ELECTROCHEMICAL STABILITY OF DESMOPRESSIN ACETATE DURING IONTOPHORESIS

The electrochemical stability of desmopressin acetate (DDAVP) as inves tigated, lifter a direct current of 1 mA as passed through tno electro des chosen from platinum, silver and silver chloride, the decompositio n of DDAVP was observed. The degradation products of DDAVP yielded wit h a Pt(anode) and AgCl(cathode) pair were similar to those observed in an anodic donor after in vivo iontophoresis. Although the Ag(anode)/P t(cathode) degradation pattern of DDAVP or as similar to that of an in vivo cathodic donor HPLC chromatogram, it was different from that of the anodic donor. In the anodic system, the stability of DDAVP was ind ependent of the pH,and decreased with increasing concentration of NaCl .