1. Presented by;
AITHA SWETHA
M.PHARMACY 1ST YEAR 2ND SEM

2. • Introduction
• Structure of liposomes
• Advantages& disadvantages
• Components of liposome
• Mechanism of liposome
• Preparation methods of liposomes
• Characterization of liposomes
• Applications of liposomes
• Summary
• Niosomes Introduction
• Advantages& disadvantages
• Preparation methods of niosomes
• Characterisation of niosomes
• summary
• References

3. LIPOSOMES
liposomes are concentric bilayered vesicles in which an aqueous
volume is entirely enclosed by a membraneous lipid bilayer
mainly composed of natural or synthetic phospholipids.
Liposomes were first produced in England in 1961 by
Alec D. Bangham. The size of a liposome ranges from some
20 nm up to several micrometers
1

4. Liposome =Phospholipid+
cholesterol
Hydrophillic head
Hydrophobic tail
The lipid moecules are usually phospholipids-amphipathic
moieties with a hydrophilic head group and two hydrophobic tails.
2

5. Advantages of
liposomes:
Provides selective passive targeting to tumor tissues.
(liposomal doxorubicin) .
Increased efficacy and therapeutic index.
Reduction in toxicity of the encapsulated agent.
Site avoidance effect (avoids non-target tissues).
Improved pharmacokinetic effects .
Flexibility to couple with site-specific ligands to achieve
active targeting.
3

6. Disadvantages of liposomes:
Production cost is high.
Leakage and fusion of encapsulated drug /
molecules.
Sometimes phospholipid undergoes oxidation
and hydrolysis like reaction.
Short half-life.
Low solubility.
4

7. Cross-section of liposomes:
Polar Lipids
(Phospholipid)
Lipid Soluble
ingredients
(Drugs,Nutrients
& vitamins)
H2O Layer Water Soluble
ingredients
(Drugs, Nutrients 5
& vitamins)

8. components of liposomes:
The structural components of liposomes
include:
A. Phospholipids
B. cholesterol
6

9. A. General representation of
phospholipids:
7

10. Phospholipids
Phosphatidylcholine- natural
Amphipathic molecule
Hydrophilic polar head-
Phosphoric acid bound to water
soluble molecule.
Glyceryl bridge
Hydrophobic tail-
2 fatty acid chain containing 10-24 carbon
atoms and 0-6 double bond in each chain.
The amphipathic molecule self organise
in ordered supramolecular structure when
confronted (meet face to face)
with solvent.
8

11. The most common natural phospholipid is the
phospatidylcholine (PC ).
Polar Head Groups
Naturally occurring phospholipids used are :
PC: Phosphatidylcholine.
PE: Phosphatidylethanolamine.
Three carbon glycerol
PS: Phosphatidylserine
Synthetic phospholipids used are:
DOPC: Dioleoyl phosphatidylcholine
DSPC: Disteroyl phosphatidylcholine
DOPE: Dioleoyl phosphatidylethanolamine
DSPE: Distearoyl phosphatidylethanolamine
9

12. Molecular geometry on structure of amphiphillic aggregates:
10

13. Molecules of PC are not soluble in water.
In aqueous media they align themselves closely in planar bilayer sheets
in order to minimize the unfavorable action between the bulk aqueous
phase and the long hydrocarbon fatty chain.
Such unfavorable interactions are completely eliminated when the
sheets fold on themselves to form closed sealed vesicles
11

14. PHASE TRANSITION
TEMPERATURE phospholipid membranes can exist
At various temperatures,
in different phases.
The transition from one phase to another can be detected by
technique like micro calorimetry .
What exactly happens during phase transition?
Tightly ordered At elevated temperature liquid crystal phase
gel state
( lipid membrane) (movement is higher)
This is due to the fatty acid chain adopting a new
conformation other than all trans straight chain configuration,
such as gauche configuration state( phenomenon- chain
tilt )
12

15. B. Cholesterol:
Cholesterol stabilizes the Membrane
Steroid lipid
Interdigitates between phospholipids.
i.e. below Tc , it makes membrane less ordered & above Tc more ordered.
Being an amphipathic molecule, cholesterol inserts into the
membrane with its hydroxyl group of cholesterol oriented
towards the aqueous surface and aliphatic chain aligned parallel to
the acyl chains in the center of the bilayer . 13

16. Role of cholesterol in bilayer
formation:
Cholesterol act as fluidity buffer
After intercalation with phospholipid molecules alter the
freedom of motion of carbon molecules in the acyl
Chain
Restricts the transformations of trans to gauche
Conformations.
Incorporated into phospholipid membrane upto 1:1 or
2:1 of cholesterol to PC.
14

17. Mechanism of liposome formation:
15

18. Classification of liposome :
Classification
of liposome
Structural Method of Composition
parameters preparation and application
16

19. Lamella :
Types of vesicles based on lamella
17

20. A. Structural
parameters:
Based on structural
parameters
MLV OLV UV MVV
Multilamellar oligolamellar Multivesicular
Unilamellar
Large vesicles vesicles vesicles
(>0.5 um) (>0.1-1.0 um) Vesicles (> 1.0 UM)
SUV
MUV 20-100nm
GUV LUV
>1um >100nm 18

21. B. Based on REV, SUV made
method of by reverse
phase
preparation: evaporation
method
VET
SPLV
Vesicles Based on
method of Stable
prepared by
preparation plurilamenar
extrusion
vesicles
tech.
FATMLV
Frozen &
thawed MLV 19

22. Based on
composition
and convential
application:
immuno fusogenic
Based on
composition
& application
Long pH
circulatory sensitive
cationic
20

23. MethodS of Liposome Preparation
Passive
Loading of the entrapped agents
loading before/ during the manufacture
technique procedure.
Active/remo Certain types of compounds with
ionizable groups & those with both
te loading lipid & water solubility can be
technique Introduced into liposomes after the
formation of intact vesicles.
21

24. Methods of liposome preparation
Passive loading techniques Active loading techniques
Mechanical dispersion Solvent dispersion Detergent removal
methods methods technique
LIPID FILM HYDRATION ETHANOL INJECTION DETERGENT REMOVAL
BY HAND SHAKING,FREEZE
DRYING OR NON HAND  ETHER INJECTION FORM MIXED MICELLES
SHAKING
 DOUBLE EMULSION BY DIALYSIS
MICRO EMULSIFICATION
REVERSE PHASE CHROMATIGRALPY
SONICATION
 VAPOURATION VESICLES DIFFUSION
FRENCH PRESSURE CELL
STABLE PLURI LAMELLER  VESICLES LIKE….
MEMBRANE EXTRUSON 22
 VESICLES  RECONSTITUTED &
DRIED RECONSTITUTED
 VESICLES  SANDAI VIRUS ENVELOPE

25. General Method Of Liposome
Preparation:
23

26. 1. Mechanical dispersion method:
Lipid dissolve in organic solvent/co-solvent
Remove organic solvent under vacuum
Film deposition
Solid lipid mixture is hydrated by using aqueous buffer
Lipid spontaneously swell & Hydrate
Liposome
Post Hydration vortexing, sonication, freeze thawing &
high pressure extrusion 24

27. There are four basic methods of physical/mechanical
dispersion :
Hand shaken method.
Non shaking method.
Pro – liposomes .
Freeze drying .
25

28. Lipidsform stacks of film
from organic solution
(FE/HS)
Then film is treated with
aqueous medium
Upon hydration lipids
swell and peel out from
RB flask
vesiculate to form Multi
lamellar vesicles(MLVs)
26

29. Pro-liposomes:
 To increase the surface area of dried lipid film & to
facilitate instantaneous hydration.
lipid Dried
over
Finely divided
lipid particulate support Pro - liposomes
like powdered NACL/
sorbital
Pro- Dispersion of MLV’S
water
liposomes
This Method overcome the stability problem. 27

30. Processing of the lipids hydrated by physical means or the
mechanical treatments of MLVs :
Micro Emulsification liposomes (MEL)
Sonicated unilamellar vesicles (SUVs)
French Pressure Cell Liposomes .
Membrane extrusion Liposomes
Dried reconstituted vesicles(DRVs)
Freeze thaw sonification (FTS)
pH induced vesiculation
Cochleate method. 28

31. Sonicated unilamellar vesicles:
The exposure of MLVs to ultrasonic
irradation for producing small vesicles.
Probe sonicator Bath sonicator
Used for dispersions large volume
require high of dilute lipids
energy in
small volumes
Sonication
MLVs hazy transparent
5-10 min solution
centrifugation 30 min
clear SUV 29
Dispersion.

32. Micro emulsification liposomes:
30
Micro fluidizer

33. French pressure cell liposomes:
Extrusion of preformed large liposomes in french press under very
high pressure .
uni or oligo lamellar liposomes of intermediate size (30-80nm ) .
Advantages
Less leakage and more stable liposomes are formed compared to
sonicated forms
31

34. Vesicles prepared by extrusion technique :
The size of liposomes is
reduced by gently passing them
through polycarbonate
membrane filter of defined
pore size at lower pressure
Used for preparation of LUVs
and MLVs
32

35. Dried reconstituted vesicles& freeze thaw sonication method
33

36. pH induced vesiculation:
The transient change in pH brings about
an increase in surface charge of the lipid
bilayer which induces spontaneous LUVs
vesiculation .
Reduced the pH
to 7.5
Exposed to high pH * Addition of
~ (addition of 1M 0.1M Hcl
Preformed NaoH)
MLV’S
~Period of
(2.5-3.0)
exposure < 2min
MLVs 34

37. Cochleate method:
Cochleates
Removal
of Ca++ by
Cylindrical EDTA
rolls(cochleate
Addition of cylinders)
Ca++ ions
SUVs made
from
phosphatidylse
rine(PS)
35

38. Solvent dispersion methods:
Lipid dissolve in organic solvent
Excess addition of aqueous phase
Lipids allign at interface of aqueous and organic layer
Formation of monolayer and bilayer of phospholipids
Liposome
Note:- Organic solvent miscible with aqueous phase
36

39. Solvent dispersion methods:
ETHANOL INJECTION/ETHER INJECTION:
37

40. De-Emulsification method:
Generally the liposome is made up in 2 steps: Aqueous medium
containing material
1 st the inner leaflet of the bilayer . to be entrapped
Then the outer half.
Add to immiscible
organic solution of
lipid
Mechanical agitation
Microscopic water
droplets
Methods to prepare the droplets:
~Double emulsion vesicles
~Reverse phase evaporation vesicles 38
~Sonication methods

41. Reverse phase evapouration method:
39

42. DETERGENT SOLUBILISATIOIN METHODS
Phospholipid brought into intimate contact with
aqueous phase
By addition optimized concentration of detergent
Formation of micelles (Liposome)
Below CMC, detergent molecules exist in free soln. As the
concentration is increased, micelles are formed.
Note:- Liposome size and
Methods to remove detergents:
shape depend on chemical
Dialysis
nature of
Column chromatography.
detergent, concentration and 40
other lipid involved

43. Active/remote loading technique:
The lipid bilayer membrane is impermeable to ions & hydrophilic
molecules. But, Permeation of hydrophobic molecules can be controlled
by concentration gradients.
Some weak acids or bases can be transported due to various
transmembrane gradients
Electrical gradients.
Ionic(pH) gradients.
Chemical potential gradients.
Weak amphipathic bases accumulate in aq phase of lipid vesicles
in response to difference in pH b/w Inside & outside of
liposomes 41

44. Solute bearing no Liposomes with low
internal pH
charge at neutral pH pH gradient is created by preparing liposomes
with low internal pH.
Addtn of base to extraliposomal medium.
[Basic compds ( lipophilic (non ionic) at high
pH & hydrophilic(ionic) at low pH)]
Neutral solute passes Lipophilic (UNPROTONATED) drug diffuse
easily through bilayer through the bilayer
membrane by
diffusion
At low pH side, the molecules are
predominantly protonated .
Exchange of external medium by gel extrusion
chromatorapghy with neutral solution.
Charge aquired by
solute inside Weak bases like doxorubicine,
liposomes makes adriamycin and vincristine are
them unable to exit encapsulated. 42

45. Locus of drugs in liposomes:
Hydrophilic (DOXORUBICIN)
Low entrapment
Leakage
Hydrolytic degradation
Lipophilic (CYCLOSPORINE)
High entrapment
Low leakage
Chemical stability
Ampiphilic (VINBLASTIN)
High entrapment
Rapid leakage
Biphasic insoluble
(ALLOPURINOL, 6-
MERCAPTOPURINE)
Poor loading & entrapment 43

46. Characterization of liposomes:
PHYSICAL CHARACTERISATION CHEMICA L CHARACTERISATION
→ Vesicles size/shape/morphology → Phospholipids /lipid concentration
→ Surface -charge/electrical potential → Drug concentration
→ Phase behaviour/ lamellarity → PH / Osmomolality
→ Drug release →Antioxidant degradation
→ % capture /free drug → Phospholipids / cholesterols –
peroxidation/oxidation/hydrolysis
BIOLOGICAL CHARACTERISATION
→ Sterility
→ Pyrogenisity
→ Animal toxicity
44
→Plasma Stability:

47. Characterization parameters Analytical method/Instrument
1. Vesicle shape and surface morphology Transmission electron microscopy, Freeze-
fracture electron microscopy
2.Mean vesicle size and size distribution Photon correlation spectroscopy, laser light
(submicron and micron range) scattering, gel permeation and gel exclusion
3. Surface charge Free-flow electrophoresis
4. Electrical surface potential and surface pH Zetapotential measurements
5. Lamellarity Small angle X-ray scattering, 31 P-NMR, Freeze-
fracture electron microscopy
6. Phase behavior Freeze-fracture electron microscopy, Differential scanning
calorimetery
7. Percent of free drug/ percent capture Minicolumn centrifugation, ion-exchange
chromatography, radio labelling
8. Drug release Diffusion cell/ dialysis
45

48. Characterization parameters Analytical method/Instrument
1. Phospholipid concentration Barlett assay, stewart assay, HPLC
2. Cholesterol concentration Cholesterol oxidase assay and HPLC
3. Phopholipid peroxidation UV absorbance
4. Phospholipid hydrolysis, HPLC and TLC
Cholesterol auto-oxidation.
5. Osmolarity Osmomete
46

49. Characterization parameters Analytical method/Instrument
1. Sterility Aerobic or anaerobic cultures
2. Pyrogenicity Limulus Amebocyte Lysate (LAL) test
3. Animal toxicity Monitoring survival rates, histology and
pathology
STABILITY OF LIPOSOMES:
Stability invitro .
~ Lipid oxidation
~ Lipid peroxidation
~ Long term & accelerated stability
Stability after systemic administration.
47

50. 1. Endocytosis 2. Adsorption
3. fusion 4. Lipid transfer
48

51. Encapsulation of drugs in liposomes:
• Encapsulation volume/Trapped volume
Volume of aqueous solution entrapped in liposomes per mole of PL (µL/µmol PL)
• Encapsulation Efficiency
Assessed by mini column centrifugation method & protamine aggregation method.
protamine aggregation method used for neutral and negetively charged liposomes.
Liposome dispersion can be precipitated with protamine solution and subsequent
centrifugation at 2000RPM.
By analysing the material in super natent & in liposome pellet ( after disrupting
liposomal pellet with 0.6 ml of 10% triton x-100 ). The encapsulation efficiency of
entrapped material can be estimated.
• % Encapsulation
Drug entrapped in liposomes
x 100
Total drug added
49

52. In gene delivery.
As drug delivery carriers.
Enzyme replacement therapy.
Chelation therapy for treatment of heavy metal poisoning.
Liposomes in antiviral/anti microbial therapy.
In multi drug resistance.
In tumour therapy.
In immunology.
In cosmetology
50

53. DNA delivery of Genes by Liposomes
Cheaper than viruses
No immune response
Especially good
for in-lung delivery (cystic fibrosis)
100-1000 times more plasmid DNA needed
for the same transfer efficiency as for viral vector 51

54. Lipofection
52

55. Liposomes could serve as tumor specific vehicles
(even without special targeting)
Liposomes better penetrate into tissues
with disrupted endothelial lining 53

56. DRUG ROUTE OF APPLICATION TARGETED DISEASES
ADMINISTRATION
Amphotericin B Oral delivery Ergosterol membrane Mycotic infection
Insulin Oral,ocular,pulmonary Decrease glucose level Diabetic mellitus
And transdermal
Ketoprofen Ocular delivary Cyclooxygenase enzyme inhibitor Pain muscle condition
Pentoxyfyllin Pulmonary delivery phosphodiesterase Asthama
Tobramycin Pulmonary delivery Protein synthesis inhibitor Pseudomonas
infection,aeroginosa
Salbutamol Pulmonary delivery ß2-adrenoceptor antagonist Asthama
Cytarabin Pulmonary delivery DNA-polymerase inhibition Acute leukameias
Benzocaine Transdermal Inhibition of nerve impulse from Ulcer on mucous surface
sensory nerves with pain
Ketaconazole Transdermal Inhibit ergosterol membrane Candida albicans
Levanogesterol Transdermal Rhamnose receptor skin disorder
hydroxyzine Transdermal H1-receptor antagonist Urtecaria,allergic skin
disease
Ibuprofen Oral delivery Chaemoceptor,free ending Rheumatoid arthritis
triamcilonone Ocular delivery,Transdermal Inhibition of prostaglandin Anti-inflammatory
54

57. NAME TRADE NAME COMPANY INDICATION
Liposomal Abelcet Enzon Fungal infections
amphotericin B
Liposomal Ambisome Gilead Sciences Fungal and protozoal infections
amphotericin B
Liposomal cytarabine Depocyt Pacira (formerly Malignant lymphomatous meningitis
SkyePharma)
Liposomal DaunoXome Gilead Sciences HIV-related Kaposi’s sarcoma
daunorubicin
Liposomal doxorubicin Myocet Zeneus Combination therapy with cyclophosphamide in
metastatic breast cancer
Liposomal IRIV vaccine Epaxal Berna Biotech Hepatitis A
Liposomal IRIV vaccine Inflexal V Berna Biotech Influenza
Liposomal morphine DepoDur SkyePharma, Endo Postsurgical analgesia
Liposomal verteporfin Visudyne QLT, Novartis Age-related macular degeneration, pathologic
myopia, ocular
histoplasmosis
Liposome-PEG Doxil/Caelyx Ortho Biotech, HIV-related Kaposi’s sarcoma, metastatic breast
doxorubicin Schering-Plough cancer, metastatic
ovarian cancer
55
Micellular estradiol Estrasorb Novavax Menopausal therapy

58. summary:
o liposomes are concentric bilayered vesicles in which an aqueous
volume is entirely enclosed by a membraneous lipid bilayer
o Liposomes are one of the unique drug delivery system, in controlling
and targeting drug delivery.
o Components of liposomes include phospholipid and cholesterol.
o Method of preparation of liposomes include active loading technique
and passive loading technique.
o Passive loading techniques include solvent mechanical dispersion,
solvent dispersion & detergent solubilisation
o Characterization of liposomes include physical,chemical and
56
biological.

59. NIOSOMES

60. Niosomes are non-ionic surfactant based unilamellar or multilamellar
bilayer vesicles up on hydration of non ionic surfactants with or
without incorporation cholesterol .
The niosomes are very small, and microscopic in size. Their size lies
in the nanometric scale.
Niosomes are a novel drug delivery system, in which the medication is
encapsulated in a vesicle. Both hydrophilic
& lipophilic drugs ,entrap either in the
aqueous layer or in vesicular membrane
made of lipid materials.
57

61. Hydrophilic drugs Polar heads facing
Structure of niosomes: located in hydrophilic region
aqueous regions
Head part encapsulated
(hydrophillic)
Tail part
(hydrophobic)
Drug molecules
Hydrophobic drugs
localized in the
Phospholipids hydrophobic
lamellae
These vesicular systems are similar to liposomes that can be
used as carriers of amphiphilic and lipophilic drugs.
It is less toxic and improves the therapeutic index of drug by
restricting its action to target cells. 58

62. Advantages of niosomes:
They are osmotically active and stable.
They increase the stability of the entrapped drug.
The vesicle suspension being water based offers greater patient
compliance over oil based systems
Since the structure of the niosome offers place to accommodate
hydrophilic, lipophilic as well as ampiphilic drug moieties, they can be
used for a variety of drugs.
The vesicles can act as a depot to release the drug slowly and of
controlled release.
Biodegradable, non-immunogenic and biocompatible. 59

63. Aggregation
Fusion
Leaking of entrapped drug
Hydrolysis of encapsulated drugs which limiting the shelf
life of the dispersion.
60

64. Classification of niosomes
Small Large
Unilamellar Unilamellar Multilamellar
Vesicle Vesicle Vesicle
(SUV) (LUV) (MLV)
Typical Size Ranges: SLV: 20-50 nm – MLV:100-1000 nm
61

65. Components of niosomes:
Cholesterol and Non ionic surfactants are the two major components
used for the preparation of niosomes.
Cholesterol provides rigidity and proper shape. The surfactants play a
major role in the formation of niosomes.
non-ionic surfactants like spans(span 20,40,60,85,80), tweens (tween
20,40,60,80) are generally used for the preparation of
Niosomes.
Few other surfactants that are reported to form niosomes are as follows :
Ether linked surfactant
Di-alkyl chain surfactant
Ester linked
Sorbitan Esters
Poly-sorbates
62

66. alkyl group chain
length : C12-C18
Shud be above Span surfactants
the gel to liquid with HLB values
phase transition 4 and 8
temperature of Hydration Non-ionic
the system Temperature surfactant
nature
Factors
affecting
Surfactants niosomes
and lipid Membrane
formation additives
levels
surfactant/lipid
ratio: 10-30 mM Nature of Cholesterol: Prevent
encapsulated vesicle aggregation.
drug Dicetyl phosphate: -ve
charge
63

67. Concept of Critical Packing Parameter
Prediction of vesicle forming ability is not a simply a matter of HLB
CPP = v/lca0
where
v - hydrophobic group volume,
lc - critical hydrophobic group length and
a0 - area of the hydrophilic head group
CPP between 0.5 and 1 likely to form vesicles.
< 0.5 (indicating a large contribution from the hydrophilic head group
area) is said to give spherical micelles.
>1 (indicating a large contribution from the hydrophobic group volume)
should produce inverted micelles.
64

68. Comparisition between liposomes &
niosomes:
Sl. Liposomes Niosomes
No.
1. Vesicles made up of concentric Vesicles made up of surfactants
bilayer of phospholipids with or without incorporation of
cholesterol.
2. Size ranges from 10-3000nm Size ranges from 10-100nm
3. Comparatively expensive Inexpensive
4. Special storage condition are No such special requirement
required
5. Phospholipids used are unstable Non-ionic surfactants are stable
6. Comparatively more toxic Less toxic
65

69. Methods of Niosome preparation:
Hand Shaking method
 Reverse phase evaporation technique
 Ether Injection method
Multiple membrane extrusion method
Bubble method
 Sonication
 From Proniosomes
66

70. Hand shaking method:
Rotary evaporator
67

71. Reverse phase evaporation technique :
Surfactant is dissolved in chloroform ond 0.25 volume of PBS buffer is
emulsified to get a W/O emulsion.
sonicated
chloroform is evaporated under reduced pressure.
The lipid or surfactant forms a gel first and hydrates to form vesicles.
Free drug (unentrapped) is generally removed by dialysis.
sonication:
Surfactant +cholesterol Mixture is sonicated for 3
mixture is dispersed in 2 ml min at 60 C using titanium
aqueous phase in vial probe sonicator
Unilamellar niosomes 68

72. 14 guage needle
Ether injection Method:
69

73. Multiple membrane extrusion Method:
•Mixture of surfactant, cholesterol and
dicetyl phosphate in chloroform is made
into thin film by evaporation
•The film is hydrated with aqueous drug
solution and the resultant suspension
extruded through polycarbonate membranes
70

74. Bubble method:
RBF as bubbling unit with three necks in water
It is novel technique for the bath.
one step preparation of
liposomes and niosomes Reflux , thermometer and nitrogen supply by
three necks
without the use of organic
solvents. Cholesterol+ Surfactant dispersed in buffer
pH 7.4 at 70°C
Above dispersion is homogenized for 15 sec and
then bubbled with nitrogen gas at 70°C to get
niosomes
71

75. proniosomes:
• Bubble Method
• Formation of niosomes from proniosomes:
It is prepared by coating water-soluble carrier such as sorbitol with
surfactant. The result of the coating process is a dry formulation. In
which each water-soluble particle is covered with a thin film of dry
surfactant. This preparation is termed “Proniosomes”.
72

76. Separation of unentrapped drug:
Gel filtration Separation of
unentrapped Centrifugation
drug The niosomal suspension
The unentrapped drug is
is centrifuged and the
removed by gel filtration of
supernatant is separated.
niosomal dispersion through a
The pellet is washed and
Sephadex-G-50 column and
then resuspended to obtain
elution with phosphate
a niosomal suspension free
buffered saline Dialysis from unentrapped drug.
Dialyzed in a dialysis tubing
against phosphate buffer or
normal saline
Gel Filtration Centrifuser 73

77. a) Size, Shape and Morphology
Freeze Fracture Electron Microscopy:- Visualize the vesicular structure of
surfactant based vesicles.
Photon Correlation spectroscopy :- Determine mean diameter of the
vesicles.
Electron Microscopy :- Morphological studies of vesicles.
b) Entrapment efficiency
After preparing niosomal dispersion, unentrapped drug is separated by
dialysis and the drug remained entrapped in niosomes is determined by
complete vesicle disruption using 50% n-propanol or 0.1% Triton X-100
and analysing the resultant solution by appropriate assay method for the
drug.
c) Vesicle Suface Charge
Determined by measurement of electrophoretic mobility and expressed in
expressed in terms of zeta potential
d) In vitro studies 74

78. Applications
Oral
immunological Diagnostic
Leishmaniasis Oncology drug Transdermal
adjuvants imaging
delivery
75

79. Lancôme has come out with a variety of anti-ageing
products which are based on noisome formulations.
L‟Oreal is also conducting research on anti-ageing
cosmetic products.
76

80. Summary :
 Niosomes provide incorporating the drug into for a
better targeting of the drug at appropriate tissue
destination .
 They presents a structure similar to liposome and hence
they can represent alternative vesicular systems with
respect to liposomes
 Niosomes are thoughts to be better candidates drug
delivery as compared to liposomes due to various factors
like cost, stability etc. Various type of drug deliveries can
be possible using niosomes like targeting, ophthalmic,
topical, parenteral etc.
77

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Delivery,liposomes,173-279.
2. Mohammad Riaz, Liposomes :Preparation Methods,
Pakistan Journal Of Pharmaceutical Sciences, January
1996,Vol.19(1),65-77.
3. Sharma Vijay K1*, Liposomes: Present Prospective and
Future Challenges,International Journal Of Current
Pharmaceutical Review And Research, oct 2010,vol1,
issue 2,6-16
4. Himanshu Anwekar*, Liposome- as drug carriers,
International Journal Of Pharmacy & Life Sciences,
Vol.2, Issue 7: July: 2011, 945-951
78

82. 5. Madhav Nvs* And Saini A, Niosomes: A Novel
Drug Delivery System, International Journal Of
Research In Pharmacy And Chemistry, 2011,
1(3),498-511.
6. Lohumi Ashutosh, Rawat Suman, A Novel Drug
Delivery System: Niosomes Review, Journal Of Drug
Delivery & Therapeutics; 2012, 2(5), 129-135.
7. Pawar Sd *, Pawar Rg, Niosome: An Unique Drug
Delivery System, International journal Of Pharmacy,
Biology and Allied Sciences, April, 2012, 1(3): 406-416.
8. Rajesh Z. Mujoriya, Niosomal Drug Delivery System –
A Review, International Journal Of Applied
Pharmaceutics, Vol 3, Issue 3, 2011,7-10.
79

83. Success in life mostly depends on the power of
„CONCENTRATION‟
--- Swami Vivekananda