What is the role of current mass spectrometry in pharmaceutical analysis?

Evolution of Mass Spectrometers for High m/z Biological Ion Formation, Transmission, Analysis and Detection: A Personal Perspective

Mass spectrometry (MS) has become an essential tool in virtually all academic, pharmaceutical, and biopharmaceutical analytical laboratories. The specialized and bespoke area of MS research and application of high m/z ion (>m/z 6000 and high mass, >150 kDa) formation, transmission, analysis, and detection is a relatively new area of focus for MS that has seen dramatic acceleration in interest over the last two decades. Herein we delve into this exciting aspect of MS, discussing how MS instrumentation has been refined and evolved for native-MS analysis. We cover the early groundbreaking experiments showing high m/z ion formation, transmission, and preservation of protein structure in the gas phase. Additionally, we discuss specific instrument optimizations and modifications that have advanced high m/z ion generation, transmission, analysis, and detection, contributing to the research area known as gas-phase structural biology. Native-MS sample introduction methods, emerging technologies, and future perspectives are also examined. Finally, we share personal opinions, observations, and experiences that are new to the community or previously unpublished.

Advancements in Electrochemical Biosensors for Comprehensive Glycosylation Assessment of Biotherapeutics

Proteins represent a significant portion of the global therapeutics market, surpassing hundreds of billions of dollars annually. Among the various post-translational modifications, glycosylation plays a crucial role in influencing protein structure, stability, and function. This modification is especially important in biotherapeutics, where the precise characterization of glycans is vital for ensuring product efficacy and safety. Although mass spectrometry-based techniques have become essential tools for glycomic analysis due to their high sensitivity and resolution, their complexity and lengthy processing times limit their practical application. In contrast, electrochemical methods provide a rapid, cost-effective, and sensitive alternative for glycosylation assessment, enabling the real-time analysis of glycan structures on biotherapeutic proteins. These electrochemical techniques, often used in conjunction with complementary methods, offer valuable insights into the glycosylation profiles of both isolated glycoproteins and intact cells. This review examines the latest advancements in electrochemical biosensors for glycosylation analysis, highlighting their potential in enhancing the characterization of biotherapeutics and advancing the field of precision medicine.

Illegal and falsified medicines self-administrated in not approved post-cycle therapy after the cessation of anabolic-androgenic steroids - qualitative analysis

Background

The term post-cycle therapy (PCT) often appears in bodybuilding forums in the context of anabolic-androgenic steroids (AAS) cessation. To reduce the negative impact of AAS on the hormonal system, unapproved PCT is used, which consist of medications that help restore hormonal balance. The most used medicinal products are selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), and preparations containing human chorionic gonadotropin (hCG). These substances are prohibited in sports by the World Anti-Doping Agency.

Methods

Between January 2020 and the end of August 2024, 601 samples seized by the police and prosecutor's office from the illegal market, intended for use as performance-enhancing drugs (PEDs), were tested at the Polish Official Medicines Control Laboratory. Samples were analyzed using accredited methods, including liquid chromatography coupled with high-resolution hybrid mass spectrometry and X-ray powder diffraction, to estimate PCT drug prevalence among other PED samples. In total, 411 (68.4%) samples declaring to contain AAS, 63 (10.5%) declaring to contain substances used in PCT, and 127 (21.1%) other PEDs were tested.

Results

Among the PCT drug samples, 33.3%, 25.4%, and 41.3% indicated the presence of SERMs (tamoxifen and clomiphene), AIs (anastrozole, letrozole, and exemestane), and other substances (hCG, cabergoline, and mesterolone), respectively according to the label. However, not all samples were consistent with the declarations. In 65.1% of the samples, the declared active pharmaceutical ingredients (APIs) were present, whereas in 34.9%, they were not. Furthermore, among the samples in which the declared API was found, 58.7% contained only the declared API, while 6.4% included an additional undeclared API. Conversely, among the samples without the declared API, 20.6% contained neither a declared API nor any API, while 14.3% had other undeclared APIs.

Conclusion

We have shown that illicit drugs used in PCT may be substituted, adulterated, or contain no active ingredients. Our results indicate that in view of the high prevalence of illicit AAS use, the self-administration of unapproved PCT using illegal and falsified medicines is dangerous and can be considered a potential threat to consumer health.

Simultaneous quantification of carbaryl, chlorpyrifos, and paraquat in a municipal wastewater treatment plant by SPE-RP-HPLC-PDA-FD method

Three commonly used pesticides, carbaryl, chlorpyrifos, and paraquat, were quantified by using solid-phase extraction (SPE) technique and high-performance liquid chromatography with photodiode-array and fluorescence detectors (HPLC-PDA-FD) in wastewater treatment plant. After solid-phase extraction, separation, and quantification were done using a C18 analytical column, an isocratic mobile phase consisting of acetonitrile/water (70%:30% v/v) at a flow rate of 1 mL/min, and a column oven maintained at 35 °C. Analyte concentrations were detected simultaneously at 230 nm, 254 nm, and 270 nm. PDA detection at 230 nm gave LOD and LOQ values of 0.65 mg/L and 1.98 mg/L, 0.39 mg/L, and 1.17 mg/L, for carbaryl and chlorpyrifos, respectively. Fluorescence emission peaks, λexc (270 nm) and λem (320 nm), were chosen for detection. FD gave LOD and LOQ values of 0.98 mg/L and 2.96 mg/L, 1.57 mg/L, and 4.76 mg/L, for carbaryl and chlorpyrifos, respectively. Calibration curves based on integrated peak area counts gave satisfactory linearity (R2 ≥ 0.9995). Although exhibiting low detector sensitivity for paraquat at 230 nm, this method is deemed best suited for routine analysis in Wastewater Treatment Plants (WWTPs). The developed and validated method using lower-cost dual detectors, PDA-FD, as a substitute for the higher-cost mass spectrometry is suitable for routine quantitative and qualitative analysis of carbaryl, paraquat, and chlorpyrifos in wastewater and environmental samples.

MS-Based Glycome Characterization of Biotherapeutics With N- and O-Glycosylation

With the increasing FDA approvals of glycoprotein-based biotherapeutics including monoclonal antibodies, cytokines, and enzyme treatments, the significance of glycosylation in modulating drug efficacy and safety becomes central. This review highlights the crucial role of mass spectrometry (MS) in elucidating the glycome of biotherapeutics that feature N- and O-glycosylation, directly addressing the challenges posed by glycosylation complexity and heterogeneity. We have detailed the advancements and application of MS technologies including MALDI-TOF MS, LC-MS, and tandem MS in the precise characterization of glycoprotein therapeutics. Emphasizing MS-based strategies for detecting immunogenic glycans and ensuring batch-to-batch consistency, this review highlights targeted approaches for glycoprotein, glycopeptide, and glycan analysis tailored to meet the stringent analytical and regulatory demands of biopharmaceutical development.

Identification and Characterization of Chemical Compounds in Compound Shougong Powder by UHPLC-Q-TOF/MSE Combined With Multiple Data Processing Techniques

Compound Shougong Powder (CSP) is a traditional Chinese medicine (TCM) preparation recognized for its efficacy in reducing swelling and relieving pain. It is primarily used clinically for the treatment of malignant tumors. However, research on the chemical compounds present in CSP remains limited. In this study, we employed ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MSE) combined with multiple data processing techniques to comprehensively characterize the chemical compounds in CSP. This included a multiple-point screening mass defect filtering (MDF), an enhanced method based on conventional MDF and boundary theory that creates a polygonal filtering zone by connecting numerous endpoints (n ≥ 5) to filter target components. Additional techniques utilized were extracted ion chromatogram (EIC), neutral loss filtering (NLF), diagnostic fragment ion filtering (DFIF), and direct identification methods considering retention time, fragmentation behavior, and reference standards. First, UHPLC-Q-TOF/MSE was applied for comprehensive profiling of CSP's chemical compounds. Then, R language combined with MZmine was used for data preprocessing, enabling the construction of an ion information list to extract valid data. Eventually, through these multiple data processing techniques, a total of 116 chemical compounds in CSP were identified, including 34 flavonoids, 38 saponins, seven stilbenes, six anthraquinones, 12 organic acids, 13 terpenoids, and six others. In summary, this study elucidates the chemical composition of CSP, contributing to the discovery of potential active ingredients for CSP. Additionally, the established strategy provided a powerful guide for the chemical characterization of TCM.

Quantitative Analysis of Drugs in a Mimetic Tissue Model Using Nano-DESI on a Triple Quadrupole Mass Spectrometer

Mass spectrometry is a powerful analytical technique used at every stage of the pharmaceutical research process. A specialized branch of this method, mass spectrometry imaging (MSI), has emerged as an important tool for determining the spatial distribution of drugs in biological samples. Despite the importance of MSI, its quantitative capabilities are still limited due to the complexity of biological samples and the lack of separation prior to analysis. This makes the simultaneous quantification and visualization of analytes challenging. Several techniques have been developed to address this challenge and enable quantitative MSI. One such approach is the mimetic tissue model, which involves the incorporation of an analyte of interest into tissue homogenates at several concentrations. A calibration curve that accounts for signal suppression by the complex biological matrix is then created by measuring the signal of the analyte in the series of tissue homogenates. Herein, we use the mimetic tissue model on a triple quadrupole mass spectrometer (QqQ) in multiple reaction monitoring mode to demonstrate the quantitative abilities of nanospray desorption electrospray ionization (nano-DESI) and compare these results with those obtained using atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI). For the tested compounds, our findings indicate that nano-DESI achieves lower standard deviations than AP-MALDI, resulting in superior limits of detection for the studied analytes. Additionally, we discuss the limitations of the mimetic tissue model in the quantification of certain analytes and the challenges involved with the implementation of the model.

Text Mining and Computational Chemistry Reveal Trends in Applications of Laser Desorption/Ionization Techniques to Small Molecules

Continued development of laser desorption/ionization (LDI) since its inception in the 1960s has produced an explosion of soft ionization techniques, where ionization is assisted by the physical or chemical properties of a structure or matrix. While many of these techniques have primarily been used to ionize large biomolecules, including proteins, some have recently seen increasing applications to small molecules such as pharmaceuticals. Small molecules pose particular challenges for LDI techniques, including interference from the matrix or support in the low mass range. To investigate trends in the application of soft LDI techniques to small molecules, we combined text mining and computational chemistry, looking specifically at matrix substances, analyte properties, and the research domain. In addition to making visible the history of LDI techniques, the results may inform the choice of method and suggest new avenues of method development. All software and collected data are freely available on GitHub (https://github.com/ReinV/SCOPE), VOSviewer (https://www.vosviewer.com), and OSF (https://osf.io/zkmua/).

Exploring the versatility of mass spectrometry: Applications across diverse scientific disciplines

Mass spectrometry (MS) has become a pivotal analytical tool across various scientific disciplines due to its ability to provide detailed molecular information with high sensitivity and specificity. MS plays a crucial role in various fields, including drug discovery and development, proteomics, metabolomics, environmental analysis, and clinical diagnostics and Forensic science. In this article we are discussing the application of MS across the diverse scientific disciplines by focusing on some classical examples from each field of application. As the technology continues to evolve, it promises to unlock new possibilities in scientific research and practical applications, cementing its position as an essential tool in modern analytical science.

Advancing drug safety and mitigating health concerns: High-resolution mass spectrometry in the levothyroxine case study

Levothyroxine is a drug with a narrow therapeutic index. Changing the drug formulation composition or switching between pharmaceutical brands can alter the bioavailability, which can result in major health problems. However, the increased adverse drug reactions have not been fully explained scientifically yet and a thorough investigation of the formulations is needed. In this study, we used a non-targeted analytical approach to examine the various levothyroxine formulations in detail and to reveal possible chemical changes. Ultra-high-performance liquid chromatography coupled with a data-independent acquisition high-resolution mass spectrometry (UHPLC-DIA-HRMS) was employed. UHPLC-DIA-HRMS allowed not only the detection of levothyroxine degradation products, but also the presence of non-expected components in the formulations. Among these, we identified compounds resulting from reactions between mannitol and other excipients, such as citric acid, stearate, and palmitate, or from reactions between an excipient and an active pharmaceutical ingredient, such as levothyroxine-lactose adduct. In addition to these compounds, undeclared phospholipids were also found in three formulations. This non-targeted approach is not common in pharmaceutical quality control analysis. Revealing the presence of unexpected compounds in drug formulations proved that the current control mechanisms do not have to cover the full complexity of pharmaceutical formulations necessarily.

Application of advanced high resolution mass spectrometric techniques for the analysis of losartan potassium regarding known and unknown impurities

Recalls of medicinal products can cause supply bottlenecks. This is often due to the findings of unexpected impurities that pose a health risk to patients. A recent example is losartan potassium which was contaminated with azido-impurities. The choice of the analytical method determines which substances can be detected and thus controlled. In this study a combination of an untargeted screening approach for impurities and a targeted evaluation of high-resolution mass spectrometry data was applied to search for impurities not described so far, leaving out a precise quantification. Six losartan potassium samples were studied regarding known and unknown impurities and hence highlight the applicability and capability of the approach. For separation a Zorbax RR StableBond C18 column (3.0 ×100 mm, particle size of 3.5 µm, pore size of 80 Å), a gradient elution and an electrospray ionization in positive and negative mode for mass spectrometric detection was used. An information-dependent acquisition method was applied for the measurement of losartan potassium samples. The untargeted data evaluation using general unknown comparative screening revealed the presence of N-methyl-2-pyrrolidone (NMP) and another impurity from synthesis. The identity of NMP was corroborated by a spiking experiment and the amount was estimated by means of standard addition. A targeted data evaluation by generating extracted ion chromatograms resulted in finding of four additional impurities. Combined approaches like this are needed to detect and respond to changes in the quality of drugs precociously.

Ultra-high-throughput mass spectrometry in drug discovery: fundamentals and recent advances

INTRODUCTION

Ultra-high-throughput mass spectrometry, uHT-MS, is a technology that utilizes ionization and sample delivery technologies optimized to enable sampling from well plates at > 1 sample per second. These technologies do not need a chromatographic separation step and can be utilized in a wide variety of assays to detect a broad range of analytes including small molecules, lipids, and proteins.

AREAS COVERED

This manuscript provides a brief historical review of high-throughput mass spectrometry and the recently developed technologies that have enabled uHT-MS. The report also provides examples and references on how uHT-MS has been used in biochemical and chemical assays, nuisance compound profiling, protein analysis and high throughput experimentation for chemical synthesis.

EXPERT OPINION

The fast analysis time provided by uHT-MS is transforming how biochemical and chemical assays are performed in drug discovery. The potential to associate phenotypic responses produced by 1000's of compound treatments with changes in endogenous metabolite and lipid signals is becoming feasible. With the augmentation of simple, fast, high-throughput sample preparation, the scope of uHT-MS usage will increase. However, it likely will not supplant LC-MS for analyses that require low detection limits from complex matrices or characterization of complex biotherapeutics such as antibody-drug conjugates.

Identifying the Transients and Transformation Products in Hydroxyl Radical-Methimazole Reactions Using DFT and UPLC-Q-TOF MS/MS Approaches

Oxidative reactions of the hydroxyl radical (·OH) with methimazole (MMI), an antithyroid drug, are crucial for understanding its fate in oxidizing environments. By synergistically integrating density functional theory and ultraperformance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF MS/MS) techniques, we elucidated the transients and transformation products (TPs) arising from the ·OH-MMI reactions. We probed two hydrogen-atom abstraction (HA) reactions, three radical adduct formation reactions, and single electron transfer (SET) at the M06-2X/6-311++G(d,p)/SMD(water) level. All proposed reaction channels, except for HA from the methyl group and SET, were found to be barrier-free. SET is the dominant oxidation pathway, accounting for 44% of oxidations, as determined by branching ratio analysis. The selenium analogue, MSeI, exhibited minor reactivity differences compared to MMI, yet its overall patterns resembled those of ·OH-MMI reactions. TPs were generated experimentally by reacting MMI with ·OH produced by UV-photolysis of H2O2. Eight TPs were identified from an approximately 24% degradation of MMI using UPLC-Q-TOF MS/MS analysis, and an additional two TPs were identified from the approximately 52% degraded MMI sample. The exact identities of all of the TPs were established through their corresponding fragmentation patterns. This study elucidates the drug's susceptibility to free radical species under physiologically relevant conditions.