Chemometrics-assisted spectroscopic methods for rapid analysis of combined anti-malarial tablets.

Combination of piperaquine (PQ) (320mg) and dihydroartemisinin (DHA) (40 mg) is an anti-malarial formulation, which is recommended by World Health Organization (WHO). Simultaneous analysis of PQ and DHA can be problematic due to the lack of chromophores or fluorophores in DHA molecule. Whereas PQ possesses strong UV absorption and it presents in 8 times of DHA contents in the formulation.

Development and applications of liquid chromatography-mass spectrometry for simultaneous analysis of anti-malarial drugs in pharmaceutical formulations.

The objective of this work was to develop a high-performance liquid chromatographic method coupled with a mass spectrometer (LC-MS) for the simultaneous analysis of artemisinin-based drugs (e.g. artemisinin, dihydroartemisinin, artesunate, artemether) and piperaquine in formulations.

Distance-based paper device using polydiacetylene liposome as a chromogenic substance for rapid and in-field analysis of quaternary ammonium compounds.

This work presents an affordable distance-based microfluidic paper-based device (μPAD), using polydiacetylene (PDA) liposome as a chromogenic substance with a smartphone-based photo editor, for rapid and in-field analysis of quaternary ammonium compounds (QACs) (e.g., didecyldimethylammonium chloride (DDAC), benzyldimethyltetradecyl ammonium chloride (BAC), and cetylpyridinium chloride (CPC)).

Paper-based sol-gel thin films immobilized cytochrome P450 for enzyme activity measurement.

Cytochrome P450 (CYP450), and in particular CYP3A4, is the most abundantly expressed CYP450 isozyme implicated in many drug-drug and medicinal plant-drug interactions. Therefore, incorporation of CYP3A4 enzyme screening at an early stage of drug discovery is preferable in order to avoid enzymatic interactions. Here we present for the first time a paper-based CYP3A4 immobilized sol-gel-derived a platform using resorufin benzyl ether as a fluorogenic enzyme substrate used to investigate enzyme activity.

Exosome aggregation mediated stop-flow paper-based portable device for rapid exosome quantification.

Exosome quantification is important for estimation of informative messengers (e.g., proteins, lipids, RNA, etc.

Recent applications of paper-based point-of-care devices for biomarker detection.

Detection of biomarkers is essential for diagnosis and prognosis of diseases for healthcare teams to provide timely appropriate treatments. Reliable, inexpensive, and sensitive devices are desirable to serve this purpose. Paper-based analytical devices (PADs) have gained enormous attention during the past decade as point-of-care devices for biomarker detection due to their simplicity, portability, and biocompatibility.

In-capillary derivatization with fluorescamine for the rapid determination of adamantane drugs by capillary electrophoresis with UV detection.

In-capillary derivatization using fluorescamine as the labeling reagent was proposed to enhance the detectability of adamantine drugs (memantine, amantadine and rimantadine) by spectrophotometric detection. Fluorescamine and the drugs were delivered to the capillary electrophoresis instrument at a ratio of 10:1 by zone injection. The derivatization reaction occurred following the application of voltage (20 kV).

Improved resolution of fluoroquinolones using cetyltrimethyl ammonium bromide-micellar electrokinetic chromatography and its application to residue analysis in surface water.

A simple micellar electrokinetic chromatography (MEKC), using cetyltrimethyl ammonium bromide (CTAB) as micelles, for the determination of ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR) and ofloxacin (OFL) residues in surface water was developed. Peak Master was used for predicting amounts of analyte ionic forms to reduce numbers of tedious experiments in optimizing the analyte capacity factors. A baseline separation (R > 2.

Brompheniramine as a novel probe for indirect UV detection and its application for the capillary electrophoresis of adamantane drugs.

Brompheniramine, an antihistamine drug, was employed as a novel UV probe for capillary electrophoresis with indirect UV detection of adamantane drugs (memantine, amantadine, and rimantadine). The probe possesses high molar absorptivity of 24 × 10 L/mol cm at 6 mM, which enables the measurement of these nonchromophore analytes without derivatization. The simple background electrolyte (10 mM sodium dihydrogen phosphate (pH 5.

Fluorescent labelling of ciprofloxacin and norfloxacin and its application for residues analysis in surface water.

Sensitivity enhancement for residue analysis of ciprofloxacin and norfloxacin in surface water was performed by liquid chromatography with fluorescent detection (LC-FD). Labelling of both drugs were studied with fluorescent probes (e.g.

Separation of dynorphin peptides by capillary electrochromatography using a polydiallyldimethylammonium chloride gold nanoparticle-modified capillary.

Dynorphin A (Dyn A) is an endogenous opioid peptide found in blood and central nervous system tissue at very low concentrations. Elevated levels of Dyn A due to different disease states, for example neurodegenerative disease, have been linked to toxic nonopioid activity. CE is a powerful technique that can achieve high-efficiency separations of charged analytes.

Evaluation of a Portable Microchip Electrophoresis Fluorescence Detection System for the Analysis of Amino Acid Neurotransmitters in Brain Dialysis Samples.

A portable fluorescence detection system for use with microchip electrophoresis was developed and compared to a benchtop system. Using this system, six neuroactive amines commonly found in brain dialysate (arginine, citrulline, taurine, histamine, glutamate, and aspartate) were derivatized offline with naphthalene-2,3-dicarboxaldehyde/cyanide, separated electrophoretically, and detected by fluorescence. The limits of detection for the analytes of interest were 50 - 250 nM for the benchtop system and 250 nM - 1.

Recent applications of microchip electrophoresis to biomedical analysis.

Many separation methods have been developed for biomedical analysis, including chromatographic (e.g. high performance liquid chromatography (HPLC) and gas chromatography (GC)) and electrophoretic methods (e.

Fast and Simultaneous Analysis of Combined Anti-Diabetic Drugs by Capillary Zone Electrophoresis.

A fast capillary zone electrophoretic method with photodiode array detection (CZE-PAD) was established and validated for assays of commonly prescribed anti-diabetic drugs [metformin (MET), glibenclamide (GBM) and gliclazide (GCZ)] in 13 samples including raw material, single and combined tablets. CZE optimization revealed baseline separation of the analytes (Rs > 5.39) in 8 min, in 50 mM borate buffer (pH 9.

Stability indicating MEKC method for the determination of gliclazide and its specified impurities.

A stability indicating-micellar electrokinetic chromatography method was developed and validated for the determination of gliclazide (GCZ) and its specified impurities, gliclazide impurities B (GZB) and F (GZF) in bulk and tablets. The analytes were well separated (Rs>2.1) in 5 min using 10mM phosphate buffer (pH 7.

Development and validation of an ion-exchange chromatography method for heparin and its impurities in heparin products.

An anion-exchange liquid chromatography method for the determination of heparin and its impurities (dermatan sulfate and oversulfated chondroitin sulfate) was developed using chemometric-assisted optimization, including multivariate experimental design and response surface methodology. The separation of heparin, dermatan sulfate, and oversulfated chondroitin sulfate (Rs above 2.0) was achieved on a Dionex RF IC IonPac AS22 column with a gradient elution of 10-70% of 2.

Simultaneous analysis of metformin and cyanoguanidine by capillary zone electrophoresis and its application in a stability study.

A capillary zone electrophoresis method was established for stability study of metformin (MET). MET and cyanoguanidine (CGN; a major degradation product) were well separated (with a resolution of 38.9) in 40 mM citrate buffer (pH 6.

Liquid chromatography and ion trap mass spectrometry for simultaneous and multiclass analysis of antimicrobial residues in feed water.

This work firstly reported the development of liquid chromatography coupled to an ion trap mass spectrometer (LC-MS ion trap) for the simultaneous determination of nitrofurans (e.g. nitrofurazone (NFZ), nitrofurantoin (NFT), furazolidone (FZD) and furaltadone (FTD)), nitroimidazoles (e.

Exploring chip-capillary electrophoresis-laser-induced fluorescence field-deployable platform flexibility: separations of fluorescent dyes by chip-based non-aqueous capillary electrophoresis.

Microfluidic chip electrophoresis (chip-CE) is a separation method that is compatible with portable and on-site analysis, however, only few commercial chip-CE systems with laser-induced fluorescence (LIF) and light emitting diode (LED) fluorescence detection are available. They are established for several application tailored methods limited to specific biopolymers (DNA, RNA and proteins), and correspondingly the range of their applications has been limited. In this work we address the lack of commercially available research-type flexible chip-CE platforms by exploring the limits of using an application-tailored system equipped with chips and methods designed for DNA separations as a generic chip-CE platform - this is a very significant issue that has not been widely studied.

Potential of capillary electrophoresis (CE) and chip-CE with dual detection (capacitively-coupled contactless conductivity detection (C4D) and fluorescence detection) for monitoring of nicotine and cotinine derivatization.

Capillary electrophoresis (CE) coupled with capacitively-coupled contactless conductivity (C(4)D) and fluorescence (FD) detectors and chip-CE for monitoring of nicotine and cotinine derivatization was demonstrated. Separation of the substrates and intermediates could be achieved by CE-C(4)D in 7 min (R(s) > 2.7) using 45 mM acetic acid (pH 3.

Rapid separations of nile blue stained microorganisms as cationic charged species by chip-CE with LIF.

Rapid detection of microorganisms by alternative methods is desirable. Electromigration separation methods have the capability to separate microorganisms according to their charge and size and laser-induced fluorescence (LIF) detection have single-cell detection capability. In this work, a new combined separation and detection scheme was introduced using chip-based capillary electrophoresis (chip-CE) platform with LIF detection.

Simultaneous analysis of biologically active pyridines in pharmaceutical formulations by capillary zone electrophoresis.

A capillary zone electrophoretic method using UV detection is developed for the analysis of four biological active pyridines [i.e., nicotine (NIC), cotinine (COT), nicotinic acid (NA), and nicotinamide (NM)].

Recent advances of capillary electrophoresis in pharmaceutical analysis.

This review covers recent advances of capillary electrophoresis (CE) in pharmaceutical analysis. The principle, instrumentation, and conventional modes of CE are briefly discussed. Advances in the different CE techniques (non-aqueous CE, microemulsion electrokinetic chromatography, capillary isotachophoresis, capillary electrochromatography, and immunoaffinity CE), detection techniques (mass spectrometry, light-emitting diode, fluorescence, chemiluminescence, and contactless conductivity), on-line sample pretreatment (flow injection) and chiral separation are described.

Rapid analysis of alkylphosphonate drugs by capillary zone electrophoresis using indirect ultraviolet detection.

A rapid capillary electrophoretic method for the analysis of three alkylphosphonate drugs (i.e. fosfomycin disodium (FOS), clodronate disodium (CLO) and alendronate sodium (ALN)) was developed by using multiple probe BGE and indirect UV detection.

A sensitive non-aqueous capillary electrophoresis-mass spectrometric method for multiresidue analyses of beta-agonists in pork.

Non-aqueous capillary electrophoresis-mass spectrometry (NACE-MS) was developed for trace analyses of beta-agonists (i.e. clenbuterol, salbutamol and terbutaline) in pork.