1: J Control Release.  2003 Mar 7;88(2):253-62.  

Transdermal delivery of timolol by electroporation through human skin.

Denet AR, Preat V.

Unite de Pharmacie Galenique, Universite Catholique de Louvain, Av. E. Mounier,
73 UCL 73.20, 1200 Brussels, Belgium.

The purpose was to achieve therapeutic fluxes of timolol by transdermal delivery
using skin electroporation. The transdermal transport of timolol through human
stratum corneum was studied in three compartment diffusion cells. The
electrodes, buffer composition and pulse conditions were optimized. Timolol
maleate concentration in the donor compartment was 40 mg/ml. Square wave pulses
were applied. Electroporation enhanced the transdermal transport of timolol by
1-2 orders of magnitude as compared to passive diffusion. Even though the
current application lasted for only 10 s, the transdermal transport remained
high after pulsing for at least 6 h. Higher fluxes were obtained with Pt
electrodes close to the skin and a phosphate buffer. 10 pulses of 400 V-10 ms
were more efficient than 10 low voltage-long duration pulses. Therapeutic fluxes
of timolol (>50 microg/cm(2) per h) through human stratum corneum were achieved
by electroporation.

PMID: 12628332 [PubMed - indexed for MEDLINE]