Quantitation of acotiamide in rat plasma by UHPLC-Q-TOF-MS: method development, validation and application to pharmacokinetics

Review on in vivo profiling of drug metabolites with LC-MS/MS in the past decade

Metabolite profiling is an indispensable part of drug discovery and development, enabling a comprehensive understanding of the drug's metabolic behavior. Liquid chromatography-mass spectrometry facilitates metabolite profiling by reducing sample complexity and providing high sensitivity. This review discusses the in vivo metabolite profiling involving LC-MS/MS and the utilization of QTOF, QQQ mass analyzers with a particular emphasis on a mass filter. Further, a summary of sample extraction procedures in biological matrices such as plasma, urine, feces, serum and hair as in vivo samples are outlined. toward the end, we present 15 case studies in biological matrices and their LC-MS/MS conditions to understand the metabolic disposition.

Pharmacokinetic and metabolic analysis of an Alzheimer's disease therapeutic in rat serum via microfluidic CZE-MS

Sensitive, high-throughput methods for pharmacokinetic (PK) profiling are essential for potential therapeutics during critical stages of clinical trials. The application of a microfluidic capillary zone electrophoresis mass spectrometry (CZE-MS) method for PK profiling allows for rapid, sensitive and in-depth analysis of multiple samples within a short timeframe. Here, a CZE-MS approach for PK analysis was compared with a traditional UHPLC-MS approach when analyzing serum extracts from rats treated with a potential Alzheimer's disease therapeutic, BNC-1. Resulting PK data generated from both methods displayed statistical similarities. Additionally, the separation efficiency attributed to the use of the CZE-MS method provided substantial metabolic regulation data that was not apparent in the UHPLC-MS method. Additionally, the coupling of the CZE-MS method to the data processing software, MZmine2, was used to monitor changes in metabolism and observe putative BNC-1-derived metabolites. The ability to perform fast analyses without sacrificing sensitivity or metabolic information suggests that this CZE-MS method is ideal for metabolomics-inclusive, high-throughput PK profiling.

Sulfur-containing therapeutics in the treatment of Alzheimer's disease

Sulfur is widely existent in natural products and synthetic organic compounds as organosulfur, which are often associated with a multitude of biological activities. OBenzothiazole, in which benzene ring is fused to the 4,5-positions of the thiazolerganosulfur compounds continue to garner increasing amounts of attention in the field of medicinal chemistry, especially in the development of therapeutic agents for Alzheimer's disease (AD). AD is a fatal neurodegenerative disease and the primary cause of age-related dementia posing severe societal and economic burdens. Unfortunately, there is no cure for AD. A lot of research has been conducted on sulfur-containing compounds in the context of AD due to their innate antioxidant potential and some are currently being evaluated in clinical trials. In this review, we have described emerging trends in the field, particularly the concept of multi-targeting and formulation of disease-modifying strategies. SAR, pharmacological targets, in vitro/vivo ADMET, efficacy in AD animal models, and applications in clinical trials of such sulfur compounds have also been discussed. This article provides a comprehensive review of organosulfur-based AD therapeutic agents and provides insights into their future development.

Stability-indicating assay method for acotiamide: Separation, identification and characterization of its hydroxylated and hydrolytic degradation products along with a process-related impurity by ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry

RATIONALE

The presence of impurities and degradation products will affect the pharmacokinetic, pharmacodynamic properties and alter the safety of a drug. Hence, the development of a stability-indicating assay method is an integral part of quality product development and is crucial for the regulatory approval of drug products.

METHODS

Acotiamide was subjected to stress degradation under hydrolytic, oxidative, photo and thermal stress conditions. The resulted degradation products (DPs), as well as a process-related impurity (IMP), were selectively separated from the drug on a Waters Acquity HSS cyano column (100 × 2.1 mm, 1.8 μm) with a mobile phase containing a gradient mixture of 0.1% formic acid and acetonitrile (ACN) at a flow rate of 0.25 mL min^-1 .

RESULTS

The drug was found to degrade under hydrolytic (acidic and basic), oxidative and photolytic stress while it remained stable under neutral hydrolytic and thermal stress conditions. The seven degradation products (DPs) and one process-related impurity (IMP) were observed. All the DPs and process-related IMP were well separated by the developed ultra-high-performance liquid chromatography (UHPLC) method and subsequently characterized by UHPLC/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS). The proposed UHPLC method was validated with respect to specificity, linearity, accuracy, precision and robustness as per ICH guideline, Q2 (R1).

CONCLUSIONS

All the observed DPs were new and formed by hydrolysis of an amide bond, phenyl ring hydroxylation and hydrolysis of the methoxy group of the phenyl ring. The despropyl process-related impurity was observed and well separated from the drug. The proposed UHPLC mass spectrometric method has greater utility in the identification of DPs in much less time with excellent selectivity.