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The ICH guideline Q1B for photostability testing gives guidance on the basic testing protocol required to evaluate the light sensitivity and stability of new drugs and products. The choice of the irradiation method, although complying with the guideline demands, may effect test results. High irradiances may shorten testing times, but can lead to enforcement of photodegradation, which was demonstrated for molsidomine tablets. The exposure to an artificial light source (xenon lamp) was compared and correlated to natural daylight. Suitable testing methods for nifedipine and molsidomine tablets were developed. Deviating from the guideline recommendations, the presentation of powder samples should be done in tiny aluminium pans, facilitating the test procedure, minimising the risk of falsified test results due to improper sampling and improving reproducibility. When using glass dishes for the presentation of tablets to photostability testing, they should be lined by e. g. aluminium foil to avoid influences of light reflected from the sample tray.
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Analyst
August 2025
Department of Chemistry, Atatürk University, Erzurum 25240, Türkiye.
Nitroaniline herbicides are widely used to combat broadleaf weeds, yet their high toxicity and persistence raise serious environmental and health concerns. Effective and sensitive detection of these herbicides in complex matrices such as soil is therefore crucial. In this study, a novel pyrene-modified carbon nanodot (4) was developed and used as a fluorescence nanosensor for the sensitive detection of nitroaniline herbicides in soil samples.
View Article and Find Full Text PDFNanoscale Adv
August 2025
Institute for Experimental Molecular Imaging, RWTH Aachen University Hospital Aachen 52074 Germany
Photoacoustic (PA) imaging is a diagnostic tool widely explored in (pre)clinical settings, as it combines the strengths of optical and ultrasound imaging, resulting in high contrast resolution and deep tissue penetration. Although PA imaging can directly visualize some endogenous molecules ( deoxygenated and oxygenated hemoglobin), most of its applications require the administration of external probes, including organic dyes and inorganic nanoparticles. Despite being historically used for antimicrobial and wound healing applications, silver nanoparticles (AgNPs) possess clear merits for PA imaging, including tunable optical properties, high-quality localized surface plasmon (LSP) resonances, strong photothermal conversions, and photostability.
View Article and Find Full Text PDFJ Mater Chem B
August 2025
CQC-IMS, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535, Coimbra, Portugal.
The global rise of multidrug-resistant (MDR) bacteria highlights the urgent need for alternative strategies to prevent their spread, particularly in healthcare environments. Here, we report the synthesis and evaluation of a novel mono-cationic -imidazolyl porphyrin (3) and its integration into biodegradable poly(lactic acid) (PLA) films, resulting in potentially effective, reusable, and broad-spectrum photodynamic antibacterial surfaces. The porphyrin was prepared using a mixed aldehyde condensation followed by microwave-assisted methylation, reducing reaction time to just 1 minute with near-quantitative yield.
View Article and Find Full Text PDFBiosens Bioelectron
December 2025
Key Laboratory of Green Chemistry and Technology (Ministry of Education), College of Chemistry, Sichuan University, Chengdu, 610064, PR China. Electronic address:
Gastric acid dynamics play a pivotal role in diagnosing gastrointestinal disorders, yet conventional pH monitoring methods, including invasive endoscopy and gastric acid aspiration tests, suffer from poor patient compliance, delayed feedback, and inability to assess drug efficacy in real time. To address these limitations, we developed Si-3Py, a near-infrared (NIR) fluorescent organic small-molecule probe with ultra-acidic pH responsiveness (pKa = 2.32) and exceptional photostability.
View Article and Find Full Text PDFBioorg Chem
August 2025
Laboratory of medico-chirurgical research, biomedicine and infectology, Faculty of Medicine and Pharmacy, University Ibn Zohr, Agadir 80060, Morocco.. Electronic address:
The present study targeted the production of potassium chlorophyllin (KChl), a naturally derived semi-synthetic compound from the green microalga Parachlorella kessleri (P. kessleri). The synthesized derivative was characterized for its spectroscopic, photophysicochemical, structural, morphological and biological properties.
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