Dosages Forms can be classified into:
Liquid Dosage Forms
Solution Syrup
Suspension Emulsion


LIQUID DOSAGE FORMS
1. SOLUTIONS:
A group of preparations in which the molecules
of the solute (the dissolved substance) are
dispersed among those of the solvent.
Solutions can be classified into:
1- Aqueous solutions
2- Sweet and/or viscid solutions
3- Non-aqueous solutions

1- Aqueous Solutions
Definition: Are liquid preparations that contain one or more
soluble chemical substances dissolved in water.
Advantages: It is
Tasteless
Odorless
Free from irritating qualities
Pharmacologically active

Aromatic Waters: (medicated waters)
Clear, saturated aqueous solutions of volatile oils or other
aromatic or volatile substances.
Used principally as flavored or perfumed vehicles.
Examples of aromatic waters:
* Peppermint Water USP
*Stronger Rose Water USP

1- Douches:
 Aqueous solutions directed against a part or into a
cavity of the body
 Are used as cleansing or antiseptic agents such as
eye douches.
2- Enemas:
 Rectal injections employed to evacuate the bowel.
 They may possess anthelmintic, nutritive, sedative,
or stimulating properties.
Examples of aqueous solution preparation:

Gargles:
Aqueous solutions frequently containing
antiseptics, antibiotics, and/or anesthetics
Are used for treating the pharynx and
nasopharynx (gargle is expectorated).
Mouthwashes:
Aqueous solutions containing for example
antibiotics and flavoring agents to reduce plaque,
gingivitis, dental caries, or to reduce bad breath.

Nasal solutions:
Aqueous solutions designed to be administered
to the nasal passages in drops or sprays.
 Are used to produce a local effect such as to
reduce nasal congestion or to produce a systemic
effect in many diseases.
Otic solutions:
Aqueous solutions used for topical administration in
ear.
Irrigation solutions:
Used to wash surgical incisions, wounds, or body
tissues.

2- Sweet and/or Viscid Solutions:
Syrups
Are concentrated solutions of sugar such as
sucrose in water or other aqueous liquid.
 Syrup NF contains:
850 g of sucrose + sufficient purified water
(450 ml) to make 1 L of syrup,
It is not saturated.
 It is an 85% weight-in-volume (w/v) or
approximately 65% weight-in-weight (w/w)
solution with a specific gravity of 1.30.


3- Non-aqueous Solutions
A) Elixirs
 Are clear, pleasantly flavored, sweetened
hydroalcoholic liquids intended for oral use.
 The main ingredients in elixirs are ethanol and
water but they usually include syrups,
glycerin, flavoring agents and preservatives.
 They are used as flavors or as medicated
elixirs.

B) Spirits
 Spirits known as essences, are alcoholic,
hydroalcoholic solutions of volatile substances
containing 50%-90% alcohol.
 This high alcoholic content maintains the
water-insoluble volatile oils in solution.
 If water is added to a spirit, the oils separate.
3- Non-aqueous Solutions

3- Non-aqueous Solutions
C) Glycerins
 Glycerins or glycerites are solutions or
mixtures of medicinal substances is not
less than 50% by weight of glycerin.
 Glycerin is a valuable pharmaceutical
solvent forming permanent and
concentrated solutions not otherwise
obtainable.

2. SUSPENSIONS
 Suspension is a two-phase system consisting of a
finely divided solid dispersed in a liquid.
 The particle size of the dispersed solid is usually
greater than 0.5 m, the liquid can be oily or aqueous.
Preparations of suspensions are:
 Oral mixtures, parenteral preparations and ophthalmic
preparations.
 Insoluble drugs may be formulated as suspensions for
topical use such as calamine lotion.

Properties of suspensions:
 In well formulated suspensions the
dispersed solid should settle slowly, if at all,
and be redispersed readily on shaking.
 The particles should have similar sizes and
should not cake on settling.
 The viscosity should be such that the
preparation pours easily.

The main ingredients in a suspension
 The drug
 Agents to wet the drug (wetting agents)
 Agents to influence flocculation
(flocculating agent)
 Agents to control viscosity
 External medium, usually water.
In addition, flavoring, sweetening, and
coloring agents and preservatives are
used.

Advantages of Suspensions
1- Used to supply drugs to the patient in a liquid
form which is very convenient for many people.
2- If the drug is insoluble or poorly soluble, a
suspension may be the most suitable dosage
form
3- If a drug is unstable in an aqueous medium.
4- The taste of pharmaceuticals can be generally
improved if they are supplied in suspension
form rather than solutions

3. EMULSIONS
 It is a two-phase system prepared by
combining two immiscible liquids, one of
which is dispersed uniformly throughout the
other.

 The liquid that is dispersed into small
droplets is called the
 Dispersed phase
Internal phase
Discontinuous phase
 The other liquid is the
 Dispersion medium
External phase
Continuous phase

 When oil is the dispersed phase and an
aqueous solution is the continuous phase,
the system is designated as an oil-in-water
(O/W) emulsion.
 Conversely, where water or an aqueous
solution is the dispersed phase and oil or
oleaginous material is the continuous
phase, the system is designated as water-
in-oil (W/O) emulsion.

 Emulsions are unstable because:
The globules of the dispersed liquid
tend to coalesce to form large globules
until all of the dispersed globules have
coalesced.
 An emulsifying agent is usually added
to the system to prevent the
coalescence of the globules and
maintain the integrity of the individual
globules of the dispersed phase.

Advantages of emulsions over other liquid
forms:
1- The unpleasant taste or odor of an oil can be
masked partially or wholly, by emulsification
2- The solubility of many drugs is increased when
they are incorporated into emulsions
3- The stability of many drugs which are unstable
in aqueous solutions is increased when
incorporated into an emulsion