Impurity identification and quantification for arginine vasopressin by liquid chromatography/high-resolution mass spectrometry

Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis

Pharmaceutical analysis refers to an area of analytical chemistry that deals with active compounds either by themselves (drug substance) or when formulated with excipients (drug product). In a less simplistic way, it can be defined as a complex science involving various disciplines, e.g., drug development, pharmacokinetics, drug metabolism, tissue distribution studies, and environmental contamination analyses. As such, the pharmaceutical analysis covers drug development to its impact on health and the environment. Moreover, due to the need for safe and effective medications, the pharmaceutical industry is one of the most heavily regulated sectors of the global economy. For this reason, powerful analytical instrumentation and efficient methods are required. In the last decades, mass spectrometry has been increasingly used in pharmaceutical analysis both for research aims and routine quality controls. Among different instrumental setups, ultra-high-resolution mass spectrometry with Fourier transform instruments, i.e., Fourier transform ion cyclotron resonance (FTICR) and Orbitrap, gives access to valuable molecular information for pharmaceutical analysis. In fact, thanks to their high resolving power, mass accuracy, and dynamic range, reliable molecular formula assignments or trace analysis in complex mixtures can be obtained. This review summarizes the principles of the two main types of Fourier transform mass spectrometers, and it highlights applications, developments, and future perspectives in pharmaceutical analysis.

Effect of Adulteration on Quality and Preliminary Risk Assessment of the Decoction Pieces of Farfarae Flos Based on the Determination of Hepatotoxic Pyrrolizidine Alkaloids by UHPLC-MS/MS

BACKGROUND

Farfarae Flos (FF) is a frequently used traditional herbal medicine with outstanding antitussive actions. The adulteration of FF decoction pieces is common.

OBJECTIVE

This study aimed to study the effect of adulteration on the safety and quality of FF decoction pieces.

METHODS

The proportion of impurities was conducted by cone quartering method. A simple and accurate ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was established to simultaneous determinate three pyrrolizidine alkaloids (PAs) as endogenous toxic compounds in FF. The traditional medicinal parts (flower bud), impurities (pedicel and rhizome) and unselected samples were determined respectively. The values of estimated daily intake (EDI) and margin of exposure (MOE) were used for risk assessment.

RESULTS

Twenty batches of samples were collected from different habitats, and the proportion of impurities ranged from 17.51% to 41.27%. Pedicel and rhizome were the main impurities, accounting for more than 87.40% of the total impurities. The content of PAs in impurities was significantly higher. The EDI value range was 5.34 to 16.59 μg/kg bw/day, which was much higher than the standard safety value of 7.00 × 10-3 μg/kg bw/day. The MOE values ranges for life long time and shorter exposure were 14.29 to 44.37 and 371.53 to 1153.63, respectively, indicating that at least 80% of the samples had safety risks. Correlation analysis showed that the proportion of adulterated impurities had significant correlation with the values of EDI and MOE.

CONCLUSIONS

Adulteration of non medicinal parts may significantly increase the risk of medications of FF decoction pieces.

HIGHLIGHTS

This study provides an efficient methodology reference for the control of PAs and a basis for adulteration to affect the safety and quality of FF decoction pieces.

G Protein-Coupled Receptor Kinase 2 as Novel Therapeutic Target in Fibrotic Diseases

G protein-coupled receptor kinase 2 (GRK2), an important subtype of GRKs, specifically phosphorylates agonist-activated G protein-coupled receptors (GPCRs). Besides, current research confirms that it participates in multiple regulation of diverse cells via a non-phosphorylated pathway, including interacting with various non-receptor substrates and binding partners. Fibrosis is a common pathophysiological phenomenon in the repair process of many tissues due to various pathogenic factors such as inflammation, injury, drugs, etc. The characteristics of fibrosis are the activation of fibroblasts leading to myofibroblast proliferation and differentiation, subsequent aggerate excessive deposition of extracellular matrix (ECM). Then, a positive feedback loop is occurred between tissue stiffness caused by ECM and fibroblasts, ultimately resulting in distortion of organ architecture and function. At present, GRK2, which has been described as a multifunctional protein, regulates copious signaling pathways under pathophysiological conditions correlated with fibrotic diseases. Along with GRK2-mediated regulation, there are diverse effects on the growth and apoptosis of different cells, inflammatory response and deposition of ECM, which are essential in organ fibrosis progression. This review is to highlight the relationship between GRK2 and fibrotic diseases based on recent research. It is becoming more convincing that GRK2 could be considered as a potential therapeutic target in many fibrotic diseases.

An Overview of Advances in the Chromatography of Drugs Impurity Profiling

A systematic literature survey published in several journals of pharmaceutical chemistry and of chromatography used to analyze impurities for most of the drugs that have been reviewed. This article covers the period from 2016 to 2020, in which almost of chromatographic techniques have been used for drug impurity analysis. These chromatography techniques are important in the analysis and description of drug impurities. Moreover, some recent developments in forced impurity profiling have been discussed, such as buffer solutions, mobile phase, columns, elution modes, and detectors are highlighted in drugs used for the study. This primarily focuses on thorough updating of different analytical methods which include hyphenated techniques for detecting and quantifying impurity and degradation levels in various pharmaceutical matrices.

Amidation/non-amidation top-down analysis of endogenous neuropeptide Y in brain tissue by nano flow liquid chromatography orbitrap Fourier transform mass spectrometry

Neuropeptide Y (NPY) is a transmitter molecule in nerve system, and it was an over 4-kDa large peptide with the C-terminal end amidation. NPY is biosynthesized through many maturation processes from a large pre-pro-peptide with peptide-cleavages and amidation that is important to study the biosynthesis regulation. Previously, it was reported that cathepsin L participates in the production of NPY and that cathepsin L generates both of amidated and non-amidated NPYs. However, the non-amidated NPY (NPY-COOH) has not been reported in brain tissues until now. In this study, endogenous NPY-COOH in mouse brain tissue was detected and identified by using nano flow liquid chromatography (nanoLC) orbitrap Fourier transform mass spectrometry (FT-MS) after the effective purification and separation of NPY-COOH from NPY-amide and other peptides using two different gel-filtration chromatography. Amidated NPY was eluted earlier than non-amidated NPY-COOH in the C18 reversed phase nanoLC and the silica-based gel-filtration chromatogram with hydrophobic interaction. The amount of endogenous NPY-COOH was about 0.05% of the matured NPY-amide amount in adult mouse brain.