Gas chromatographic-mass spectrometric determination of two new antimycotic agents, 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole and 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole, in rabbit plasma following topical administration: a preliminary comparison with bifonazole.

ABSTRACT

A method for the analysis of the antimycotic drugs 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole, 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole and bifonazole in rabbit plasma, employing gas chromatography-mass spectrometry with selected-ion monitoring, was developed. The procedure involved single-step purification of the biological matrix via liquid-liquid extraction on Extrelut columns and use of a carrier substance to minimize the negative effects of adsorption sites during the gas chromatographic process. The limits of detection ranged from 0.1 to 1.4 ng/ml, starting from a 200-microliter sample. The method was applied to a preliminary evaluation of percutaneous absorption of both drugs in the rabbit after a single administration, in comparison with bifonazole.