m pharmacy notes

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2. By
Ayesha Mulani
Under the guidance of
Mrs. A. K. Salunkhe
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3. basic terminolgy
Surface active agents
Structure of surfactant and properties
Classification of surfactant
HLB scale
Micelles formation
Importance of surfactants
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4. Hydrophilic :A liquid/surface that has a high
affinity to water.
Hydrophobic :A liquid/surface that has very
low affinity to water.
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5.  A molecule that contains a polar portion and a non
polar portion is called surface active agent/
surfactant.
 A surfactant can interact with both polar and
non polar molecules.
 A surfactant increases the solubility of the
otherwise insoluble substances.
 In water, surfactant molecules tend to cluster into a
spherical geometry non polar ends on the inside of
the sphere polar ends on the outside .These clusters
are called micelles
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6. Surfactants have amphipathic structure
tail or hydrophobic group little affinity
for bulk solvent.
Usually hydrocarbon (alkyl/aryl) chain
in aqueous solvents.
Can be linear or branched.
Head or hydrophilic group strong affinity
for bulk solvent.
Can be neutral or charged.
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8.  Surfactants reduce the surface tension of
water by adsorbing at the liquid-gas
interface.
 Many surfactants can also assemble in the
bulk solution into aggregates. Examples of
such aggregates are vesicles and micelles.
 Thermodynamics of the surfactant systems are of
great importance, theoretically and practically.
 Surfactants play an important role as
cleaning, wetting, dispersing, emulsifying, foaming
 And anti-foaming agents in many
practical applications and products
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9. 1.Anionic
2. Cationic
3. Non- Ionic
4. Amphoteric orZwitterionic
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10. Based on permanent anions or pH-dependent anions.
These are categorised as:
 1. Sulfates: Alkyl sulfates, Alkyl ether sulfates
 2. Sulfonates: Sulfonate fluorosurfactants,
Alkyl benzene sulfonates
 3. Phosphates: Alkyl aryl ether phosphate, Alkyl
ether phosphate
 4. Carboxylates: Alkyl carboxylates,
Carboxylate fluorosurfactants
 (~ 60% of industrial surfactants)
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11. Based on pH-dependent primary, secondary or
tertiary amines i.e. primary amines become
positively charged at pH < 10, secondary amines
become charged at pH < 4.
Examples:
 Cetylpyridinium chloride (CPC)
 Polyethoxylated tallow amine (POEA)
 Benzalkonium chloride (BAC)
 Benzethonium chloride (BZT)
 5-Bromo-5-nitro-1,3-dioxane
 Dimethyldioctadecylammonium chloride
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12. Amphoteric surfactants are characterized by the
fact that these surfactants can carry a positive
charge on a cationic site and a negative charge on
an anionic site.
The use of amphoteric terminology is still
restrictive: The charge of the molecule must
change with pH, showing a zwitterionic form at an
intermediate pH
Examples:
 Amino acids
 Imino acids
 Betaines
 lecithin 12SCOP, SATARA

13. They doesnt include any charged head. Theseare
categorised as:
1.Fatty Alcohols
2. Polyoxyethylene glycol
3.Polyoxypropylene gylcol
4. Glucoside
5. Polyoxyethylene glycol octylphenol ethers
6. Sorbitan alkyl esters
7. Polyoxyethylene glycol sorbitan alkylesters
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14. The hydrophilic-lipophilic balance (HLB)
of a surfactant reflects its partitioning
behavior between a polarand non-polar
medium.
HLB number, ranging from 0-40, can
be assigned to a surfactant, based on
emulsification data.
Semi-empirical only.
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16. For non ionic surfactants
HLB = E/5
HLB = 20(1-S/A)
Where ;
E= percentage by weight of ethylene
oxide S= saponification number of ester
A= Acid number of the fatty acid
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17.  Micelles are lipid molecules that arrange themselves
in a spherical form in aqueous solutions. The
formation of a micelle is a response to the
amphipathic nature of fatty acids, meaning that they
contain both hydrophilic regions (polar head
groups) as well as hydrophobic regions.
 Micelles contain polar head groups that usually form
the outside as the surface of micelles. They face to
the water because they are polar. The hydrophobic
tails are inside and away from the water since they
are nonpolar.
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18.  Micelles contain polar head groups that usually form
the outside as the surface of micelles. They face to
the water because they are polar. The hydrophobic
tails are inside and away from the water since they
are nonpolar.
 Micelles form spontaneously in water, as stated
above this spontaneous arrangement is due to the
amphipatic nature of the molecule.
 when the lipids form micelles the hydrophobic tails
interact with each other, and this interaction
releases water form the hydrophobic tail and this
increases the disorder of the system, and this is
increase in entropy is favorable.
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21. Micelles only form when the concentration
of surfactant is greater than the critical
micelle concentration (CMC).
The CMC is the concentration above
surfactant when micelles will form
spontaneously.
Micelle formation also depend on the Krafft
temperature. This temperature is when
surfactants will form micelles.
As the temperature increases, the surfactant
will turn into a soluble form and be able to
form micelles from a crystalline state.
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22.  Solublizing agents
 Wetting agents
 Emulsifying agents in Emulsions
 Suspending agents in
suspensions
 Detergents
 Antifoaming agents
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