Abstract

PRIETO, Avismelsi et al. Optimization of spectrophotometric methods using response surfaces methodology. Rev. Téc. Ing. Univ. Zulia [online]. 2007, vol.30, n.Especial, pp.98-107. ISSN 0254-0770.

Response surface methods are very useful in order to interpret the relationships between response and factor effects. The relationships can be represented by polynomials of second order or explored graphically to determine the optimum levels. This paper describes the development of two spectrophotometric methods for the determination of ciprofloxacin and norfloxacin in pharmaceutical formulations. The optimization of variables were studied both in the traditional mode and using response surface methodology. The methods are based on the reaction between ciprofloxacin and norfloxacin with the bromocresol green in acid medium, to give ion-pairs extractable with chloroform. The ion pairs formed exhibited absorption maximum at 420 nm. Beer’s law is obeyed in the concentration ranges 2,0-40,0 µg/mL and 2,0-80,0 µg/mL for ciprofloxacin and norfloxacin respectively. The analysis yielded good reproducibility (RSD between  0,40-5,88%). The proposed methods were applied on the ciprofloxacin and norfloxacin determination in tablets and intravenous solution, shows recoveries in the range of 98,4-104,1%. The proposed methods are simple, sensitive and economic.

Keywords : Response surface methodology; spectrophotometry; ciprofloxacin; norfloxacin.