ETHOSOMES: AN OVERVIEW

Ethosomes are soft, malleable vesicles and potential carrier for transportation of drugs. Ethosomes are characterized by simplicity in their preparation, safety and efficacy and can be tailored for enhanced skin permeation of active drugs. Ethosomes have been found to be much more efficient at delivering drug to the skin, than either liposomes or hydro alcoholic solution. Ethosomes have been tested to encapsulate hydrophilic drugs, cationic drugs, proteins and peptides. Ethosomal carrier opens new challenges and opportunities for the development of novel improved therapies.


Introduction:
Ethosomes are novel carrier system used  The water heated to 300 0 C in a separate vessel is added to the mixture, which is then stirred for 5 min in a covered vessel.
The vesicle size of ethosomal formulation can be decreased to desire extend using sonication or extrusion method. Finally, the formulation is stored under refrigeration.

Hot method 9-10
In this method phospholipid is dispersed in water by heating in a water bath at 400 0 C until a colloidal solution is obtained. In a separate vessel ethanol and propylene glycol are mixed and heated to 400 0 C.
Once both mixtures reach 400 0 C, the organic phase is added to the aqueous one.
The drug is dissolved in water or ethanol depending on its hydrophilic/ hydrophobic properties. The vesicle size of ethosomal formulation can be decreased to the desire extent using probe sonication or extrusion method.

Visualization 11
Visualization of ethosomes can be done using transmission electron microscopy (TEM) and by scanning electron microscopy (SEM).

Vesicle size and Zeta potential 12
Particle size and zeta potential can be determined by dynamic light scattering (DLS) using a computerized inspection system and photon correlation spectroscopy (PCS).

Entrapment Efficiency 13
The entrapment efficiency of drug by ethosomes can be measured by the ultra centrifugation technique.

Transition Temperature 14
The transition temperature of the vesicular lipid systems can be determined by using differential scanning calorimetry.

Measurement 15
The surface tension activity of drug in aqueous solution can be measured by the ring method in a Du Nouy ring tensiometer.

Vesicle Stability 16
The stability of vesicles can be determined by assessing the size and structure of the vesicles over time. Mean size is measured by DLS and structure changes are observed by TEM.

Studies 17
Depth of penetration from ethosomes can be visualized by confocal laser scanning microscopy (CLSM). Finally, filters were coated with gold and examined in SEM (Leica, Bensheim, Germany).

Skin Permeation Studies
The hair of test animals (rats) were

Stability Study
Stability of the vesicles was determined by storing the vesicles at 4°C ± 0.5°C. Vesicle size, zeta potential, and entrapment efficiency of the vesicles was measured after 180 days using the method described earlier.

Vesicle-Skin Interaction Study by TEM and SEM
From animals ultra thin sections were cut

Hormones 21
Oral administration of hormones is associated with problems like high first pass metabolism, low oral bioavailability and several dose dependent side effects.
The risk of failure of treatment is known to increase with each pill missed.

Transcellular Delivery 22
Ethosomes as compared to the marketed formulation suggested ethosomes to be an attractive clinical alternative for anti-HIV therapy.

Topical Delivery of DNA 23
Many environmental pathogens attempt to enter the body through the skin. Skin therefore, has evolved into an excellent protective barrier, which is also immunologically active and able to express Better skin permeation ability of ethosomes opens the possibility of using these dosage forms for delivery of immunizing agents.

Delivery of Anti-Arthritis Drug 24
Topical delivery of anti-arthritis drug is a better option for its site-specific delivery and overcomes the problem associated with conventional oral therapy.