Development and validation of a sensitive enantiomeric separation method for new single enantiomer drug levornidazole by CD-capillary electrophoresis

Ornidazole-Induced Recurrent Encephalopathy in a Chinese Man: A Rare Case Report and Literature Review

Ornidazole-induced encephalopathy (OIE) is seldom seen in the clinic. In this study, we report a new case of a patient who had taken 1,000 mg ornidazole daily for nearly 4 years because of suspected diarrhea and proctitis and presented with subacute symptoms such as unsteady gait, slurred speech, and psychiatric disorder. These symptoms were significantly relieved 3 days after the patient stopped taking ornidazole. When he took this medicine again, however, similar symptoms occurred 4 months later, which were again reduced after 4 days of drug discontinuation. After the second onset, abnormal signals were identified around the aqueduct of the midbrain, around the fourth ventricle, and in the dentate nuclei of the cerebellum bilaterally. After 9 days of drug discontinuation, lesions disappeared in the magnetic resonance imaging (MRI) results. According to the clinical manifestations, imaging features, and the reduced symptoms after drug withdrawal, we clinically diagnosed the patient with OIE. This paper also reviews the literature on OIE. Only five cases (including our case) have been reported, all of whom presented with cerebellar ataxia and dysarthria and three with additional mental symptoms such as agitation and irritability. All five patients had abnormal lesions in the dentate nucleus of the cerebellum bilaterally, among whom four also had lesions in the corpus callosum and three around the periaqueduct of the midbrain. After withdrawal of ornidazole, the symptoms in all patients vanished or were alleviated, and three of them showed reduced or disappeared lesions in a head MRI reexamination. Overall, OIE has rarely been reported. Our case report and literature review show that the lesions in the cerebellum, corpus callosum, and brainstem can be reversed. The main manifestations of the lesions—cerebellar ataxia, dysarthria, and mental symptoms—quickly weaken or disappear after drug withdrawal, with good prognosis. Nevertheless, clear pathogenesis has yet to be further investigated.

Enantiomeric Determination of Drugs in Pharmaceutical Formulations and Biological Samples by Electrokinetic Chromatography

Chirality is a relevant issue in the pharmaceutical field due to the different biological activity that enantiomers of a chiral drug can show. In fact, the desired biological or pharmaceutical activity might be present in only one of the enantiomers, while the other enantiomer(s) may have different biological activity, be inactive or even toxic. This has motivated in recent years the development of drugs marketed as pure enantiomers to avoid exposing the organism to the action of enantiomers that may not be active or even harmful to health. Thus, it is of high interest to develop enantioselective analytical methodologies to control the presence of enantiomeric impurities and to understand the enantioselective metabolism of chiral drugs. This review gives an overview about the analytical strategies developed by electrokinetic chromatography (EKC) from 2010 to June 2019 for the enantiomeric determination of drugs in both pharmaceutical formulations and biological samples. The types of chiral selectors used, the migration order of enantiomers, their resolution, the detection technique employed and the sensitivity achieved are revised and compared. Also, applications to assess the enantiomeric purity control of pharmaceutical formulations and to determine chiral drugs in biological samples to study their metabolism are included. Advantages and limitations of the chiral methods developed by EKC are also discussed.

Clinical and pharmaceutical applications of affinity ligands in capillary electrophoresis: A review

Affinity capillary electrophoresis (ACE) is a separation technique that combines a biologically-related binding agent with the separating power and efficiency of capillary electrophoresis. This review will examine several classes of binding agents that have been used in ACE and applications that have been described for the resulting methods in clinical or pharmaceutical analysis. Binding agents that will be considered are antibodies, aptamers, lectins, serum proteins, carbohydrates, and enzymes. This review will also describe the various formats in which each type of binding agent has been used in CE, including both homogeneous and heterogeneous methods. Specific areas of applications that will be considered are CE-based immunoassays, glycoprotein/glycan separations, chiral separations, and biointeraction studies. The general principles and formats of ACE for each of these applications will be examined, along with the potential advantages or limitations of these methods.

Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis

Since the introduction about 30 years ago, CE techniques have gained a significant impact in pharmaceutical analysis. The present review covers recent advances and applications of CE for the analysis of pharmaceuticals. Both small molecules and biomolecules such as proteins are considered. The applications range from the determination of drug-related substances to the analysis of counterions and the determination of physicochemical parameters. Furthermore, general considerations of CE methods in pharmaceutical analysis are described.

Cyclodextrins in capillary electrophoresis: recent developments and new trends

Despite the fact that extensive research in the field of separations by capillary electrophoresis (CE) has been carried out and many reviews have been published in the last years, a specific review on the use and future potential of cyclodextrins (CDs) in CE is not available. This review focuses the attention in the CD-CE topic over the January 2013-February 2014 period (not covered by previous more general CE-reviews). Recent contributions (reviews and research articles) including practical uses (e.g. solute-CD binding constant estimation and further potentials; 19% of publications), developments and applications (mainly chiral and achiral analysis; 38 and 24% of publications, respectively) are summarized in nine comprehensive tables and are commented. Statistics and predictions related to the CD-CE publications are highlighted in order to infer the current and expected research interests. Finally, trends and initiatives on CD-CE attending to real needs or practical criteria are outlined.