Quantitative determination of ciprofloxacin and norfloxacin in pharmaceutical preparations by high performance liquid chromatography

Abstract

O objetivo desta pesquisa foi desenvolver e validar um método analítico para a determinação quantitativa do ciprofloxacino (CIP) e do norfloxacino (NOR) em preparações farmacêuticas. Um método cromatográfico simples e rápido foi desenvolvido e validado para a determinação quantitativa de dois antibióticos fluoroquinolônicos em comprimidos e injetáveis. As quinolonas foram analisadas empregando-se uma coluna RP-18, LiChrospher® 100 (125 x 4 mm, 5µm) e fase móvel constituída por água:acetonitrila:trietilamina (80:20:0.3 v/v/v). O pH da mistura final foi ajustado a 3,3 com ácido fosfórico. A vazão da fase móvel foi de 1,0 mL/min e a detecção em UV a 279 nm. As análises foram realizadas à temperatura ambiente (24±2 ºC). O CIP e o NOR eluíram em menos de 5 min. As curvas de calibração foram lineares (r > 0.9999) na faixa de concentração entre 4,0 e 24,0 µg/mL. O desvio padrão relativo (RSD) foi < 1,0% e a recuperação média foi de 101,85%.

ABSTRACT - The objective of this research was to develop and validate an analytical method for quantitative determination of ciprofloxacin (CIP) and norfloxacin (NOR) in pharmaceutical preparations. A simple and rapid chromatographic method was developed and validated for quantitative determination of two fluoroquinolone antibiotics in tablets and injection preparations. The quinolones were analyzed by using a LiChrospher® 100 RP-18 column (5 µm, 125 x 4 mm) and a mobile phase consisted of water:acetonitrile:triethylamine (80:20:0.3 v/v/v). The pH of final mixture was adjusted to 3.3 with phosphoric acid. The flow rate was 1.0 mL/min and UV detection was made at 279 nm. The analyses were performed at room temperature (24 ± 2 ºC). CIP and NOR were eluted within 5 min. The calibration curves were linear (r > 0.9999) over a concentration range from 4.0 to 24.0 µg/mL. The relative standard deviation (RSD) was < 1.0% and the mean recovery was 101.85%.