Emulsion and cream gp b

1. DOSAGE FORM SCIENCE
LAB ASSIGNMENT
COURSE CODE : PHARM-406
COURSE INSTRUCTOR : TAHMINA MAQBOOL
TOPIC: EMULSION AND CREAM
NAME ROLL NO. CMS ID.
Fareeha Waseem R-022 94-2019
Afreen Shah R-006 58-2019
Muhammad Ahsan R-051 31-2019
Syed Ali Hasnain R-088 44-2019
Saifullah Sheikh R-074 79-2019

2. EMULSIONS

3. EMULSIONS
GENERAL INTRODUCTION
An emulsion is a type of dispersion in
which a liquid phase composed of small
droplets or globules is distributed
homogeneously throughout a liquid
vehicle in which it is immiscible using
an emulsifying agent.
The liquid phase consisting of small droplets is referred to as the dispersed or
internal phase, while the vehicle in which these are dispersed is referred to as the
continuous or external phase.

4. TYPES OF EMULSION
Emulsions can be further classified as:-
 Oil-in-water (O/W)
 Water-in-oil (W/O)
O/W refers to an emulsion with an oleaginous
(i.e. oil) internal phase and an aqueous external phase,
while W/O describes an emulsion with an aqueous
internal phase and an oleaginous external phase.
It is also possible to make more complicated emulsion systems, such as oil-in-
water-in-oil (O/W/O) or water-in-oil-inwater (W/O/W), by re-emulsifying an
existing emulsion within another external phase
An emulsifying agent (emulsifier) is an inactive ingredient that is added to
stabilize the dispersion and prevent two immiscible phases from separating,
Emulsifying agents can be surfactants and polymers.

5. ROUTE OF ADMINISTRATION
Like suspensions, emulsion-based formulations can be developed for
various administration routes, including oral, injection, ophthalmic,
or topical.
Oral Route:
O/W or W/O/W emulsions are used for oral delivery as these
systems allow for the administration of poorly water soluble drugs in
which the drug is dissolved in the oil-based dispersed phase.
Topical Route:
Semisolid emulsions are often preferred for topical application,
Depending on the drug and disease state, W/O emulsions spread
more easily on the skin, while O/W emulsions are more
conveniently removed from the skin. Drugs known to be irritating
may be placed in the internal phase of the emulsion to reduce
irritation.

6. APPLICATION OF EMULSION:
• Emulsions are used in medicines such as emulsion of cod liver oil, malt
and yeast.
• They are used in oil paints, plastic emulsion paints.
• Phenyl, when poured in water, give oil in water emulion. Its used as a
disinfectant.
• Cleaning action of soap or detergent is due to emulsion formation of oil
with water.

7. METHODS OF EMULSION PREPARATION
 Emulsions may be prepared by several methods, depending upon the nature
of the components and the equipment.
 On a small scale , as in the laboratory or pharmacy, emulsions may be
prepared using a dry Wedgwood or porcelain mortar and pestle; a
mechanical blender or mixer.
 On a large scale, large mixing tanks may be used to form the emulsion
through the action of a high-speed impeller.

8.  In the small-scale extemporaneous preparation of emulsions, three methods
may be used.
a) continental or dry gum method.
b) English or wet gum method.
c) Forbes bottle method.
a) Continental or Dry Gum Method:
The continental method is also referred to as the 4:2:1 method because for
every 4 parts by volume of oil, 2 parts of water and 1 part of gum are added in
preparing the initial or primary emulsion. For instance, if 40 mL of oil is to be
emulsified, 20 mL of water and 10 g of gum would be employed in the primary
emulsion, with any additional water or other formulation ingredients added
afterward.
b) English or Wet Gum Method:
By this method, the same proportions of oil, water, and gum are used as in the
continental or dry gum method, but the order of mixing is different, and the
proportion of ingredients may be varied during the preparation of the primary
emulsion as is deemed necessary by the operator. The oil is then added slowly
in portions, and the mixture is triturated to emulsify the oil.Should the mixture
become too thick, additional water may be blended into the mixture before
another portion of oil is added.

9. c)Bottle or Forbes Bottle Method:
The bottle method is useful for the extem poraneous preparation of
emulsions from volatile oils or oleaginous substances of low viscosities.
This method is not suited for viscous oilsbecause they cannot be thoroughly
agitated in the bottle when mixed with the emulsifying agent. When the
intended dispersed phase is a mixture of fixed oil and volatile oil,the dry
gum method is generally employed.

10. EMULSIFYING AGENTS
 An emulsifying agent is typically a surface-active excipient that is adsorbed
around the surface of the internal phase droplets of an emulsion in order to
reduce interfacial tension between the two phases. The emulsifying agent
must not only promote emulsification and stability of the system such that
the two immiscible liquids do not separate, but it must also be compatible
with other emulsion ingredients and not cause adverse effects.

11. TYPES OF EMULSIFYING AGENTS:
 Various types of emulsifying agents may be utilized in pharmaceutical
preparations, including macromolecules, high molecular weight alcohols,
surfactants, and finely divided solid particles.
TYPES OF EMULSIFYING AGENTS:
NATURAL: derived from
plant or animal sources
SYNTHETIC:
Surfactants: move to a
liquid-liquid interface; reduce
surface/interfacial tension of
system Have hydrophilic and
lipophilic portions

12. STABILIZATION THEORY:
Upon mixing of two immiscible liquids, one of the phases will divide into
small droplets. This results in a large increase in interfacial area and,
therefore, interfacial tension of the system. To reduce the interfacial area
between the two immiscible phases, There are several theories regarding
how emulsifying agents promote stability, which include the following:
• SURFACE TENSION THEORY:
The surface tension theory considers that the addition of a
surfactant increases stability of an emulsion through reduction
of the interfacial tension between two immiscible liquid phases.
•PLASTIC OR INTERFACIAL FILM THEORY:
In the plastic or interfacial film theory, it is hypothesized that
the emulsifying agent collects at the interface of the oil and
water liquids, leading to a formation of a thin film of
emulsifying agent around droplets of the internal phase.

13. COLLOIDAL DISPERSIONS:
Micro Emulsions
 Microemulsions are type of colloidal dispersion consisting of oil and water
phases that have been rendered homogenous, transparent, and physically
stable by the addition of large amounts of surfactants. Unlike emulsions,
microemulsions are thermodynamically stable. The size of microemulsion
droplets is much smaller than that of coarse emulsions and ranges from 6 to
100 nm with a narrow size distribution.
• CO-SURFACTANT: In order to
sufficiently reduce the interfacial tension
between the water and oil phases and form a
microemulsion, it is generally necessary to
include an additional surfactant.

14. PHASE SEPARATION:
CREAMING
Due to density differences between the internal and external phases,
aggregated droplets have a tendency to rise to the top called creaming.
SETTLING
It can maybe fall to the bottom described as settling of the emulsion.The
creaming and settling processes of emulsions can be minimized by
considering the Stoke’s equation.With regard to emulsions, the Stoke’s
equation relates the rate of separation of the dispersed phase to droplet size,
density difference between the phases, and the viscosity of the external phase.
CRACKING OR BREAKING
Cracking or breaking refers to the separation of an emulsion back into its
original two immiscible liquid phases. This can occur due to compromising of
the interfacial film surrounding internal phase droplets, which may be induced
by the addition of an excipient that is incompatible with the emulsifying
agent, bacterial growth, or temperature change. Unlike creaming, cracking is
an irreversible process.

15. CREAMS

16. PHARMACEUTICAL CREAMS
GENERAL INTRODUCTION
What are Pharmaceutical Creams?
Pharmaceutical creams are semisolid
preparations containing one or more
medicinal agents dissolved or dispersed in
either a water-in-oil (W/O) emulsion or an
oil-in-water (O/W) emulsion or in another
type of water-washable base.

17. TYPES OF PHARMACEUTICAL CREAMS:
PHARMACEUTICAL
CREAMS
Water in Oil (W/O)
For example: Cold Creams
Oil in Water (O/W)
For example: Vanishing Creams
Water washable bases
For example: Polyethylene glycol
ointment
On the basis of phase pharmaceutical creams can be divided into three types
which are here following:

18. VANISHING CREAMS:
APPLICATIONS OF PHARMACEUTICAL CREAMS:
-ROUTE OF ADMINISTRATION: Topical
Creams find primary application in topical skin products and in products
used on mucous membranes, such as rectally and vaginally. Many
patients and physicians prefer creams to ointments because they are
easier to spread and remove.
Creams find primary application in topical skin products and in
products used on mucous membranes, such as rectally and vaginally.
Many patients and physicians prefer creams to ointments because they
are easier to spread and remove.

19. PREPARATION
Preparation usually involves separating the formula components into two
portions:
 Lipid
 Aqueous
The lipid portion contains all water-insoluble components and the aqueous
portion the water-soluble components. Both phases are heated to a
temperature above the melting point of the highest melting component. The
phases then are mixed, and the mixture is stirred until reaching ambient
temperature or the mixture has congealed.. Traditionally, the aqueous phase
is added to the lipid phase, but comparable results have been obtained with
the reverse procedure. High-shear homogenization may be employed to
reduce particle or droplet size and improve the physical stability of the
resultant dosage form.
 Preservative: Preservatives are classified into two main classes:
Antimicrobial preservative and antioxidant.

20. •It should liquefy at body temperature.
•It should penetrate the epidermis (via natural opening).
•Its viscosity should be low enough to permit easy spreading.
•It should be non-toxic.
•It should be non-irritant.
•It should be non- inflammatory.
IDEAL CHARACTERISTICS: