This document discusses formulation development of semisolid dosage forms. It begins by defining semisolid dosage forms as dermatological preparations intended for external application on the skin to produce local or systemic effects. Examples include ointments, creams, pastes and gels. Ideal properties of semisolids are discussed relating to physical, application and physiological characteristics. Common semisolid bases and preparation methods are outlined. Equipment used in the production of semisolids like homogenizers and colloidal mills are also described.

1. F O R M U L A T I O N D E V E L O P M E N T O F S E M I S O L I D D O S A G E
F O R M S
PRESENTED BY:
Thet-ul-wafa Maqsood
Baqai institute of pharmaceutical Sciences
Baqai medical university

2. SEMISOLID DOSAGE
FORMS
The SEMISOLID DOSAGE FORMS includes
Creams
Ointments
Pastes
Gels

3. SEMISOLID DOSAGE
FORMS
 Definition:
Semisolid dosage forms are dermatological preparations
intended to apply externally on the skin to produce local or
systemic effect.
Ex: Ointments, creams, pastes, gels etc

4. SEMISOLID DOSAGE
FORMS
 IDEAL PROPERTIES OF SEMISOLIDS:
o PHYSICAL PROPERTIES
o APPLICATION PROPERTIES
o PHYSIOLOGICAL PROPERTIES

5. SEMISOLID DOSAGE
FORMS
 PHYSICAL PROPERTIES
o Smooth texture
o Non dehydrating
o Non gritty and non greasy
o Elegant in appearance

6. SEMISOLID DOSAGE
FORMS
 PHYSIOLOGICAL PROPERTIES
o Non irritating
o Do not alter membrane or skin
functioning
o Miscible with skin secretion

7. SEMISOLID DOSAGE
FORMS
 APPLICATION PROPERTIES:
o Easily applicable with efficient
drug release.
o High aqueous wash ability.

8. SEMISOLID DOSAGE
FORMS
 Types of semisolid bases:
The ointment base is the substance or part of ointment, which
serves as carrier or vehicle for the medicament. bases are of
following types.

9. SEMISOLID DOSAGE
FORMS
A) Oleaginous bases or Hydrocarbon base
Ex. Hard paraffin, Yellow soft paraffin.
B) Absorbent base
Ex. Hydrous wool fat, lanolin
C) Emulsion bases or water miscible bases
D) Water soluble bases
Ex. PEG, Polysorbate

10. SEMISOLID DOSAGE
 PREPARATION OF SEMI SOLIDS
Trituration
method
Ex. Ointments
creams
pastes
Fusion method
Chemical
reaction method
Emulsification
method
Ex. Ointments
creams
pastes
Ex. Ointments
creams Ex. Ointments
creams
FORMS

11. SEMISOLID DOSAGE
FORMS
 Equipments used are:
o Homogenizer
o Collide Mill
o Filling equipment
o Packaging operation.

12. SEMISOLID DOSAGE
FORMS
 HOMOGENIZERS:
For homogenization colloidal mill is
used.
Colloidal mill:
It consists of two steel discs one is
stationary and other is rotating.when
the material is passed through these
discs they get sheared. Thus,coarse
particles are broken down to small
particles due to shear.
Uses:
Used for preparation of
suspensions,ointments.
Advantage :
It can be easily sterilised.
Disadvantage:
Heat is generated during milling.

13. SEMISOLID DOSAGE
FORMS
Fusion method:
Anhydrous ointments are prepared by fusion
method.
Active substances is dissolved in the melted fats
and waxes and then mixed with base. The melted
mass must mixed while cooling because the fatty
alcohols, fatty acids, and waxes do not form true
solutions, but crystallize from the melt as the
temperature falls.

14. SEMISOLID DOSAGE
FORMS
Homogenization frequently increases the consistency of a
semisolid emulsion because it increases the number of emulsified
particles.
consistency is affected by
1. Number of passes through the homogenizer.
2. Pressures used for homogenization.

15. SEMISOLID DOSAGE
FORMS
 Aeration should be avoided, since it may lead to emulsion instability
and variation in density.
 Aeration maybe prevented at the primary emulsion step if one phase
is introduced into the other in such a manner that splashing and
streaming are avoided.
 Splashing can overcome by careful adjustment of the mixing
conditions and liquid flow pattern.
 Completely enclosed kettles are available for the manufacturing of
semisolids which tend to aerate excessively.

16. SEMISOLID DOSAGE
FORMS
 Manufacture of emulsified semisolids:
 Time, temperature and mechanical work are the three variables in the
manufacture of emulsified semisolids. The three factors are interrelated and must
be carefully controlled if the same high quality batches are to manufactured.
 Equipment is available for automatically controlling many aspects of
emulsion manufacture, such as the complete control of the temperature in the jacket
and regulation of the mixing time and rate of agitation

17. PREPARATION OF
OIL AND
AQUEOUS PHASES

18. PREPARATION
(Oil Phase)
 The components of the oil mixtures are placed into a stainless steel
steam jacketed kettle, melted and mixed.
 Some of the solid components e.g. stearic acid, cetyl alchol are
available in many different forms like cakes, flakes or powder. The
flakes are more preferable because of the convenience of handling.
 Petrolatum (a Hydrocarbon base) is inconvenient to handle unless it
is melted and transferred by pumping or pouring from its drum.

19. PREPARATION
 The oil phase is then strained through several layers of
cheese cloth to remove any foreign matter.
 If petrolatum is used as oil phase then it should be passed
through filter medium particularly in ophthalmic
preparations.
 The oil phase is transferred by gravity or pump to the
emulsion mixing kettle.

20. PREPARATION
 (Aquous Phase)
 The components of the aqueous phase are dissolved in the
purified water and filtered.
 A soluble drug may be added to this aqueous phase.

21. MIXING
OF
PHASES

22. MIXING
 The phases are usually mixed at a temperature of 70 to
720C,because at this temperature intimate mixing of the liquid
phases can occur.
 The properties of some emulsions depend on the temperature at
which the phases are mixed. The initial mixing temperature must
be raised above 70 to 72 0C.

23. MIXING
Equipments used for mixing of phases:
 Agitator mixers :
Sigma mixer and planetary mixer.
 Shear mixers:
Triple roller mill and Colloidal mill.

24. COOLING
COOLING THE SEMISOLID EMULSION:
 The rate of cooling is generally slow to allow for adequate mixing
while the emulsion is still liquid.
 The temperature of the cooling medium in the equipment should
be decreased gradually and at a rate consistent with the mixing of
the emulsion and scrapping of the kettle walls to prevent formation
of congealed masses of the ointment or cream.

25. GELS
Includes in semi solid preparation but It is normally formulated as a suspension.

26. WHAT IS GEL?
 Pharmaceutical gels are semisolid systems in which there is interaction (either
physical or covalent) between colloidal particles within a liquid vehicle.
OR
 A 3D matrics system In which the Active Pharmaceutical Ingredient is invaded.
The vehicle may be:
 Aqueous
 Hydroalcoholic
 Alcohol based Or
 Non Aqueous

27. PHARMACEUTICAL CONS IDERATION OF
PHARMACEUTICAL GELS
Includes:
 Choice of vehicles
 Inclusion of buffers
 Preservatives
 Antioxidants
 Flavoring and coloring agents

28. GELLING AGENT
 These are substances which, when added to an aqueous mixture,
increase its viscosity without substantially modifying its other properties,
such as taste. They provide body, increase stability, and improve
suspension of added ingredient.
Ex. Ethylcellulose , hydroxypropyl cellulose etc.

29. GELLING AGENT
3 types of Gelling Agents:
1. Natural Polymers
 Tragacanth
 Geletin
2. Semi synthetic Polymers
 Carboxymethylcellulose.
 Methylcellulose.
3. Synthetic Polymers
 Carbomer.

30. 1 . NATURAL POLYMERS
Tragacanth Geletin
• Obtained from Collagin (in
plants).
• Biocompatable .
• Can be used in parentrales.
• Should be soaked over
night.
• Forms clumps in water.
• Glycerin and propylene
glycol should be used as a
humectant.

31. 2 . SEMI SYNTHETIC POLYMERS
 Carboxymethylcellulose.  Methylcellulose.
 Used in the conc. Of 4-6%
 Insoluble in water.
 Also use as viscosity Enhancers.
 Used in the conc. Of 5%
 Ethylene and propylene glycol
should be used as a humectant.

32. 3 . SYNTHETIC POLYMERS
An acrylic based polymer.
Used in the conc. Of 0.5-1%
Also used as thickning and suspending agent.

33. GELLING AGENT

34. PREPARATION OF GELS
Water
Preser
vative
• Gelling
agent
Soake
Over
night
Add
Glycerine
With
propylene
glycol
mixed with
API
And then
make up
the
volume

35. DURATION OF SWELLING
A swelling duration of about 24 – 48 hours generally helps in
obtaining homogeneous gels.
Natural gums need about 24 hours.
cellulose polymers require about 48 hours for complete
hydration.

36. A person who Never made a mistake never tried any thing
new…
“Albert Einstein”
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