The rate of penetration of most drugs through the skin is controlled by the structure of
the stratum corneum. The ability of the skin to impede the permeation of molecules
means that, to date, only a small number of pharmaceutically active compounds have
been suitable for conventional transdermal delivery. Many drugs will be absorbed but
in such small quantities per area of skin per hour that a very large application area
would be needed to achieve levels of concentration in the blood high enough to have
therapeutic effects.
The ethosome delivery system technology
NTT Inc. was established to developed a patented, passive, non-invasive, transdermal drug delivery
technology known as the Ethosome Delivery System.
Ethosomes are soft, malleable vesicles that are mainly composed of phospholipids,
relatively high concentrations of ethanol and water. All components utilised in Ethosomal
systems are approved for pharmaceutical and cosmetic use in the category ‘Generally
Recognised as Safe’.
Comparative studies of existing transdermal drug delivery systems and the Ethosome
technology have proven a significant superiority of the Ethosome. Ethosomal systems
are sophisticated conceptually, but characterized by simplicity in their preparation, safety
and efficiency– a rare combination that could expand their applications. The highly
efficient delivery makes this system a promising candidate for the administration of
bioactive compounds in gel, cream and spray dosage forms. This novel technology is
protected under international patents.
Ethosomal systems have been shown to have a high entrapment capacity for both
lipophilic and hydrophilic molecules and to be more efficient at delivering drugs through the
skin (in terms of quantity and depth) compared with some liposomal formulations and
other existing transdermal delivery systems. Ethosomal systems may therefore be
employed to enhance the delivery of a variety of drugs through and across the skin.
Transdermal systems may represent an alternative route of delivery for drugs that cannot
currently be administered by other drug delivery methods.
Ntt's Ethosome Technology originated in pharmaceutical research carried out by Prof. Elka Touitou at the Hebrew University in Jerusalem.
