Ethosomes

Godin B, Touitou E. Ethosomes new prospects in transdermal delivery. Crit Rev Ther Drug Carrier Syst 2003 20 63-102. 

Touitou E, Godin B, Weiss C. Enhanced delivery of drugs into and across the skin by ethosomal carriers. Drug Dev Res 2000 50 406-415. 

Touitou E, Dayan N, Bergelson L, Godin B, Eliaz M. Ethosomes—novel vesicular carriers for enhanced delivery characterization and skin penetration. J Control Release 2000 65 403-418. 

ETHOSOMES—SOFT PHOSPHOLIPID VESICLES FOR ENHANCED DERMAL AND TRANSDERMAL DELIVERY... 

Although frequently referred to as a kind of liposomes, ethosomes are very different from other lipid vesicles by their composition, structure, mechanism of action, and delivery properties. Ethosomal carriers contain soft lipid vesicles (mainly composed of phospholipids, ethanol, and water) in a hydroethanolic milieu. They have appropriate features, designed to allow for enhanced delivery by passive transport to the deep skin strata and through the skin [86-90], Their delivery enhancing properties can be modulated by changes in the composition and structure. Ethosomes, invented by Touitou [86-88], were so named to emphasize the... 

FIGURE 13.5 (a) Visualization of a typical multilamellar ethosome containing 2% PL, 30% ethanol, and water by TEM (b) Entrapment of fluorescent probes by phopholipid vesicles as visualized by CSLM. Liposomes (a-c) or ethosomes (d-f) were prepared with one of three fluorescent probes rhodamine red (a, d), D-289 (b, e), or calceine (c, f). White represents the highest concentration of probe. (Reproduced from Touitou, E. et al., J. Control. Release, 65, 403, 2000. With permission from Elsevier.)... 

FIGURE 13.6 Proposed mechanism for permeation of molecules from ethosomal system through stratum corneum (SC) lipids. (Reproduced from Touitou, E. et al., J. Control. Release, 65, 403, 2000. With permission from Elsevier.)... 

FITC-Bac) delivered in vivo from ethosomes, penetrated the rat skin through the intercor-neocyte pathways, which typically exist along the lipid domain of the stratum corneum [95] (Figure 13.7). In contrast, significantly lower fluorescence staining of the intercellular penetration pathway and no inter- or intracorneocyte fluorescence were observed with FITC-Bac hydroethanolic solution and liposomes, respectively. 

Charged and hydrophilic large molecules (polypeptides, proteins) were challenging compounds tested with ethosomal carriers [93,98-100]. The ability of trihexyphenidyl hydrochloride... 

FIGURE 13.9 Delta blood glucose levels measured following in vivo application to the abdominal area of ethosomal insulin vs. no treatment in (a) diabetic and (b) normal SD-1 rats. 

The stability of ethosomal systems incorporating various drugs was assessed in a number of studies by comparing the average diameter and the structure of the vesicles during a 2-year period at room temperature [86,93,94]. The mean size of empty and cationic trihexyphenidyl... 

Studies conducted with ethosomal systems in vitro, in vivo, and in humans confirm that these soft vesicles enable efficient transport of active agents into the deep strata and across the skin. The above mentioned drugs that have been tested with ethosomal carriers are clearly not exhaustive but intended to illustrate the wide range of molecules that could be tailored with ethosomes for facilitating dermal, transdermal, or follicular delivery. 

Touitou, E., et al. 2000. Ethosomes-novel vesicular carriers for enhanced delivery Characterization and skin penetration properties. J Control Release 65 403. 

Dayan, N., and E. Touitou. 2000. Carriers for skin delivery of trihexyphenidyl HC1 Ethosomes vs. liposomes. Biomaterials 21 1879. 

Godin, B., and E. Touitou. 2005. Erythromycin ethosomal systems Physicochemical characterization and enhanced antibacterial activity. Curr Drug Deliv 2 269. 

Lodzki, M. 2002. Transdermal delivery of cannabidiol by ethosomal carrier. MSc thesis, The Hebrew University of Jerusalem, Jerusalem, Israel. 

Touitou, E., et al. 2002. Transdermal delivery of cannabinoids by ethosomal carriers, 4th World Meeting ADRITELF/APV/APGI Abstracts, Florence. 

Godin, B., et al. 2005. A new approach for treatment of deep skin infections by an ethosomal antibiotic preparation An in vivo study. J Antimicrob Chemother 55 989. 

Godin, B., M. Alcabez, and E. Touitou. 1999. Minoxidil and Erythromycin targeted to pilosebac-eous units by ethosomal delivery systems. Acta Technol Legis Medicament 10 107. 

Paolino, D., et al. 2005. Ethosomes for skin delivery of ammonium glycyrrhizinate In vitro percutaneous permeation through human skin and in vivo anti-inflammatory activity on human... 

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