This progress report presents recent advances in developing a versatile technique for investigation of collisions of ions with open shell neutral intermediates. Combination of a 22-pole ion trap with a beam of H atoms allows accurate determination of rate coefficients at temperatures between 10 K and 300 K. New experimental results on hydrogen abstraction in collisions of CH + , CH 4 + and CH 5 + ions with H atoms are reported at temperatures between 10 K and 100 K. In the case of CH + and CH 4 + , large rate coefficients of 1.3 × 10-9 cm 3 s-1 and 6.0 × 10-10 cm 3 s-1 have been obtained at 50 K. CH + reacts with D atoms with a total rate coefficient of 2.4 × 10-9 cm 3 s-1 the branching ratio being 50 % for hydrogen abstraction and 50 % for atom exchange. For collisions of CH 5 + with H atoms rate coefficients of 9 × 10-12 , 1.3 × 10-11 , and 2.3 × 10-11 cm 3 s-1 have been determined at trap and nozzle temperatures of 10, 50, and 100 K, respectively. This indicates that this reaction is almost thermoneutral in contrast to thermodynamical data reported in the literature.

No abstract

The present study aimed to develop 3D printed dosage forms, using custom-made filaments loaded with diclofenac sodium (DS). The printed tablets were developed by implementing a quality by design (QbD) approach. Filaments with adequate FDM 3D printing characteristics were produced via hot melt extrusion (HME). Their formulation included DS as active substance, polyvinyl alcohol (PVA) as a polymer, different types of plasticisers (mannitol, erythritol, isomalt, maltodextrin and PEG) and superdisintegrants (crospovidone and croscarmellose sodium). The physicochemical and mechanical properties of the extruded filaments were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile measurements. In addition, cylindrical-shaped and tubular-shaped 3D dosage forms were printed, and their dissolution behaviour was assessed via various drug release kinetic models. DSC and XRD results demonstrated the amorphous dispersion of DS into the polymeric filaments. Moreover, the 3D printed tablets, regardless of their composition, exhibited a DS release of nearly 90% after 45 min at pH 6.8, while their release behaviour was effectively described by the Korsmeyer–Peppas model. Notably, the novel tube design, which was anticipated to increase the drug release rate, proved the opposite based on the in vitro dissolution study results. Additionally, the use of crospovidone increased DS release rate, whereas croscarmellose sodium decreased it.