Departmernt of pharmacy
University of karachi
• Ideal properties of semi solid dosage form
• Advantage And Disadvantage
• Method Of Prepration
• Evaluation Of Semi Solid Dosage Form
Semi solid pharmaceutical
system comprise a body of
product ,which when applied to
skin or accessible mucous
membranes tends to allevate or
treat a pathological condition
or other protection against
a) Smooth texture
b) Elegant in
c) Non dehydrating
d) Non gritty
e) Non greasy and non
f) Non hygroscopic
a) Non irritating
b) Do not alter
c) Miscible with skin
a. Easy applicable with efficient drug release
b. High aqueous washibility
Ointments are homogenous, translucent, viscous, semi
solid preparation intended for external application to
skin or mucous membranes. Ointment may be
medicated or not..
Applied to mucous membrane or skin
Applcation for active ingredients to the skin
Viscous semi solid emulsion with opaque appearance
Contrasted with translucent ointments
Consistency depends on whether the cream is W/O
W/O Creams O/W Creams
Used as emollient or as
O/W creams are elegant
drug delivery system
Contains high percentage of insoluble
solid(usually 50% or more)
Pastes are usually prepared by
incorporating solids directly into a
congealed system by levigation with a
portion of base to form paste like mass.
They have good adhesion on skin and
i. Gels are semi solid system in which liquid phase is
ii. With a 3-d polymeric matrix having a high degree
iii. Or chemical cross linking
iv. Gels are aqueous colloidal system of hydrated
forms of insoluble medicaments.
v. Jellies are transparent or translucent non greasy
semisolid and contain more water than gels.
vi. Used for medication,lubrication and carrier for
spermicidal agents to be used intra vaginally with
1. They are solid masses of solid matter applied to skin in
2. Reduce inflammation and in some cases to act as a
3. Poultices must retain heat for a considerable time.
4. After heating the preparation is spread on dressing and
applied to the affected area .
5. E.g: Kaolin poultice (B.P.C)
Plasters are solid or semi solid masses made
by incorporating medicaments in the
resinous or waxy bases which are melted or
spread on suitable baking material..
They are generally used to,
Afford protection and medicinal support.
Furnish on occlusive and mecerating
Bring medication in to close contact with
the surface of skin.
It is solid or stiffened semi solid dosage form intended to insertion
on body orifices where they melt,soften and dissolve
and exert local or systemic effect.
Ingredients used in preparation of semi
solid dosage form:
Active pharmaceutical ingredients
It is one of the most important ingredient used in the
formulation of semisolid dosage form
Ointments and suppository base do not merely acts as the
carrier of the medicaments, but they also control the extent
of absorbtion of medicaments incorporated with them
They should be:
Compatible with skin ph and drug
Inert ,non irritating and non sensitizing
Good solvent and/or emulsifying agent
Emollient , protective , non greasy and easily removable
Release medicaments easily at the site of administration
Pharmaceutical elegant and possess good stability.
Oleaginous ( hydrocarbon)
They consist of a combination of more than one oleaginous material
such as water insoluble hydrophobic oils and fats
They are highly compatible ; occlusive ; good emollients
They are anhydrous, do not absorb water, readily(hydrophobic)
insoluble in water, non washable
Example : Vaseline,hard parafin, liquid paraffin,white ointment.
Uses : protective, emollient and vehicle for solid drugs.
Absorption (Emulsifiable) base:
Have capacity to absorb considerable quantities of water or
aqueous solution and turns to w/o without marked changes in the
They are anhydrous, water insoluble and water unwashable.
They have good emollient but poor occlusive property.
Uses: protective, emollient and vehicle for aqueous solutions and
According to the type of emulsion these bases are classified as
either W/O or O/W.
W/O EMULSION BASE O/W EMULSION BASE
Will absorb water Will absorb water
Insoluble in water Insoluble in water
Not washable washable
Water soluble Bases:
These include both hydrous and non hydrous dermatological non-
emulsion bases which are water soluble and contain no oil phase.
Water soluble, water washable, non greasable
Because they softens with the addition of water, large amount of
aqueous solutions are not effectively incorporated into the bases.
Example : carbowax compounds such as the poly ethylene glycol bases
containing pectin, cellulose, bentonite and gelatin.
Some bases , although, resist microbial attack but because
of their high water content, it require an anti microbial
Commonly used preservative include:
Methyl hydroxy benzoate
Propyl hydroxy benzoate
Phenyl mercuric nitrate
Oxygen is highly reactive atom that is capable of becoming of
potentially damaging molecules commonly called “free radicals”.
Free radicals are capable of attacking the healthy cells of the
body, causing them to loose their structure and functions
To prevent this an anti oxidant are added.
Example : Butylated hydroxy anisole , Butylated hydroxy
Acts by reacting
with the free
(used for oil system)
Have lower redox
(used for aqueous
agents, enhance the
effect of anti
Gelling agent forms a gel dissolves in a liquid phase as a
colloid mixture that forms a weakly cohesive internal
These are organic hydro colloids or hydro phillic inorganic
Example : tragacanth, sodium alginate, pectin, gelatin,
Material % Brook field
Carbomer 94 1 resin NF 0.15 2900
Carbomer 94 1 resin NF 0.25 6300
Guar gum 1.50 8040
Methyl cellulose 2.00 5200
Sodium alginate 2.50 10400
Skin can acts as a barrier with the
introduction of various panetration
enhancers, panetration of the drug through
the skin can be improved.
Permeation enhancer Drug used
Limonene Indomethacin , ketoprofin
Oleic acid Piroxicam
A humectant is a hygroscopic substance . It is
often a molecule with several hydrophilic
groups, most often hydroxl group.
Humectants are used to:
Increase the solubility of active ingredients
To elevate its skin preparation
Elevate the hydration of the skin.
Buffers are added to variopus purpose such as:
Compatibility with skin
Influence on ionization of drug
Example: Sodium acetate , Sodium Citrate , Potassium meta
Water for Injection
Water for injection may be used in
ophthalmic semi solid preparation like eye
ointments , gels etc
MIXING WITH BASE
SPATULATION OR TRITURATION
MIXING BASE TO PRODUCE