ABSTRACT
OBJECTIVE@#Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.@*METHODS@#The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.@*RESULTS@#The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.@*CONCLUSION@#The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.
Subject(s)
Chromatography, High Pressure Liquid , Liposomes , Magnetic Resonance Spectroscopy , TaxoidsABSTRACT
Objective To investigate a cure for neonatal hypoxic-ischemic encephalopathy(HIE) by observing the curative effect on neonates with HIE admitted to neonatal intensive care unit (NICU).Methods Fifty neonates with HIE from May to Dec.in 2006 admitted to NICU for treatment(NICU group),which contrast to the 42 neonates with HIE in corresponding periods of 2005 year(control group).The curative effect of three supports and three expectant treatment were evaluated by observing vital signs,oxygen saturation,biochemical test,and the neonatal beha-vioral nerve assessment (NBNA) respectively; Clinical curative effect contained markedly effective and effective which as the total curative effect statistics.Results There were no obvious difference between each group from the means of blood sugar data while hospitalizing as well as the NBNA in 3 days. By contrast, the blood sugar status and NBNA improving of neonates with HIE admitted to NICU surpassed the control group after treatment (Pa