High performance liquid chromatography determination of prulifloxacin and five related impurities in pharmaceutical formulations.

A novel HPLC method for the simultaneous determination of Prulifloxacin, Ulifloxacin, its process impurities in a tablets formulation and Enrofloxacin, used as Internal Standard, is developed. The separation was successfully carried out with a new stationary phase, HILIC, under isocratic elution mode using ammonium acetate buffer (5 mM, pH 5.8) and acetonitrile (12:88, v/v) at a flow rate of 1.0 mL/min. Column was thermostated at 25 °C (±1 °C) and 20 µL were injected for the analysis. Calibration curves were linear in the investigated range with correlation coefficient better than 0.9880, while the limit of quantifications ranged from 0.25 to 5 µg/mL, depending from the analyte. The within and between batch precision (RSD%) values ranged from 0.11% to 13.9% while within and between batch trueness (bias%) values ranged from 14.0% to -11.3%. This method for the direct determination and quantification of process impurities in pharmaceutical formulations is suitable for routine analyses in quality control laboratories and was applied to evaluate for the first time, the presence and the quantities of cited analytes in commercially available formulation.

A unique microRNA signature associated with plaque instability in humans.

BACKGROUND AND PURPOSE: Atherosclerotic plaque rupture is considered the most important mechanism that underlies the onset of stroke, myocardial infarction, and sudden death. Several evidences demonstrated the pivotal role of inflammatory processes in plaque destabilization. MicroRNAs (miRNAs) are small endogenous RNAs and represent a new important class of gene regulators. Nevertheless, no data exist about the expression profile of miRNAs in atherosclerotic plaques. Thus, the aim of this study was to investigate the expression level of miRNAs in human plaques and to correlate it with clinical features of plaque destabilization. METHODS: Two separate groups of plaques were collected from patients who underwent carotid endarterectomy in Chieti (n=15) and Ancona (n=38) Hospitals. All the plaques were subdivided in symptomatic (n=22) and asymptomatic (n=31) according to the presence/absence of stroke. RESULTS: First, on the plaques collected at Chieti Hospital, we performed large-scale analysis of miRNA expression. Between the 41 miRNAs examined, we discovered profound differences in the expression of 5 miRNAs (miRNA-100, miRNA-127, miRNA-145, miRNA-133a, and miRNA-133b) in symptomatic versus asymptomatic plaques. Remarkably, when we repeated the analysis on the Ancona plaque subset, all these 5 miRNAs confirmed to be significantly more expressed in the symptomatic plaques. Finally, in vitro experiments on endothelial cells transfected with miRNA-145 and miRNA-133a confirmed the importance of these miRNAs in the modulation of stroke-related proteins. CONCLUSIONS: These results are the first to report alterations in the expression of specific miRNAs in human atherosclerotic plaques and suggest that miRNAs may have an important role in regulating the evolution of atherosclerotic plaque toward instability and rupture. Furthermore, by identifying the specific miRNA signature for stroke now, we are able to use computer algorithms to identify previously unrecognized molecular targets.