Foreign matter identification from solid dosage forms

Magnesium stearate surface coverage on tablets and drug crystals: Insights from SEM-EDS elemental mapping

Scanning electron microscopy-based energy dispersive X-ray spectroscopy (SEM-EDS) is proposed as a versatile tool for quantifying surface area coverage (SAC) by magnesium stearate (MgSt) on pharmaceutical tablets and particles. Our approach involved fast elemental mapping and subsequent SAC quantitation by image analysis. The study was conducted using a multi-component system, but the particle-level mapping was limited to active pharmaceutical ingredient (API) crystals. For both tablets and API particles, the calculated SAC against MgSt loading afforded a positive linear correlation over the range of MgSt levels examined in this work. On the tablet surface, MgSt was found to be preferentially concentrated at or in the close vicinity of grain boundaries, supporting the idea of compression-driven migration and relocation of MgSt within the tablet. On the particle surface, only discrete aggregates of MgSt were observed, as opposed to the widely accepted phenomenon of the formation of a thin lubricant film around host particles. The selection of proper SEM-EDS operating conditions and the challenges confronted in particle surface mapping are discussed in detail.

A computational study of the main degradation product of antitumor drug imexon

We theoretically study, from the thermodynamic point of view, the possibility of the two degradation pathways of antitumor drug of imexon. According to the theoretical results obtained at DFT level in both gas and aqueous phases, the two degradation pathways of imexon are characterized by negative reaction Gibbs free energies. It has been found that 4-imino-5-methylene-imidazolidin-2-one is the favored degradation product of imexon.

Herein, the focus of this work has been on calculating the geometries, relative energies and electronic properties of all possible prototropic tautomers of 4-imino-5-methylene-imidazolidin-2-one using the DFT and MP2 levels. The bulk water environment has been simulated by continuum model using Solvation Model based on Density (SMD). The UV spectra of two dominant tautomers of 4-imino-5-methylene-imidazolidin-2-one are also predicted using time-dependent density functional theory and the results are compared with the available experimental data. The comparison of the simulated and the experimental absorption spectra has allowed us to accurately characterize the predominant tautomer of the degradation product in aqueous medium.

Mass Spectrometry Imaging in Oncology Drug Discovery

Over the last decade mass spectrometry imaging (MSI) has been integrated in to many areas of drug discovery and development. It can have significant impact in oncology drug discovery as it allows efficacy and safety of compounds to be assessed against the backdrop of the complex tumour microenvironment. We will discuss the roles of MSI in investigating compound and metabolite biodistribution and defining pharmacokinetic -pharmacodynamic relationships, analysis that is applicable to all drug discovery projects. We will then look more specifically at how MSI can be used to understand tumour metabolism and other applications specific to oncology research. This will all be described alongside the challenges of applying MSI to industry research with increased use of metrology for MSI.

Future directions of imaging MS in pharmaceutical R&D

MS imaging has rapidly evolved over the last decade, finding roles in all aspects of pharmaceutical research and development. This article discusses possible methodological and technological future advancements and describes research areas where the technology can expand and continue to prove to be worthwhile tool for drug discovery and development.