Hydrate formation and dehydration phenomena are frequently encountered phase transformations during manufacturing and storage of the drug products. It is essential to understand, monitor, and control these transformations to ensure that the quality attributes of the drug product are not affected. In this work, phase transformations of the solid forms of amlodipine besylate (AMB) were studied using Raman and near-infrared (NIR) spectroscopy. AMB exists as anhydrate (AH), monohydrate (MH), dihydrate (DH), and amorphous (AM) form. Solid form quantification models based on multivariate data analysis of the Raman and NIR spectra were developed. The AH, MH, and AM form were transformed to the DH during solubility measurements. The AH to DH transformation also occurred during wet granulation. The transformation kinetics were faster during wet granulation than during the solubility experiments. This was due to the shear forces involved in granulation that can facilitate nucleation and can enhance the overall transformation. The DH form present in the wet granules persisted after drying, and final granules contained a mixture of the AH and DH. The relative importance of the dissolution, nucleation, and growth steps for the transformation was elucidated using optical microscopy experiments. The transformation kinetics were found to be limited by nucleation and growth.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jps.22509 | DOI Listing |
Acta Pharm Sin B
December 2024
State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Accurate receptor/ligand binding free energy calculations can greatly accelerate drug discovery by identifying highly potent ligands. By simulating the change from one compound structure to another, the relative binding free energy (RBFE) change can be calculated based on the theoretically rigorous free energy perturbation (FEP) method. However, existing FEP-RBFE approaches may face convergence challenges due to difficulties in simulating non-physical intermediate states, which can lead to increased computational costs to obtain the converged results.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
April 2025
Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, USA.
Rationale: The complexation with dissolved organic matter (DOM) is a pivotal factor influencing transformations, transport, and bioavailability of mercury (Hg) in aquatic environments. However, identifying these complexes poses a significant challenge because of their low concentrations and the presence of coexisting ions.
Methods: In this study, mercury-dissolved organic matter (Hg-DOM) complexes were isolated through solid-phase extraction (SPE) from Hg-humic acid suspensions, and complexes were putatively identified using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS).
Inorg Chem
January 2025
Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
-site cation ordering in double perovskites is crucially important for their physical properties. In this study, polycrystalline samples of Zr-based double perovskite NaLaZrO were synthesized via high-temperature solid-state reactions, and the influence of the heating temperature and cooling rate on their crystal structures was investigated using synchrotron X-ray diffractometry and optical second harmonic generation. The samples prepared at 1200 °C, followed by slow cooling to room temperature, crystallize in a polar 2 structure, exhibiting partial -site cation ordering, with Na- and La-rich -site layers alternately stacked along the axis.
View Article and Find Full Text PDFSci Rep
January 2025
Computational Fluid Dynamics Laboratory, School of Mechanical Engineering, VIT, Vellore, 632014, India.
Stenosis causes the narrowing of arteries due to plaque buildup, which impedes blood flow and affects flow dynamics. This work numerically analyzes flow fluctuations in stenosed arteries under realistic physiological conditions (resting and exercise) and external body acceleration. The artery is inclined at angle , and blood rheology is modeled using a generalized power-law fluid.
View Article and Find Full Text PDFJMIR Form Res
January 2025
Department of Epidemiology and Biostatistics, School of Population Health, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
Background: Public health programs and policies can positively influence food environments. In 2016, a voluntary National Healthy Food and Drink Policy was released in New Zealand to improve the healthiness of food and drinks for hospital staff and visitors. However, no resources were developed to support policy implementation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!