%0 Journal Article %T Spectrophotometric Determination of Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes %A Ayman A. Gouda %A Alaa S. Amin %A Ragaa El-Sheikh %A Amira G. Yousef %J Journal of Analytical Methods in Chemistry %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/286379 %X Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422£¿nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beer¡¯s law was obeyed in the ranges 1.0¨C30, 1.0¨C20, and 2.0¨C24£¿¦Ìg mL£¿1 for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision. 1. Introduction Fluoroquinolones are the second-generation members of quinolone antibiotics fluorinated in position 6 and bearing a piperazinyl moiety at position. They are considered to be the most effective Gram-positive and Gram-negative pathogens to combat infection caused by microorganisms that are resistant to other microbials, such as tetracyclines. Also, they have some activity against mycobacteria, mycoplasmas, rickettsias, and the protozoan Plasmodium falciparum [1¨C3]. There is a substantial body of literature related to both the mechanism of their action as DNA gyrase inhibitors and the influence of systematic structural modifications on their biological activity. Gemifloxacin mesylate (GMF) is (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate. Moxifloxacin (MXF) is {1-cyclopropyl-7-[2,8-diazobicyclo (4.3.0) nonane]-6-fluoro-8-methoxy-1,4 dihydro-4-oxo-3-quinolone carboxylic acid}. Enrofloxacin (ENF) is (1 cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolone carboxylic acid) (Scheme 1). GMF and MXF are fourth-generation synthetic broad-spectrum 8-methoxy fluoroquinolone antibacterial drug derivatives. Due to their clinical advantages, GMF and MXF %U http://www.hindawi.com/journals/jamc/2014/286379/