This document describes 9 methods for producing niosomes, which are non-ionic surfactant-based vesicles. The methods include ether injection, hand shaking, bubble method, reverse phase evaporation, sonication, multiple membrane extrusion, transmembrane pH gradient loading, microfluidization, and formation from proniosomes. Each method utilizes different processes like solvent evaporation, agitation, extrusion, or pH adjustments to encapsulate drugs in vesicles formed from surfactants and cholesterol.

1. By Tushar Chavan
M Pharmacy 2018-2019
K.Y.D.S.C.T.College of Pharmacy, Sakegaon
NMU, Jalgaon [MH]
Email: tusharchavantsc@gmail.com
Updated April 30, 2019
1 Ether injection method
• This method is based on slow injection of surfactant: cholesterol solution in
ether through 14 gauge needle into a preheated aqueous phase maintained at
600C
• Vaporization of ether resulting into a formation of ether gradient at ether-
water interface which leads to formation of single layered vesicles
• Depending upon the conditions used, the diameter of the vesicle range from
50 to 1000 nm
2. Hand shaking method(Thin film hydration technique)
• Surfactant and cholesterol are dissolved in a volatile organic solvent (diethyl
ether, chloroform or methanol) in a round bottom flask
• The organic solvent is removed under vaccum at room temperature using
rotary evaporator leaving a thin layer of solid mixture deposited on the wall of
the flask
• The dried surfactant film can be rehydrated with aqueous phase at
temperature slightly above the phase transition temperature of the surfactant
used, with gentle agitation
• This process forms large multilamellar niosomes
3. The “Bubble” Method
•It is novel technique for the one step preparation of liposomes andniosomes
without the use of organic solvents
•The bubbling unit consists of round-bottom flask with three neckspositioned
in water bath to control the temperature

2. •Water-cooled reflux and thermometer is positioned in the first andsecond
neck and nitrogen supply through the third neck
• Cholesterol and surfactant are dispersed together in this buffer (pH 7.4)at
70°C, the dispersion mixed for 15 seconds with high shearhomogenizer and
immediately afterwards “bubbled at 70°C usingnitrogen gas.
4. Reverse Phase Evaporation Technique (REV)
•Cholesterol and surfactant (1:1) are dissolved in a mixture of etherand
chloroform
•An aqueous phase containing drug is added to this and the resultingtwo
phases are sonicated at 4-5°C. The clear gel formed is furthersonicated after
the addition of a small amount of phosphate bufferedsaline (PBS)
•The organic phase is removed at 40°C under low pressure. Theresulting
viscous niosome suspension is diluted with PBS and heatedon a water bath at
60°C for 10 min to yield niosomes
5. Sonication
•In this method, an aliquot of drug solution in buffer is added to
thesurfactant/cholesterol mixture in a 10-ml glass vial.
•The mixture is probe sonicated at 60°C for 3 minutes using a sonicator.
•The resultant vesicles are of small unilamellar type niosomes
.6. Multiple membrane extrusion method
• In this method, a mixture of surfactant, cholesterol and diacetyl phosphate is
preparedand then solvent is evaporated using rotary vacuum evaporator to
leave a thin film.
Thefilm is then hydrated with aqueous drug solution and the suspension thus
obtained isextruded through the polycarbonate membrane (mean pore size 0.1
mm) and thenplaced in series up to eight passages to obtain uniform size
niosomes.
•Good method of controlling niosome size.
7. Trans membrane pH gradient (inside acidic) Drug Uptake Process (remote
Loading)
•Surfactant and cholesterol are dissolved in chloroform

3. • The solvent is then evaporated under reduced pressure to get a thin film on
thewall of the round bottom flask
•The film is hydrated with 300 mM citric acid (pH 4.0) by vortex mixing.
•The multilamellar vesicles are frozen and thawed 3 times and later sonicated.
To this niosomal suspension, aqueous solution containing 10 mg/ml of drug is
added and vortexed
• The pH of the sample is then raised to 7.0-7.2 with 1M disodium phosphate•
This mixture is later heated at 60°C for 10 minutes to give niosomes
8. Microfluidization Method
In this method two fluidized streams (one containing drug and the other
surfactant) interact at ultra-high velocity, in precisely defined micro channels
within the interaction chamber in such a way that the energy supplied to the
system remains in the area of niosomes formations.
This is called submerged jet principle. It results in better uniformity, smaller
size and reproducibility in the formulation of niosomes
9. Formation of Niosomes from Proniosomes
•Another method of producing niosomes is to coat a water-solublecarrier such
as sorbitol with surfactant
• The result of the coating process is a dry formulation. In which eachwater-
soluble particle is covered with a thin film of dry surfactant. Thispreparation is
termed “Proniosomes”
•The niosomes are formed by the addition of aqueous phase at T > T mand
brief agitation T = Temperature. Tm = mean phase transition temperature