Iontophoretic electrodes polarity

The objective of these IPPSF studies was to assess the effect of electroporation on the iontophoretic delivery of LHRH. The experimental design and Porex electrodes have been fully described elsewhere (Heit et al, 1993 1994 Monteiro-Riviere, 1990). Briefly, a 1.0-mg/ml solution of LHRH in lOmM 2-(A-morpholino)ethanesulfonic acid buffer with 154mM NaCl was placed in A.5-cm Ag/AgCl electrodes. Direct current (positive polarity, anode in the donor) was applied at a current density of0.4mA/cm2 for 30min. The venous effluent of the IPPSF was collected and assayed for LHRH using a radioimmunoassay. An electroporative pulse of 500 V and 5-msec exponential time constant was applied immediately prior to iontophoresis. In some experiments, the electroporation/iontophoresis protocol was repeated for various intervals to assess the effect of repeated applications. 

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