The misuse of so called novel psychoactive substances is still a challenging problem worldwide. A special attribute of a lot of these compounds is a chiral centre enabling two possible enantiomers probably related to different pharmacological and toxicological properties. The goal of the present study was to present a simple and isocratic HPLC-UV method for enantioseparation of mainly cathinone and pyrovalerone derivatives as well as selected representatives of amphetamines, ketamines, benzofuries, phenidines, phenidates, morpholines and thiophenes. A Waters Acquity UPC2 ® Trefoil™ CEL1 2.5 µm, 3.0 × 150 mm column served as chiral stationary phase by means of cellulose tris-(3,5-dimethylphenylcarbamate) as chiral selector. Mobile phases consisted either of n-hexane/n-butanol/diethylamine (100:0.3:0.2) or n-hexane/diethylamine (100:0.2). The method was found to be applicable for rapid simultaneous chiral separations of cathinone derivatives, to determine enantiomeric elution orders, to detect positional isomers and to identify real-life samples. Also, a repeatability study was performed successfully. 78 out of 95 compounds were separated in their enantiomers successfully, 51 of them within 6 min. It was shown that all NPS bought from online vendors or seized by police were traded as racemic mixtures.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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This study aimed to design a hybrid oral liposomal delivery system for selenium nanoparticles (Lip-SeNPs) to improve the bioavailability of selenium. Thiolated chitosan, a multifunctional polymer with mucoadhesive properties, was used for surface functionalization of Lip-SeNPs. Selenium nanoparticle (SeNP)-loaded liposomes were manufactured by a single step microfluidics-assisted chemical reduction and assembling process. Subsequently, chitosan-N-acetylcysteine was covalently conjugated to the preformed Lip-SeNPs. The Lip-SeNPs were characterized in terms of composition, morphology, size, zeta potential, lipid organization, loading efficiency and radical scavenging activity. A co-culture system (Caco-2:HT29-MTX) that integrates mucus secreting and enterocyte-like cell types was used as a model of the human intestinal epithelium to determine adsorption, mucus penetration, release and transport properties of Lip-SeNPs in vitro. Thiolated Lip-SeNPs were positively charged with an average size of about 250 nm. Thiolated Lip-SeNPs tightly adhered to the mucus layer without penetrating the enterocytes. This finding was consistent with ex vivo adsorption studies using freshly excised porcine small intestinal tissues. Due to the improved mucoadhesion and retention in a simulated microenvironment of the small intestine, thiolated Lip-SeNPs might be a promising tool for oral selenium delivery.

The ongoing development of more and more new psychoactive substances continues to be a huge problem in 2022 affecting the European and international drug market. Through slight alterations in the structure of illicit drugs, a way to circumvent the law is created, as the created derivatives serve as legal alternatives with similar effects. A common way of structure modification is the induction of a halogen residue. Recently, halogenated derivatives of the well-known designer drug 4-methylaminorex appeared on the market and are available in various online shops. In this study, three novel halogenated 4-methylaminorex derivatives, namely 4′-fluoro-4-methylaminorex, 4′-chloro-4-methylaminorex, and 4′-bromo-4-methylaminorex, were purchased online and characterized using nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-high-resolution mass spectrometry (LC-HRMS), and chiral high-performance liquid chromatography with ultraviolet detection (HPLC-UV). These derivatives possess two stereogenic centers, and analyses revealed that all of them were present as a racemic mixture of the trans diastereomeric form.