NIOSOME overview PDF | PPT

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NIOSOME

➢ Niosomes or non-ionic surfactant vesicles are microscopic lamellar
structures formed on admixture of non-ionic surfactant of the alkyl or
dialkyl polyglycerol ether class and cholesterol with subsequent hydration
in aqueous media.

➢ They are vesicular systems similar to liposomes that can be used as
carriers of amphiphilic and lipophilic drugs.

➢ Niosomes are promising vehicle for drug delivery and being non-ionic, it
is less toxic and improves the therapeutic index of drug by restricting its
action to target cells.

➢ Niosomes are unilamellar or multilamellar vesicles formed from synthetic
non-ionic surfactants.

➢ Niosomal drug delivery is potentially applicable to many pharmacological
agents for their action against various diseases.

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Methods of Preparations

✓ The method of preparation of niosome is based on liposome technology.
✓ The basic process of preparation is the same i.e. hydration by aqueous phase

of the lipid phase which may be either a pure surfactant or a mixture of
surfactant with cholesterol.

✓ The preparation methods should be chosen according to the use of the
niosomes, since the preparation methods influence the number of bilayers,

✓ size, size distribution, and entrapement efficiency of the aqeous phase and
the membrane permeability of the vesciles.

These methods are:
1. Ether injection method
2. Hand shaking method (Thin film hydration technique)
3. Sonication
4. Micro fluidization
5. Multiple membrane extrusion method
6. Reverse Phase Evaporation Technique (REV)
7. Transmembrane pH gradient (inside acidic) Drug Uptake Process
8. The “Bubble” Method

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ETHER INJECTION METHOD

✓ The particle size of the Niosomes formed depend on the conditions used,
and can range anywhere between 50-1000 μm.

A solution of the surfactant is
made by dissolving it in diethyl

ether.

This solution is then
introduced using an injection
(14 gauge needle) into warm

water or aqueous media
containing the drug
maintained at 60 C.

Vaporization of the ether Fig: Steps of Ether injection

leads to the formation of method

single layered vesicles.

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HAND SHAKING METHOD

✓ Also known as Thin film hydration technique

• Mixture of
Surfactant Using rotary

evaporator • The dried
and surfactant film
Cholesterol can be rehydrated

• organic solvent is with aqueous
Dissolved in an removed by low phase at 0-60°C

organic solvent(e.g. pressure at room with gentle

diethyl ether, temperature, agitation.

chloroform, etc.) leaving a thin layer
of solid mixture This

in a round bottomed deposited on the process forms
flask. wall of the flask. typical

multilamellar
niosomes.

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HAND SHAKING METHOD

Fig: Steps of Hand shaking method

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SONICATION

✓ A typical method of production of the vesicles is by sonication of solution

probe
Aliquot of drug Added to the The mixture is

surfactant/ sonicated at 60ºC for 3
Solution in cholesterol mixture minutes using a sonicator

buffer in a 10 ml glass vial with a titanium probe to
yield Niosomes.

Fig: Sonication Method

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MICRO FLUIDIZATION

✓ Micro fluidization is a recent technique used to prepare unilamellar vesicles
of defined size distribution.

✓ This method is based on submerged jet principle.

Two fluidized streams interact at ultra high
velocities, in precisely defined micro channels
within the interaction chamber.

The impingement of thin liquid sheet along a
common front is arranged such that the energy
supplied to the system remains within the area of
Niosomes formation.

The result is a greater uniformity, smaller size
and better reproducibility of niosomes formed.

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MICRO FLUIDIZATION

Fig: Steps of Micro fluidization technique

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Evaluation of Niosomes

Vesicle
diameter

Stability Entrapment
Studies efficiency

Evaluation
of

Niosomes
Drug Bilayer

content rigidity and
homogeneity

In-vitro Niosomal
Drug drug

release loading

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Vesicle diameter

✓ Niosomes, similar to liposomes, assume spherical shape and so their
diameter can be determined using

1. light microscopy,
2. photon correlation microscopy and
3. freeze fracture electron microscopy

✓ Vesicle size measured by using optical microscope with a calibrated
eyepiece micrometer. The vesicle size of 100 niosomes is measured
individually for all batches and its mean value is calculated.

✓ Freeze thawing(keeping vesicles suspension at –20°C for 24 hrs and then
heating to ambient temperature) of niosomes increases the vesicle
diameter, which might be attributed to fusion of vesicles during the cycle.

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Entrapment efficiency

✓ After preparing niosomal dispersion, unentrapped drug is separated by
dialysis, centrifugation, or gel filtration.

✓ 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.

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Bilayer rigidity and Homogeneity

✓ The biodistribution and biodegradation of Niosomes are influenced by
rigidity of the bilayer.

✓ Homogeneity can occur both within Niosomes structures themselves and
between Niosomes in dispersion and could be identified via. NMR,
Differential Scanning Calorimetry (DSC) and Fourier transform-infra red
spectroscopy (FT-IR) techniques.

✓ Membrane rigidity can be measured by means of mobility of fluorescence
probe as a function of temperature.

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Niosomal drug loading

✓ To determine drug loading and encapsulation efficiency, the niosomal
aqueous suspension was ultra-centrifuged, supernatant was removed and
sediment was washed twice with distilled water in order to remove the
adsorbed drug.

✓ The Niosomal recovery was calculated as:

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In Vitro release studies

• A method of in-vitro release rate study includes the use of dialysis
tubing.

• A dialysis sac is washed and soaked in distilled water.

• The vesicle suspension is pipetted into a bag made up of the tubing
and sealed.

• The bag containing the vesicles is placed in 200 ml of buffer
solution in a 250 ml beaker with constant shaking at 25°C or 37°C.

• At various time intervals, the buffer is analyzed for the drug content
by an appropriate assay method.

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Drug Content

✓ Niosomal suspension equivalent to 10mg taken in a volumetric flask of
100 ml and volume was made up by phosphate buffer pH7.4.

✓ After that 1ml of this mixture was diluted to10ml by phosphate buffer pH
7.4 and the percentage dug content was observed at 275nm using UV
spectrophotometer.

Stability Studies

✓ Optimized formulation preserved at refrigerated temperature (4-8±1°C)
and room temperature (25±2°C) for 30days.

✓ After 30days, shape, % drug remaining and % entrapment efficiency of
vesicles were measured. The results were compared with the initial
shape, %drug remaining and % entrapment efficiency of both samples.

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Reference

1. Pranshu Tangri et al (2011) Niosomes: Formulation and Evaluation.International
Journal of Biopharmaceutics; 2(1): 47-53.

2. Mishra N, Srivastava V, Kaushik A, Chauhan V, Srivastava G. Formulation and in-
vitro evaluation of Niosomes of aceclofenac. Journal of Scientific and Innovative
Research. 2014;3(3):337-341.

3. Bragagni M, Mennini N, Ghelardini C, Mura P. Development and characterization
of niosomal formulations of doxorubicin aimed at brain targeting. Journal of
Pharmacy & Pharmaceutical Sciences. 2012 Feb 10;15(1):184-196.

4. Makeshwar KB, Wasankar SR. Niosome: a novel drug delivery system. Asian J.
Pharm. Res. 2013 Jan;3(1):16-20.

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