Etimicin Sulfate

Etimicin is a typical aminoglycoside antibiotic (AG). High performance liquid chromatography-evaporation light scattering detector (HPLC-ELSD) method is a commonly used method for determining impurities in Etimicin. However, due to the poor reproducibility, low sensitivity and narrow linear range of the ELSD, high-throughput quantitative analysis of impurities in Etimicin currently poses a challenge. In this study, a sensitive method using hydrophilic interaction liquid chromatography coupled with charged aerosol detector (HILIC-CAD) was developed for the analysis of the impurities in Etimicin. The liquid phase conditions for determination impurities in Etimicin were optimized using Box Behnken design (BBD) and response surface methodology (RSM), resulting in satisfactory separation and optimal CAD output signal. We also studied the influence of CAD parameters on the signal-to-noise ratio and linearity of Etimicin and its impurities. This method has also been proven to be effective in separating impurities from two other typical AGs, Isepamicin and Amikacin. In the method validation, the coefficient of determination (R²) of Etimicin, Isepamicin and Amikacin and their impurities were all greater than 0.999, within the range of 0.5-50 μg/mL. The average recoveries of the impurities of three typical AGs were 99.03 %-101.22 %, RSDs all were less than 2.5 % for intra-day and inter-day precision, with good precision and accuracy. The developed HILIC-CAD quantification method was sensitive, accurate and highly selective for quantitative analysis of impurities in the AGs without need ion-pairing reagents, which is ensure the public medication safety. The method is first reported application of HILIC-CAD method for quantitative analysis of the impurities in AGs.

Rhodococcus equi, predominantly recognized as an opportunistic pathogen affecting immunocompromised hosts, and Brucella, a widespread zoonotic bacterium, infrequently co-infect immunocompetent adults, thereby posing a distinctive diagnostic challenge. Here, we describe a case involving a 53-year-old male with a history of goat farming, who presented with persistent chest tightness, cough, and notable weight loss, absent fever. Radiological and bronchoscopic assessments showed a right hilar mass, extensive vertebral destruction, and bronchial lesions, deviating from the typical symptoms associated with either pathogen. Laboratory analyses confirmed a co-infection involving R. equi and Brucella. Initial therapy with levofloxacin and vancomycin proved ineffective; however, a subsequent treatment regimen comprising azithromycin, etimicin, minocycline, and moxifloxacin resulted in substantial clinical improvement. This case accentuates the intricacies involved in diagnosing and managing atypical co-infections in immunocompetent individuals and underscores the importance of careful microbiological testing to inform effective therapeutic strategies.