DIRECT AND DERIVATIVE SPECTROPHOTOMETRIC ESTIMATION OF GEMIFLOXACINMESYLATE BY CHELATION WITH Cr (III) ION

Authors: D.Madhuri*1, K.B.Chandrasekhar1, N.Devanna1 and G.Somasekhar2

1Department of Chemistry, JNTUniversity, Anantapur A.P. INDIA; 2 Department of Pharmacy, Omer-Al-Mukhtar University, LIBYA; *Email:madhuri.pharma@redifmail.com

A simple, sensitive and accurate spectrophotometric method was described for the determination of Gemifloxacin mesylate (GFX) a broad spectrum flouroquinolone anti bacterial  either  in pure form or in the tablet .The method is based on chelate formation between GFX and Chromium(Cr III) in aqueous media. The complex showed an absorption maximum at 545nm for zero order ,Ist derivative at 620nm and Second derivative at 660nm respectively with apparent molar absorpitivities of 1.07x10 ⁴  L-M^-1Cm^-1,^, 7.01x10³ L-M^-1Cm^-1 for Ist order derivative, 1.04x10 ⁴  LM^-1Cm^-1 for 2^nd order derivative  respectively. The solution of the complex obeyed beer’s law in the concentration range of 2to 20µg/ml for zero order,1 to15 µg/ml  for Ist order and 1to 25  µg/ml  for 2^nd order respectively. The limit of detection and Limit of quantification were calculated and RSD were less than 0.2866.The chelate composition between GFX and Cr(III) ion was found to be 1:1 ratio determined by Job’s continuous method and by Molar ratio method. The proposed method was applied for the determination of GFX in tablets without interference from common excipients .The results obtained by the application of this procedure showed percentage recoveries were 99.9±0.1463 for zero order , 100.2±0.1065 for Ist order and 100.6±0.1589 for 2^nd order respectively.

Keywords : Flouroquinolone, Gemifloxacin mesylate, Chelate, Aqueous media, Spectrophotometric Pharmaceutical formulation.