Photodegradation of sparfloxacin and isolation of its degradation products by preparative HPLC

Sparfloxacin, a third generation fluoroquinolone derivative, is a potent antibacterial agent active against a wide range of Gram-positive and Gram-negative organisms including Streptococcus pneumoniae, Staphylococcus aureus, methicillin resistant S. aureus, Legionella spp., Mycoplasma spp., Chlamydia spp. and Mycobacterium spp. A drawback of fluoroquinolones is their photoreactivity. Sparfloxacin has been studied in terms of therapeutic activities. However, there are few published of analytical methods being applied to sparfloxacin. The aim in this study was to determine the photodegradation products of sparfloxacin, when submitted to UV light, and to characterize two of these products, designated SPAX-PDP1 and SPAX-PDP2. An accelerated study of stability in methanol solution was carried out by exposing a solution of sparfloxacin to UV light (peak wavelength 290 nm) for 36 hours at room temperature. The products were analyzed by NMR spectrophotometry, IR spectrometry and mass spectrophotometry. The results suggest that the products isolated here could be used to estimate the degradation of sparfloxacin in a stability study. However, the low activity exhibited by UV-irradiated sparfloxacin is a source of concern that demands further investigation of the mechanism of its photodegradation mechanism

Análise térmica de esparfloxacino / Thermal analysis of sparfloxacin

Foi realizada a análise térmica de esparfloxacino, fluorquinolona de terceira geração que possui potente atividade contra bactérias Gram-positivas, como Streptococcus pneumoniae e Staphylococcus aureus inclusive cepas meticilina resistentes (MRSA), bactérias Gram-negativas, anaeróbios, Legionella spp., Mycoplasma spp., Chlamydia spp. e Mycobacterium spp. Nas curvas DTA observa-se pico endotérmico de fusão na temperatura de 276,5ºC. A curva DTA, em ar sintético, apresenta dois picos exotérmicos (341,6 e 579,2ºC), atribuídos à decomposição do composto. A curva TG permite observar a perda de massa total em duas etapas, entre as temperaturas de 285,5 e 645,3ºC. A curva DTA, em atmosfera de nitrogênio, apresenta pico exotérmico de decomposição na temperatura de 340,0ºC e na curva TG, a perda de massa inicia-se na temperatura de 254,4º