Gemifloxacin mesylate

USAN Gemifloxacin mesylate Trade name Factive ... 

Gemifloxacin mesylate is freely soluble in water at neutral, pH 7.0. Its water solubility has been reported (http //www.rxlist.com/factive-drug. htm) as 350 mg/ml at 25 °C. It is soluble in methanol, 0.1 N hydrochloric acid and 0.1 N sodium hydroxide solutions. 

The ultraviolet absorption spectra of gemifloxacin mesylate were recorded on A Shimadzu UV-1601 PC double beam spectrophotometer with matched 1-cm quartz cells in water, methanol, 0.1 N hydrochloric acid, and 0.1 N sodium hydroxide solutions. Figure 4.1 shows the recorded absorption spectra of these solutions. The recorded spectra were essentially identical and exhibiting two peak maxima for each spectrum at 266 and 340, 272 and 342,272 and 344, and 262 and 342 nm for the solutions in water, methanol, 0.1 N hydrochloric acid and 0.1 N sodium hydroxide, respectively. The molar absorptivity of gemifloxacin mesylate was found to be moderately affected by the solvent used. The calculated molar absorptivity in water, methanol, 0.1 N hydrochloric acid, and 0.1 N sodium hydroxide solutions at the two maxima was tabulated in Table 4.1. However, the position of the maxima, as compared to water, was slightly red shifted for methanol and 0.1 N hydrochloric acid solutions and slightly blue shifted for 0.1 N sodium hydroxide solution. 

Gemifloxacin mesylate was found to be very strongly fluorescent when dissolved in water and moderately fluorescent in 0.1 N hydrochloric acid and 0.1 N sodium hydroxide (the fluorescence intensity of gemifloxacin mesylate in 0.1 N HCl was about twofolds more than that of 0.1 N NaOH). 

FIGURE 4.1 The ultraviolet absorption spectra of 10 ppm gemifloxacin mesylate in water (1), 0.1 N sodium hydroxide (2), 0.1 N hydrochloric acid (3), and methanol (4) solutions. 

Spectrofluorimeter, Kontron SFM 25 equipped with a 150-W xenon high-pressure lamp was used for recording the fluorescence spectrum of gemifloxacin mesylate in water. As shown in Fig. 4.2, the fluorescence spectrum exhibited two excitation maxima at 266 and 342 nm and one emission maximum at 391 nm. The fluorescence intensity obtained at l x 266 nm was found to be more (5-25% depending on the solvent used) than that obtained at 342 nm. Moreover, the position of the emission maximum was red shifted in 0.1 N HCl solution (405 nm) and blue shifted in 0.1 N NaOH solution (390 nm). 

The infrared absorption spectrum of gemifloxacin mesylate was recorded on FT-IR model Spectrum BX spectrophotometer (Perkin-Elmer, USA) using a KBr disc ( 2 mg of gemifloxacin mesylate was dispersed in 200 mg KBr). The obtained infrared spectrum is shown in Fig. 4.3, and the assignments of the characteristic bands are tabulated in Table 4.2. 

FIGURE 4.2 The excitation (1) and emission spectra (2, 3) of aqueous solution of gemifloxacin mesylate (2 ppm). The emission spectra (2) and (3) were obtained at excitation wavelength of 266 and 342 nm, respectively. 

The NMR absorption spectrum of gemifloxacin mesylate was recorded on a Bruker-Ultra Shield spectrometer (Bruker Co., USA) at 500 MHz in deuterated water. The obtained NMR spectrum is shown in Figs. 4.4 and 4.5, and the assignments of the observed bands are tabulated in Table 4.3. The four protons of the hydroxyl and amino groups are disappeared in deuterated water. 

The gas chromatography-mass spectrum of gemifloxacin mesylate is presented in Fig. 4.6, and the assignments for the main observed fragments are tabulated in Table 4.4. 

Gemifloxacin mesylate in 0.1 N sodium hydroxide solution was determined in our laboratory using UV spectrophotometry at 342 nm in bulk and its pharmaceutical preparations. Beer s law was obeyed in the concentration range 2.0-20.0 gg/ml at 342 nm, respectively. 

Gemifloxacin mesylate was oxidized with Fe (111) and determining Fe(ll) produced from the oxidation process by its chelation with either 1,10-phe-nanthroline, 2,2 -bipyridyl, or ferricyanide at 515, 520, and 760 nm. 

FIGURE 4.4 H NMR spectrum of gemifloxacin mesylate (at 500 MHz) in deuterated water. 

TABLE 4.4 Gas chromatography mass spectral data of gemifloxacin mesylate... 

Gemifloxacin mesylate The proposed methods were based on the reaction of gemifloxacin with chloranilic add and parachloranil to give highly coloured complexes. The coloured products were quantified spectrophotometrically at 530 nm and 540 nm at zero order, 590 and 610 nm for the first derivative and 630 and 650 nm for second order derivative. Beer s law was obeyed in the concentrations range of 10 to 60 pg mL-i, 5 to25 pg mL-i at zero order, 5 to 25 pg mL-i, 5 to 40 pg mL-i at first order and 2 to 20 pg mL-i and 2 to 14 pg mL-i at second order. 17... 

Hyun, M.H. Han, S.C. Cho, Y.J. Jin, J.S. Lee, W. Liquid chromatographic resolution of gemifloxacin mesylate on a chiral stationary phase derived from crown ether, Biomed.Chromatogr., 2002, 16,... 

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