TRANSDERMAL DELIVERY OF THERAPEUTIC PEPTIDES AND PROTEINS THROUGH VIADERM™
MICROCHANNELS
G Levin and H Gadasi
ąTransPharma Medical Ltd., 2 Yodfat St., Northern Industrial zone, Lod, ISRAEL
The skin has become an alternative route of drug administration for local and
systemic treatments to avoid adverse effects as well as first-pass metabolism.
However, the stratum corneum (SC) is naturally the major limitation for these
treatments. TransPharma Medical has developed an innovative technology to
overcome this obstacle and to enhance the delivery of drug molecules through the
skin.1 The technology is based on a very precise cell ablation using
radio-frequency (RF) electrical energy, which creates MicroChannelsTM across the
SC and into the upper epidermis. The dimensions of the MicroChannelsTM are
controllable and reproducible, due to a built-in feedback mechanism and the
unique proprietary structure of the microelectrode array of the device.
Following a short pretreatment (several seconds), a patch containing a
formulated therapeutic protein is placed on the skin and drug penetration
starts.
The safety and efficacy of the ViaDerm delivery system were demonstrated in a
series of clinical studies. These studies of peptides and proteins transdermal
delivery, demonstrated the delivery of therapeutic levels of the active
materials with relative bioavailability (BA) of up to 60%. The delivered dose
and relative BA were affected and determined by patch dose, microchannel density
as well as the specific qualities of the API. Unexpectedly, drug profiles in the
blood following transdermal delivery resembled those of the SC injection. In
addition to the high delivery and BA, the level of specific biomarkers was
determined in the transdermal delivered groups, compared to the group received
SC injection. This comparison showed that the proteins maintained their
bioactivity during patch manufacturing processes and diffusion through the skin
tissue.
Regarding skin safety, only slight irritation was evident in all the studies
using a microchannels density of 150 to 450 MC/cm2.
In summary, the ViaDerm system is an efficient and safe transdermal delivery
route most suitable as an alternative for undesirable chronic injections of
therapeutic peptides and proteins.
1. A Sintov et at. (2003) Radiofrequency-driven microchanneling as a new way
for electrically assisted transdermal delivery of hydrophilic drugs,J. Cont.
Release 89:311-320.
2. G Levin et al. (2005) Transdermal delivery of human growth hormone through
RF- microchannels. Pharm. Res. 22:550-555.
| 
