Репозиторий Университета

© 2021 Elsevier B.V. Based on a comprehensive theoretical and experimental approach, a low-defect thin film of stable dimeric phthalocyanine zinc complex (bis-[2-hydroxy-9(10),16(17), 23(24)-tri-tert-butylphthalocyanine]zinc – J-[OHPctZn]2) was prepared. It is shown that the dye forms stable amorphous edge-on monolayers at the air/water interface with an insignificant content of cylindrical 3D aggregates. These floating layers keep their structure when transferred by the Langmuir-Schaefer method onto a solid substrate, demonstrating a tendency towards ordered H-aggregation with preserving their linear molecular properties. Mixed two- and three-photon absorption of femtosecond laser pulses (280 fs) was firstly detected on this sample, as well as the ability of a material to the nonlinear attenuation of the intense irradiation, which is important for optical limiting.

© 2019 Elsevier B.V. A detailed step-by-step procedure for revealing counterfeit and substandard tablets is presented. Non-invasive NIR measurements are used for data collection. The entire complex multi-layer object as the “packaging -coating-core” system requires special treatment at all stages of model development and validation. The influence of each layer is studied. A procedure that covers data collection, construction of the model, as well as special internal and external validation is advocated here. A special set of objects called ‘nearest of kin’ (NoK) collection, which consists of generic medications nearest to the target objects, assists in reliable assessment of the model specificity. The whole procedure summarizes the results obtained for over a thousand different dosage forms of tablets. Two real-world examples of genuine and counterfeit medicines are considered. The first example presents uncoated tablets with high concentration of active ingredient and fairly simple set excipients. Its NoK collection consists of six different manufacturers. The second example presents coated tablets with low concentration of active ingredient and rather complex set of excipients. Its NoK collection is presented by seven different manufacturers.

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. Near-IR spectroscopy is a promising analytical method in pharmacy. It was shown that it can be used as a rapid method for confirming the identity and analyzing the purity of kemantane (5-hydroxyadamantan-2-one) drug substance.

© 2018 Counterfeit medicines of ‘high quality’ are the most difficult to detect as they have the same chemical composition as the genuine ones, but they are produced by underground manufacturers who violate technological regulations. Our approach is to consider a remedy as a whole object, taking into account the complex composition of APIs, excipients and manufacturing conditions. For rapid testing, the Near Infrared (NIR)-based approach is applied. It entails the acquisition of NIR spectra and processing of the collected data using a modern one-class classifier method called data driven soft independent modeling by class analogy (DD-SIMCA). We present an exemplary analysis of the suspected drugs, which have the same designation and a very similar chemical composition to the brand of a widely used medication used to treat allergies. We recognized the counterfeits using a model that had been previously developed and stored in a library for everyday monitoring in drugstores. We also describe the steps taken in development and validation of DD-SIMCA library models. In the case under consideration, the NIR-based analysis reveals 100% of counterfeits, and this result surpasses the results of the routine compedial tests. Additionally, we present a new instrument, VisCam, that is used in visual analysis of the primary and secondary packages. This instrument combines a tenfold web-camera with different light sources. It is shown that VisCam helps to reveal hidden violations in the primary and secondary packages.