infants and childrens.
• Possible to formulate drugs with
bitter odour & taste in liquid dosage
form by addition of sweetning &
flavouring agent.
• Adjustment of dose as per the
requirment, need & nature of patient
is possible.
• Liquid dosage form have good
absorption as compared to solids.
 Disadvantages of liquid
dosage form-
• They are difficult to
handle, carry, store and
transport.
• Liquid dosage form
containing alcohol as
vehicle in various cup
syrup, & may account to
severe toxicity when
administered in children.
• Accuracy of dose is major
issue in case of liquid
dosage form.
• Two incompatible drug
cannot be formulated as
liquid dosage forms.

6. Pharmaceutical Additives/Excipients used in liquid
dosage form

7. • Antioxidants-Vitamin A,C, E, Beta carotene, Lutein, Lycopene
• Solvents- Water, Polyhydric alcohol, Hydro-alcoholic solution etc.
• Surfactants- SLS, Tween, Span
• Preservatives- Benzoic acid, Potassium Nitrate, Sodium Benzoate
• Coloring agents- Turmeric, Safaranin.
• Flavouring agents- Lemon, Mango, Strawberry.
• Sweetning agents- Glucose, Sucrose, Saccharin.
• Solubilizing agents- Glycerine.

8. Methods of Solubility Enhancement
• Solubility- The ability to be dissolved, especially in
water.
• The maximum amount of a substance that will dissolve
in a given amount of solvent at a specified
temperature.
• METHODS-
a) Particle size reduction
b) Surfactant
c) PH adjustment
d) Salt formation
e) Solid dispersion

9. Emulsifying agent(Emulsifier)
• The emulsifying agent is a surface-active substance to make an emulsion,
which is both fat and water-soluble. It helps the dispersed phase to
uniformly dispersed in the continuous phase.
• Examples of Emulsifying agent(Emulsifier):
• Natural Emulsifying Agents: Acacia, Tragacanth, etc.
• Synthetic Emulsifying Agents: Polysorbate 20, Polysorbate 80, Sodium
lauryl sulfate(SLS), Sorbitan laurate, Sorbitan stearate, etc.

10. Pharmaceutical Emulsion
 An emulsion is a two phase system consisting of
two completely immiscible liquids one of which is dispersed as fine globules
into other.
 This thermodynamically unstable system is stabilised by
presence of emulsifying agents.
 There are two phases in an emulsion. One is the dispersed phase and
another is the continuous phase. The concept is a dispersed phase (liquid),
which is dispersed or spread in the other phase(continuous phase).
 Examples of emulsions: Milk (fat in water), Butter (water in oil), Liquid
paraffin (paraffin in water), etc.

12.  Advantages-
 Cover up the unpleasant taste.
 Increase the bioavailability of the dose.
 Sustained release medication.
 Very cost-effective.
 Disadvantages-
 Problem of creaming and sedimentation
 Phase inversion
 problem of handling.

13. Method of Preparation of Emulsion

14. Stability of Emulsion

17. Uses of Emulsion
• Pharmaceutical Application: Due to the high bioavailability
and absorption rate, it used in the pharmaceutical
industry. Mostly it used for topical preparations like creams,
lotions, etc.
• Cosmetic industry: There is a huge application of emulsion in
the cosmetic industry. Example: creams, lotions, hair
conditioners, etc.
• Food industry: Food products like milk, peanut butter, ice
cream, etc. are some examples of emulsion. So you can easily
understand the application of emulsion in this industry.
• Paint industry: Examples like emulsion paints and inks.

18. Pharmaceutical Suspension
• The pharmaceutical suspension is a biphasic liquid or semi-solid dosage
form where the finely divided insoluble solid drug particles are
homogeneously dispersed in a liquid or semi-solid medium.
• The insoluble solid drug particles act as the dispersed phase or internal phase.
 Properties of Suspension
• A suspension is a heterogeneous mixture.
• The size of solute particles in a suspension is quite large.
• The particles of a suspension can be seen easily.
• The particles of a suspension do not pass through a filter paper. So a
suspension can be separated by filtration.
• The suspension is unstable. The particles of a suspension settle down after
some time.
• A suspension scatters a beam of light passing through it because of its large
particle size.

20.  Examples of Suspension
• Muddy water
• Milk of magnesia- Milk of magnesia
is the common name for magnesium hydroxide,
which is a type of saline laxative. It's
recommended for occasional constipation. You
can expect to have a bowel movement within 6
hours of taking milk of magnesia.
• Sand particles suspended in
water
• Flour in water
• Slaked lime for whitewashing
• Paints in which dyes are
suspended in turpentine oil.

21. Classification of Pharmaceutical Suspensions

22. Oral Suspension

23. Externally applied suspension

24. Parenteral Suspension

25. Rectal suspension

26. Flocculated & Non-flocculated
Suspension

27. Evaluation of Stability of Suspension
• Prepared suspension were evaluated by studying different
parameters like
 pH,
 sedimentation volume,
 redispersibility,
 Flow rate (F),
 viscosity,
 Degree of flocculation- A most important parameter in the evaluation stability of the
suspension. Sedimentation volume is a ratio of the ultimate volume of sediment (Vu) to the
original volume of sediment (VO) before settling. The sedimentation volume gives only a
qualitative account of flocculation.
 effect of temperature etc.