Development of an Aseptic Urine Collection Kit and its Evaluation in Preventing the Bacterial Decomposition of Nitrazepam

Abstract

A novel aseptic urine collection kit has been devised, and its effectiveness in collecting and storing bacteria-free urine specimens was evaluated. The kit, which is based on filtration sterilization, was proven effective for these purposes. For the evaluation of its efficiency, urine samples spiked with nitrazepam at 0.5 µg/ml were treated with the kit and monitored for 6 months at 4°C and 25°C. An automated column-switching liquid chromatography-mass spectrometry (LC-MS) procedure was utilized for the direct determination of the analyte in urine. In severelycontaminated urine with bacteria, there were significant losses of nitrazepam at 25°C. However, such degradation was successfully suppressed by the use of the kit even at a storage temperature of 25°C, while requiring no chemical additives.

Long-term stability of various drugs and metabolites in urine, and preventive measures against their decomposition with special attention to filtration sterilization

“…In our previous study [8], the bacterial contamination levels (i.e., numbers of bacterial cells) in random urine specimens submitted to our laboratory (n = 24) were examined using the LB (Luria-Bertani) media [13]. The effectiveness of the aseptic urine collection kit in removing bacteria and keeping bacteria-free samples was also evaluated.…”

“…We primarily investigated the long-term stability of these drugs/metabolites in urine at low concentrations, with special attention to the efficiency of a newly invented aseptic urine collection kit. The kit has been devised to aseptically collect urine samples based on filtration sterilization [8]. To accurately and efficiently analyze a large number of samples containing unstable drugs/metabolites toward hydrolysis, an automated column-switching liquid chromatography-mass spectrometry (LC-MS) procedure was established and utilized for the simultaneous determination of these analytes in urine, based on our previous studies [9][10][11].…”