Making students eat their greens: information skills for chemistry students

yesEmployers are increasingly requiring a range of “soft” skills from chemistry graduates, including the ability to search for and critically evaluate information. This paper discusses the issues around encouraging chemistry students to engage with information skills and suggests curricular changes which may help to “drip-feed” information skills into degree programmes

Beta-cyclodextrin (CD) inclusion complexes of disconnected synthetic cannabinoid molecules

SERS has proven to be a powerful screening technique for synthetic cannabinoids. Research shows successful capping of silver nanoparticles with thiolated CDfor the detection of polycyclic aromatic hydrocarbons for SERS enhancement. CD is an oligosaccharide composed of seven α-D-glucopyranoside units and is commonly used in pharmaceuticals and drug delivery as its cavity can be used to form inclusion complexes with hydrophobic molecules

Performance evaluation of two Raman instruments for unknown forensic samples

The Misuse of Drugs Act 1971 classifies Class A, B and C drugs as illegal and over 30000 Class A seizures were reported in England and Wales in 2013/14.1 The drug substance is typically formulated with an array of cutting agents, e.g. Benzocaine, Lidocaine and Phenacetin, leading to a complex mixture of organic species. Early attempts to automate identification of such materials were hampered by spectral overlap and interference. However, developments in computational deconvolution of a spectral data has led to the development of systems that potentially identify targeted components in complex mixtures.2 In this work, a Handheld Raman instrument (Thermo-TruNarc), incorporating an implementation of such an algorithms, was tested with an array of seized samples from UK forensic investigation. These ‘street’ samples were unmodified from seizure and presented as powders (43 samples) and oil (1 sample). The spectral output of the Handheld system was compared with spectra from a laboratory micro-Raman instrument obtained from at least three sites in each sample. Spectra from the laboratory system were assigned and the results compared to the identification reported from the portable system. In 39/44 of cases a valid identification was obtained although, of these, 12 required a sample treatment with an ethanol extraction followed by evaporation onto a proprietary SERS substrate (‘Test-Stick’ analysis). A detailed evaluation of spectral features was undertaken for all cases and where assignments were inconclusive after direct sampling these were mainly attributed to sample fluorescence. Hence, the TruNarc system was shown to be reliable and capable of identifying complex street sample and such identification are available to users with the minimum of spectroscopic expertise

Impact of Mixed Solvent on Co-Crystal Solubility, Ternary Phase Diagram, and Crystallization Scale Up

This contribution covers the identification, understanding, and rationale of the interplay between the choice of mixed solvent on the crystallization of the co-crystal system benzoic acid and isonicotinamide (BZ:INA). A critical first step was gauging the impact of solvent choice and composition on the overall crystallization process, across a number of temperature points. This required defining the solubility and phase diagrams of the co-crystal system at specified temperatures, which reflects the cooling by crystallization profile encountered in a batch crystallization step. To this end, identifying and understanding the impact of solvent composition over a selected temperature range on the solubility of co-crystal underpins this contribution

Creation of a ternary complex between a crown ether, 4-aminobenzoic acid and 3,5-dinitrobenzoic acid

YesThe creation of ternary multi-component crystals through the introduction of 18-crown-6 to direct the hydrogen-bonding motifs of the other molecular components was investigated for 3,5-dinitrobenzoic acid (3,5-dnba) with 4-aminobenzoic acid (4-aba). The creation of a binary complex between 18-crown-6 and 4-aba (C12H24O6·2C7H7NO2)2 and a ternary salt between 3,5-dnba, 18-crown-6 and 4-aba (C12H24O6·C7H8NO2+·C7H3N2O6−·C7H4N2O6) were confirmed by single-crystal structure determination. In both structures, the amino molecules bind to the crown ether through N—H...O hydrogen bonds, leaving available only a single O atom site on the crown with restricted geometry to potentially accept a hydrogen bond from 3,5-dnba. While 3,5-dnba and 4-aba form a binary co-crystal containing neutral molecules, the shape-selective nature of 18-crown-6 preferentially binds protonated amino molecules, thereby leading to the formation of the ternary salt, despite the predicted low concentration of the protonated species in the crystallizing solution. Thus, through the choice of crown ether it may be possible to control both location and nature of the available bonding sites for the designed creation of ternary crystals

English and Irish population comparison using STR markers: Insights into genetic disparities and historical influences

Short tandem repeat (STR) markers are commonly used in forensic investigations and kinship testing due to their cost-effectiveness and high discriminatory power. In the United Kingdom, STR allele frequency databases are available for different population groups, including the White group, which includes individuals of both English and Irish ethnicity. However, considering differences in historical migrations and influences between England and Ireland, distinct genetic differences might exist between these populations. This study aimed to generate allele frequency data for English and Irish populations using the VeriFiler Express PCR Amplification Kit, which contains loci utilised in national databases. Buccal swabs were collected from 577 English and 500 Irish volunteers with self-proclaimed English and Irish ethnicity respectively. DNA profiling and statistical analyses were performed to assess allele frequencies and forensic parameters, and to perform population comparisons. The results showed minimal genetic differentiation (Fst = 0.0013) between the English and Irish populations. Comparison with other European populations revealed close genetic relationships between the English population and Scandinavian countries, while the Irish population displayed closer genetic links to Western European countries. These findings support historical influences such as Viking migrations and highlight the need for further research using additional markers to explore the genetic makeup and history of the English and Irish populations. Although a single allele frequency database may be suitable due to the observed genetic similarity, the establishment of separate databases should be considered to ensure maximum population representation

Rational Development of a Carrier-Free Dry Powder Inhalation Formulation for Respiratory Viral Infections via Quality by Design: A Drug-Drug Cocrystal of Favipiravir and Theophylline

Formulating pharmaceutical cocrystals as inhalable dosage forms represents a unique niche in effective management of respiratory infections. Favipiravir, a broad-spectrum antiviral drug with potential pharmacological activity against SARS-CoV-2, exhibits a low aqueous solubility. An ultra-high oral dose is essential, causing low patient compliance. This study reports a Quality- by-Design (QbD)-guided development of a carrier-free inhalable dry powder formulation containing a 1:1 favipiravir–theophylline (FAV-THP) cocrystal via spray drying, which may provide an alternative treatment strategy for individuals with concomitant influenza infections and chronic obstructive pulmonary disease/asthma. The cocrystal formation was confirmed by single crystal Xray diffraction, powder X-ray diffraction, and the construction of a temperature–composition phase diagram. A three-factor, two-level, full factorial design was employed to produce the optimized formulation and study the impact of critical processing parameters on the resulting median mass aerodynamic diameter (MMAD), fine particle fraction (FPF), and crystallinity of the spray-dried FAV-THP cocrystal. In general, a lower solute concentration and feed pump rate resulted in a smaller MMAD with a higher FPF. The optimized formulation (F1) demonstrated an MMAD of 2.93 μm and an FPF of 79.3%, suitable for deep lung delivery with no in vitro cytotoxicity observed in A549 cells

Validation of reduced volume VeriFiler™ Express PCR Amplification Kit for buccal swab samples extracted using Prep-n-Go™ Buffer

The efficiency of reduced volume PCR amplification was studied using the VeriFiler™ Express PCR Amplification Kit. Full (25 μL) and reduced (5 μL) volumes were tested in parallel to identify any differences in template DNA sensitivity and other electropherogram parameters. Both volumes produced full DNA profiles down to 0.08 ng/μL DNA concentration at 26 PCR cycles; however, reduced volume produced higher peak heights due to increased signal intensities. Significant difference (p-value ≤ 0.05) in heterozygote peak height ratios was observed between both volumes, where the reduced volume threshold was lowered to 0.6 to accommodate all data points. However, no significant difference (p-value > 0.05) was identified in the stutter ratios between both volumes. The analytical threshold for reduced volume was also determined to be 150 RFU with the presence of template DNA in PCR amplification. When the optimized reduced volume parameters were tested on DNA extracted from buccal swab samples using Prep-n-Go™ Buffer, good quality DNA profiles were produced. Overall, the reduced volume not only showed better results compared to the full volume, but also enable more samples to be processed with a PCR amplification kit, thus reduced the cost

Micro/nanoscale magnetic robots for biomedical applications

Magnetic small-scale robots are devices of great potential for the biomedical field because of the several benefits of this method of actuation. Recent work on the development of these devices has seen tremendous innovation and refinement toward ​improved performance for potential clinical applications. This review briefly details recent advancements in small-scale robots used for biomedical applications, covering their design, fabrication, applications, and demonstration of ability, and identifies the gap in studies and the difficulties that have persisted in the optimization of the use of these devices. In addition, alternative biomedical applications are also suggested for some of the technologies that show potential for other functions. This study concludes that although the field of small-scale robot research is highly innovative ​there is need for more concerted efforts to improve functionality and reliability of these devices particularly in clinical applications. Finally, further suggestions are made toward ​the achievement of commercialization for these devices

First Comparative Study of the Three Polymorphs of Bis(isonicotinamide) Citric Acid Cocrystals and the Concomitant Salt 4‑Carbamoylpyridinium Citrate Isonicotinamide

This contribution presents a previously unreported example and comparative study of a binary crystalline adduct that exhibits concomitant salt and cocrystal forms. Specifically, three new polymorphs (α, β, γ) of a novel 2:1 cocrystal of bis(isonicotinamide) citric acid are reported, and the route to isolating each polymorph from aqueous solution is presented and the crystal chemistry of the system is characterized. In addition, the metastable 2:1 salt (ionic adduct) isolated as a transient (overlapping) phase under crystallization conditions identical to the polymorphs is also presented. As far as the authors can ascertain, this may be the first reported example of a salt−cocrystal−polymorphic concomitant system. A comparative study of the solid form landscape is presented, wherein mapping reveals the unique structural complexity of this multiple form salt−cocrystal concomitant system. The α and β forms are structurally very similar, where comparisons of packing behavior are shown to only be different outside the glide plane. The γ form is very different in structure, where supramolecular chirality is present. In addition, further characterization of the isolated solid-state forms includes thermal, spectroscopic, and computational analysis, all of which are employed to further verify the solid form landscape of the isonicotinamide−citric acid adduct and were found to have an order of stability of β, α, γ, salt, the salt being the metastable form