Efficacy of ciprofloxacin and moxifloxacin against Nocardia brasiliensis in vitro and in an experimental model of actinomycetoma in BALB/c mice.

The efficacy of ciprofloxacin and moxifloxacin against Nocardia brasiliensis was evaluated by applying 25 mg of each drug/kg subcutaneously every 8 h in BALB/c mice infected with N. brasiliensis. A statistically significant difference was observed only with moxifloxacin. A moxifloxacin-trimethoprim-sulfamethoxazole combination was as active as when each compound was used alone.

A comparison of the performance of two chromatographic and three extraction techniques for the analysis of PAHS in sources of drinking water.

The aim of this work is to establish a sensitive and reliable method for the analysis of the 16 priority Environmental Protection Agency-defined polycyclic aromatic hydrocarbons (PAHs) found in water samples. Gas chromatography (GC)-mass spectrometry (MS) and high-performance liquid chromatography (HPLC)-fluorescence detection (FLD)-UV techniques are optimized to obtain an adequate resolution of all compounds. Validation of the methods is carried out, and a good performance is observed for both techniques. The HPLC-FLD-UV technique is somewhat more sensitive than the GC-MS technique for the determination of PAHs; thus, the HPLC-FLD-UV method is used to follow up both the solid-phase extraction (SPE) analysis using cartridges and discs and the liquid-liquid extraction (LLE), which are also evaluated for the extraction of the PAHs. Low recoveries between 43% and 79% are obtained using SPE cartridges, and higher values are obtained using SPE discs (56-96%) and LLE (60-105%). Better results are obtained using the LLE technique, and, thus, analysis of real water samples is carried out using this technique. LODs between 0.6 and 21 ng/L and relative standard deviations less than 15% are obtained using a spiked water sample analyzed using the full LLE HPLC-FLD-UV method.

Simultaneous determination and validation of antimicrobials in plasma and tissue of actinomycetoma by high-performance liquid chromatography with diode array and fluorescence detection.

A simple, precise, and reliable chromatographic method was developed for the simultaneous determination in plasma and infected tissue of five antimicrobials proposed for the treatment of actinomycotic mycetoma: amoxicillin, trimethoprim, linezolid, sulfamethoxazole and garenoxacin. Separation of the analytes was achieved on an Atlantis dC18 column (150 mm x 4.6 mm, ID 5 microm) with a mobile phase composed of acetonitrile and trifluoroacetic acid (ATF) 0.1% (v/v) using a gradient program. The detection was carried out using a diode array detector at 254 nm and in a fluorescence detector at wavelengths of excitation and emission of 292 nm and 392 nm for linezolid and sulfamethoxazole, and 292 nm and 408 nm for garenoxacin, respectively. The intraday precision was in the range of 0.7-15% of relative standard deviations (%R.S.D.) for plasma and 1-18% for tissue. Linearity range was from 2.4 to 20 microg/ml for amoxicillin, 0.3 to 20 microg/ml for trimethoprim, sulfamethoxazole and linezolid, and 0.3 to 10 microg/ml for garenoxacin. Acetonitrile was used to precipitate proteins from plasma. Recoveries in plasma ranged from 71% to 118% and in infected tissue from 78% to 122%. Limits of detection (LODs) were 1.2 and 0.5 microg/ml for amoxicillin in plasma and tissue, respectively and 0.15 and 1.2 microg/ml in plasma and tissue, respectively for the other antimicrobials. The method can be applied for individual or simultaneous determination of the antimicrobials in plasma and tissue of mouse infected with actinomycetoma.