Erratum to: UPLC versus HPLC on Drug Analysis: Advantageous,Applications and Their Validation Parameters

Liquid chromatography (LC) is a separation technique used in many different areas to aid the identification and quantification of substances in various matrices. LC techniques with various detection modes have been widely used for the sensitive and selective determination of trace amounts of pharmaceutical active compounds in biological samples and their dosage forms. A completely new system design with advanced technology has been developed, called ultra high performance liquid chromatography, which has evolved from high performance liquid chromatography. The application of LC methods to drug analysis introduces a powerful tool for therapeutic drug monitoring as well as for clinical research. The advantages of short turnaround time, method reliability, method sensitivity, and drug specificity justify the use of LC techniques for various groups of the drug active compounds. This review describes some of the principles of ultra high performance liquid chromatography and high performance liquid chromatography, validation of these methods, system suitability tests for the methods, and application of methods to pharmaceutical analysis in the last 3 years.

     

The application of sub-2-microm particle liquid chromatography-operated high mobile linear velocities coupled to orthogonal accelerated time-of-flight mass spectrometry for the analysis of ranitidine and its impurities

Impurity profiling of pharmaceutical drug substances or dosage formulations require methods involving high sensitivity and resolution from LC and MS alike as well as an acceptable analysis time. While throughput can be increased, it is usually at the expense of chromatographic resolution. The application of sub-2-microm stationary phases and high mobile linear velocities has been combined with orthogonal acceleration (oa)-TOF MS for the impurity structural characterization analysis of small-molecule pharmaceutics. A pharmaceutical drug substance was forcefully degraded and used to test the proof of concept of developing an impurity profile method by ultra performance liquid chromatography (UPLC). Optimum conditions were identified by use of method development simulation software as well as traditional approaches of method scouting with columns and a varied range of pH. Further analysis illustrated the effectiveness of applying oa-TOF MS techniques to assist in achieving exact mass coupled with MS/MS to define the structural characterization of the related substances relative to the pharmaceutical active ingredient and identification of any unknown impurity substances. The barriers with trade-offs between resolution and speed are overcome by the application of UPLC, whereas the increased sensitivity provides for superior exact mass oa-TOF MS.     

Profiling of grape monoterpene glycosides (aroma precursors) by ultra‐high performance‐liquid chromatography‐high resolution mass spectrometry (UHPLC/QTOF)

A ‘suspect screening analysis’ method for grape metabolomics by ultra‐high performance‐liquid chromatography (UHPLC) and high‐resolution quadrupole‐time of flight (QTOF) mass spectrometry was recently developed. This method was applied to study grape monoterpene glycosides, the main grape aroma precursors. Since standard compounds were not available, they were tentatively identified by overlapping various analytical approaches, in agreement with the indications recommended in mass spectrometry (MS)‐based metabolomics. Accurate mass and isotopic pattern, MS/MS fragmentation, correlation between fragments observed and putative structures and between liquid chromatography coupled with mass spectrometry (LC/MS) and gas chromatography/mass spectrometry signals were studied. Seventeen monoterpene glycosides were identified without performing the hydrolytic artifacts commonly used to study these compounds which may affect sample profile. This is the first time that a detailed study of these aroma precursors has been carried out by direct LC/MS analysis. Copyright © 2014 John Wiley & Sons, Ltd.     

Recent developments in the HPLC separation of phenolic compounds

Phenolic compounds represent a class of highly complex naturally occurring molecules that possess a range of beneficial health properties. As a result, considerable attention has been devoted to the analysis of phenolics in a variety of samples. HPLC is the workhorse method for phenolic separation. However, conventional HPLC methods provide insufficient resolving power when faced with the complexity of real-world phenolic fractions. This limitation has been traditionally circumvented by extensive sample fractionation, multiple analysis methods and/or selective detection strategies. On the other hand, there is an increasing demand for improved throughput and resolving power from the chromatographic methods used for phenolic analyses. Fortunately, during the last decade, a number of important technological advances in LC have demonstrated significant gains in terms of both speed and resolution. These include ultra high-pressure liquid chromatography (UHPLC), high-temperature liquid chromatography (HTLC), multi-dimensional separations as well as various new stationary phase chemistries and morphologies. In recent years, these technologies have also found increasing application for phenolic analysis. This review seeks to provide an updated overview of the application of recent advances in HPLC to phenolic separation, with the emphasis on how these methodologies can contribute to improve performance in HPLC analysis of phenolics.     

Screening and analysis of potentially active components in Shenxiong glucose injection using UHPLC coupled with photodiode array detection and MS/MS

Shenxiong glucose injection, a pharmaceutical preparation containing a water extract of the roots of Salvia miltiorrhizae and ligustrazine hydrochloride, is widely used in clinical to treat cardiovascular diseases in China. The chemical components of the water extract have been reported and the cardioprotective effects of the injection have been evaluated. However, the chemical constituents of the injection and their correlations with its pharmacological effects have not been established. In this study, 13 chemical constituents of the injection have been identified or characterized by ultra‐high performance liquid chromatography with diode array detection and electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry. Besides, the potentially active compounds of this preparation that directly act on cardiac cells have been screened by cell extraction and ultra high performance liquid chromatography targeted multiple reaction monitoring. As a result, eight potentially active compounds, danshensu ( 1 ), ligustrazine hydrochloride ( 4 ), salvianolic acid I/H ( 7 ), lithospermic acid ( 8 ), salvianolic acid D ( 9 ), rosmarinic acid ( 10 ), salvianolic acid B ( 12 ), and salvianolic acid C ( 13 ), were obtained and structurally characterized from the 11 target compounds used for screening. The liquid chromatography with quadrupole time‐of‐flight mass spectrometry and liquid chromatography with multiple reaction monitoring tandem mass spectrometry combination method has demonstrated its potency for the screening, detection, and structural identification of bioactive compounds in a complex matrix.     

Rapid Screening of Volatile Ion-Pair Reagents Using UHPLC and Robust Analytical Method Development Using DoE for an Acetyl Cholinesterase Inhibitor: Galantamine HBr

As over 70% of pharmaceutical compounds are bases, the analysis of these basic compounds by high performance liquid chromatography (HPLC) continues to be of great value and interesting. Acetyl cholinesterase inhibitors (AChEIs), which contain the basic compounds like Rivastigmine tartrate, Galantamine hydrobromide and Donepezil with different polarities, were chosen for the study. A rapid screening of the volatile ion-pairing reagents was performed using modern techniques like ultra high performance liquid chromatography (UHPLC). The experiments were planned using the ??Design of Experiments?? (DoE) approach to identify the LC?CMS compatible ion-pair reagent. In this study, Heptafluorobutyric acid (HFBA) has given a very good peak shape with tailing factor at 1.4 and theoretical plates up to ~5,000 were observed, compared to tailing factor at 1.9 and theoretical plates up to ~3,000 with non-volatile ion-pair reagent sodium heptane sulphonate (SHS). Similarly retention with HFBA was optimum as ~5 min in short run time method compared to ~13 min with SHS. This ion-pair reagent has proved to be good replacement of sodium alkyl sulphonate modifiers. HFBA can also be used for semi-preparative work for isolation of impurities by just evaporating the solvents. It avoids the extraction of other inorganic modifiers.     

Recent advances of online coupling of sample preparation techniques with ultra high performance liquid chromatography and supercritical fluid chromatography

Ultra high performance liquid chromatography and supercritical fluid chromatography techniques are favored because of their high efficiency and fast analysis speed. Although many sample preparation techniques have been coupled with common liquid chromatography online, the online coupling of sample preparation with the two popular chromatography techniques have gained increasing attention owing to the increasing requirements of efficiency and sensitivity. In this review, we have discussed and summarized the recent advances of the online coupling of sample preparation with ultra high performance liquid chromatography and supercritical fluid chromatography techniques. The main sample preparation techniques that have been coupled with ultra high performance liquid chromatography online are solid‐phase extraction and in‐tube solid‐phase microextraction, while solid‐phase extraction and supercritical fluid extraction are the main techniques that have been coupled with supercritical fluid chromatography online. Especially, the strategies for online coupling of sample preparation with chromatography techniques were summarized. Typical applications and growing trends of the online coupling techniques were also discussed in detail. With the increasing demands of improving the efficiency, throughput, and analytical capability toward complex samples of the analysis methods, online coupling of sample preparation with chromatography techniques will acquire further development.     

LC with Electrochemical Detection. Recent Application to Pharmaceuticals and Biological Fluids

Many pharmaceutical compounds have electroactive groups and are readily measurable and detectable by liquid chromatography with electrochemical detection (LC–EC). LC–EC techniques have many advantages as measurement systems and new materials have been developed for working electrodes. Use of modern electroanalytical techniques for detection in LC of pharmaceutical compounds is discussed in this review. EC detection in LC often results in improved selectivity and detection limits for electroactive pharmaceutical compounds. Selected literature on the determination of pharmaceutical compounds in their dosage forms and in biological samples are reported.     

Microfluidic chip-based liquid chromatography coupled to mass spectrometry for determination of small molecules in bioanalytical applications

The development and integration of microfabricated liquid chromatography (LC) microchips have increased dramatically in the last decade due to the needs of enhanced sensitivity and rapid analysis as well as the rising concern on reducing environmental impacts of chemicals used in various types of chemical and biochemical analyses. Recent development of microfluidic chip-based LC mass spectrometry (chip-based LC-MS) has played an important role in proteomic research for high throughput analysis. To date, the use of chip-based LC-MS for determination of small molecules, such as biomarkers, active pharmaceutical ingredients (APIs), and drugs of abuse and their metabolites, in clinical and pharmaceutical applications has not been thoroughly investigated. This mini-review summarizes the utilization of commercial chip-based LC-MS systems for determination of small molecules in bioanalytical applications, including drug metabolites and disease/tumor-associated biomarkers in clinical samples as well as adsorption, distribution, metabolism, and excretion studies of APIs in drug discovery and development. The different types of commercial chip-based interfaces for LC-MS analysis are discussed first and followed by applications of chip-based LC-MS on biological samples as well as the comparison with other LC-MS techniques.     

Recent development trends for chiral stationary phases based on chitosan derivatives,cyclofructan derivatives and chiral porous materials in high performance liquid chromatography

The separation of enantiomers by chromatographic methods, such as gas chromatography, high‐performance liquid chromatography and capillary electrochromatography, has become an increasingly significant challenge over the past few decades due to the demand of pharmaceutical, agrochemical, and food analysis. Among these chromatographic resolution methods, high‐performance liquid chromatography based on chiral stationary phases has become the most popular and effective method used for the analytical and preparative separation of optically active compounds. This review mainly focuses on the recent development trends for novel chiral stationary phases based on chitosan derivatives, cyclofructan derivatives, and chiral porous materials that include metal‐organic frameworks and covalent organic frameworks in high‐performance liquid chromatography. The enantioseparation performance and chiral recognition mechanisms of these newly developed chiral selectors toward enantiomers are discussed in detail.     

Compatibility of sildenafil citrate and pharmaceutical excipients by thermal analysis and LC–UV

The evaluation of sildenafil citrate (SC), the best-selling drug for treatment of impotence, for compatibility with various excipients was investigated using thermal and isothermal stress testing. Differential scanning calorimetry (DSC), hot-stage microscopy (HSM) and liquid chromatography (LC) with ultraviolet detection were successfully employed to investigate the compatibility between SC and various excipients commonly used in solid form in the pharmaceutical industry. The studies were performed using 1:1 (m/m) drug/excipient physical mixtures and samples were stored under accelerated stability conditions (40 °C at 75% relative humidity). All excipients tested (such as colloidal silicon dioxide, croscarmellose sodium, lactose, mannitol and sucrose) showed potential incompatibilities by DSC and LC analysis after accelerated stability testing. However, some incompatibilities were not detected by the DSC method and were observed only when LC analysis was performed. HSM was able to differentiate active pharmaceutical ingredient degradation from solubilisation, supporting the interpretation of DSC in excipients where thermal events either overlapped or disappeared. The combination of both the analytical techniques (DSC and LC) and use of a stability chamber is extremely helpful in detecting incompatibilities and providing more robust and accurate approaches for pre-formulation studies.     

Infrared methods for high throughput screening of metabolites: food and medical applications

Chemical and physiological properties are related to individual or bioactive compounds such as essential oils, terpenoids, flavonoids, volatile compounds and other chemicals which are present in natural products in low concentrations (e.g. ppm or ppb). For many years, classical separation, chromatographic and spectrometric techniques such as high performance liquid chromatography (HPLC), gas chromatography (GC), liquid chromatography (LC) and mass spectrometry (MS) have been used for the elucidation of isolated compounds from different matrices. Hence, the use of standard separation, chromatographic and spectrometric methods was found useful in chemical and both plant and animal physiology studies, for fingerprinting and comparing natural and synthetic samples, as well as to identify single active compounds. It has been generally accepted that a single analytical technique will not provide sufficient visualization of the metabolome, hence holistic techniques are needed for comprehensive analysis. In the last 40 years near infrared (NIR) spectroscopy became one of the most attractive and used methods of analyzing agricultural related products and plant materials which provide simultaneous, rapid and non-destructive quantitation of major. This technique has been reported to determine other minor compounds in plant materials such as volatile compounds and elements. The aim of this short review is to describe some recent applications of NIR spectroscopy combined with multivariate data analysis for high throughput screening of metabolites with an emphasis on food and medical applications.     

A rapid ultra‐performance liquid chromatography/tandem mass spectrometric methodology for the in vitro analysis of Pooled and Cocktail cytochrome P450 assays

Drug‐drug interaction evaluations of new pharmaceutical candidates are critical to preventing drug withdrawal and are routinely determined through the use of cytochrome P450 assays. The measurement of the effect of test compounds on the metabolism of known substrates allows for the determination of specific CYP450 isoenzyme inhibition and calculation of IC50 values. A sensitive, high‐throughput ultra‐performance liquid chromatography/tandem mass spectrometric (UPLC/MS/MS) method is presented for the evaluation of CYP450 inhibition. The assay was performed using a cocktail of probe substrates and the results were compared to those obtained with the more time‐consuming methodology utilizing individual substrates. The use of a high‐resolution, sub‐2 µm particle, LC system allowed for a high‐throughput assay of just 1 min. The extra resolution of the UPLC/MS/MS system allowed for the complete resolution of the analytes, with a fast switching MS for comprehensive data collection. The CYP450 inhibition results obtained using the substrate cocktail approach were found to be essentially identical to those obtained using individual substrates. Copyright © 2009 John Wiley & Sons, Ltd.     

高效液相色谱技术在代谢组学研究中的应用

高效液相色谱技术逐渐广泛应用于代谢组学的研究中。迄今为止,该技术已经在不同生理状态的生物体液的代谢指纹谱分析中得到了应用。本文评述了传统高效液相色谱技术、毛细管技术和超高效液相色谱等技术在代谢组学的应用。     

Qualitative and quantitative determination of YiXinShu Tablet using ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high‐resolution accurate mass spectrometry

To clarify and quantify the chemical profile of YiXinShu Tablet rapidly, a feasible and accurate strategy was developed by applying ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high‐resolution accurate mass spectrometry. A total of 105 components were identified, including 25 phenanthraquinones, 11 lactones, 19 lignans, 24 acids, and 26 other compounds. Among them, 26 major compounds were unambiguously detected by comparing with reference standards. And 19 of these compounds in three batches of YiXinShu Tablet were selected for quantitative determination. (Z )‐Ligustilide, salvianic acid A, salvianolic acid A, salvianolic acid B, and rosmarinic acid were abundant in these three batches with contents over 1 mg/g. The established analysis methods were examined to be accurate and feasible. The results show that the ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high‐resolution accurate mass spectrometry method has a powerful qualitative ability and promising quantitative application.     

High throughput liquid chromatography with sub-2 microm particles at high pressure and high temperature

In this study, ultra performance liquid chromatography (UPLC) using pressures up to 1,000 bar and columns packed with sub-2 microm particles has been combined with high temperature mobile phase conditions (up to 90 degrees C). By using high temperature ultra performance liquid chromatography (HT-UPLC), it is possible to drastically decrease the analysis time without loss in efficiency. The stability and chromatographic behavior of sub-2 microm particles were evaluated at high temperature and high pressure. The chromatographic support remained stable after 500 injections (equivalent to 7,500 column volumes) and plate height curves demonstrated the capability of HT-UPLC to obtain fast separations. For example, a separation of nine doping agents was performed in less than 1 min with sub-2 microm particles at 90 degrees C. Furthermore, a shorter column (30 mm length) was used and allowed a separation of eight pharmaceutical compounds in only 40s.     

Hydrostatic countercurrent chromatography and ultra high pressure LC: Two fast complementary separation methods for the preparative isolation and the analysis of the fragrant massoia lactones

Using a one‐step preparative hydrostatic countercurrent chromatography method, the fragrant massoia lactones were purified from the crude massoia bark oil, in less than 3 h. The fractionation was performed with the biphasic solvent system c‐hexane–methanol–water (10:9:1, v/v/v), leading to target compounds with purity over 96%, as determined by GC‐MS and ultra high pressure LC‐MS analyses. Together with C‐10, C‐12 and C‐14 massoia lactones, two other aromatic compounds used in perfumes, benzyl benzoate and benzyl salicylate, were also obtained as pure compounds. In parallel, an easy and efficient ultra high pressure LC method was developed for the ultra‐fast analysis of massoia lactones, as an alternative to long GC‐MS methods.     

Development and validation of stability indicating chromatographic methods for simultaneous determination of citicoline and piracetam

Citicoline and piracetam were subjected separately to different stress conditions as recommended by the international conference on harmonization. In addition, new stability indicating thin layer chromatographic and ultra high performance liquid chromatographic methods have been developed and validated for simultaneous determination of citicoline and piracetam in presence of their degradation products. Separation on the proposed thin layer chromatographic method was carried out using a developing system containing methanol:chloroform:ammonium chloride buffer (9:1:2, v/v/v) on silica gel plates at 230 nm. On the other hand, the mobile phase in the ultra high performance liquid chromatographic method was composed of water (containing 0.1% triethylamine):ethanol (92:8, v/v). The flow rate was 1 mL/min and ultraviolet detection was at 230 nm. Moreover, results of the developed methods were statistically compared to those obtained by the reported high‐performance liquid chromatography method and no significant difference between them was found. The greenness profile of ultra high performance liquid chromatographic method was assessed and compared with those of the previously published high‐performance liquid chromatography methods, it was noticed that the proposed ultra high performance liquid chromatographic method more environmentally friendly and greener than other methods.     

Semi-targeted analysis of metabolites using capillary-flow ion chromatography coupled to high-resolution mass spectrometry

This work describes a novel application of capillary-flow ion chromatography mass spectrometry for metabolomic analysis, and comparison of the technique to octadecyl silica and hydrophilic interaction chromatography (HILIC)-based mass spectrometry. While liquid chromatography/mass spectrometry (LC/MS) is rapidly becoming the standard technique for metabolomic analysis, metabolomic samples are extremely heterogeneous, leading to a requirement for multiple methods of analysis and separation techniques to perform a 'global' metabolomic analysis. While C18 is suitable for hydrophobic metabolites and has been used extensively in pharmaceutical drug metabolism studies, HILIC is, in general, efficient at separating polar metabolites. Phosphorylated species and organic acids are challenging to analyse and effectively quantitate on both systems. There is therefore a requirement for an MS-compatible analytical technique that can separate negatively charged compounds, such as ion-exchange chromatography. Evaluation of capillary flow ion chromatography with electrolytic suppression was performed on a library of metabolite standards and was shown to effectively separate organic acids and sugar di- and tri-phosphates. Limits of detection for these compounds range from 0.01 to 100 pmol on-column. Application of capillary ion chromatography to a comparative analysis of energy metabolism in procyclic forms of the parasitic protozoan Trypanosoma brucei where cells were grown on glucose or proline as a carbon source was demonstrated to be more effective than HILIC for detection of the organic acids that comprise glucose central metabolism and the tricarboxylic acid (TCA) cycle.