Abstract

SPECTROPHOTOMETRIC ANALYSIS OF THE BINARY MIXTURE CONTAINING OFLOXACIN AND ORNIDAZOLE

Ruba Shdeed* and Imad Shdeed

ABSTRACT

Two spectrophotometric methods are presented for the determination of the binary mixture containing ofloxacin and ornidazole in a combined dosage form without prior separation. The first method is the zero-crossing derivative method (D) where ofloxacin was the only component to be successfully determined by measuring the D1 and D2 amplitudes at 276.2 nm and 295 nm, respectively, in acidic solutions. The second method is the derivative ratio method (DD) where ofloxacin and ornidazole were determined in acidic solutions by measuring the amplitudes of DD1 at 288 nm and 322 nm for ofloxacin, and 261 nm for ornidazole; Also the DD2 amplitudes at 308.5 nm and 265.5 nm were used to quantitate ofloxacin and ornidazole, respectively. Moreover, the DD1 amplitudes, for the alkaline solutions, were successful in determining ornidazole only at 303 nm, while the amplitudes of DD2 of the same solutions were successful in quantitating ofloxacin and ornidazole at 258-266 nm and 298-308 nm, respectively. Furthermore, the aqueous solutions were useful in determining ofloxacin and ornidazole by measuring the DD2 amplitudes at 283 nm and 295.8 nm, respectively; but the amplitudes of DD3 were only used to analyze ornidazole at 302 nm; while the DD1 amplitudes quantitated ornidazole only at 306.5 nm. The methods were linear over the concentration range 2.0-10.0 μgml-1 ofloxacin and 6.0-30.0 μgml-1 ornidazole. The described methods are rapid, accurate, simple and precise and can be used for quality control of such a mixture.

Keywords: Ofloxacin; Ornidazole; Binary Mixture; Derivative Method; Derivative Ratio Method.