ELECTROANALYSIS OF B-TETRAHYDROOXAZOLO[3,2][1,4]-BENZODIAZEPIN-6-(5H)(HALOXAZOLAM)

Sulfuric acid (2.7 m) with 10% (vol.) ethylene glycol dimethylether pr ovides sufficient stability of the electroactive form of haloxalozam ( 1) and may be used as a supporting electrolyte for its DCP or DPP dete rmination in pharmaceutical preparations. The polarographic behaviour of 1 was investigated: the polarographic curves are markedly influence d by the hydrolysis of the original inactive form 1 to the iminium spe cies A and further to the substituted benzophenone B in which both het erocyclic rings have been opened. The mechanism and the kinetics of th ese hydrolytic reactions have been studied and an interpretation has b een suggested. The recommended determination is based on the 2-electro n reduction of A. The lower sensitivity limit is 2.5 . 10(-5) mol . l( -1) in the DC mode and 2.5 . 10(-6) mol . l(-1) in DPP. In the analysi s of single tablets the relative standard deviation S-rel is 1.8 for 5 mg and 3.8 for 10 mg tablets (both DCP). Therefore, this polarographi c method is suitable for the content uniformity test.