Emprove

Micronized salbutamol sulphate (racemic mixture, Fagron GmbH & Co., Glinde, Germany) with a particle size of Dv_0.1 = 0.43 ± 0.01 μm, Dv_0.5 = 1.53 ± 0.07 μm and Dv_0.9 = 3.79 ± 0.26 μm was chosen as a model API. In line with our previous work [1 (link)], Duralac^© H (16% α anomer and 83.5% β anomer, Meggle, Wasserburg am Inn, Germany), α-lactose monohydrate Flowlac^© 90 (β anomer ≤ 3%, Meggle, Wasserburg am Inn, Germany), Respitose^© SV003 (β anomer ≤ 3%, DFE pharma, Goch, Germany) and Lactohale^© 100 (β anomer ≤ 3%, DFE pharma, Goch, Germany), were used as model carriers. Flowlac^® 90 was dry sieved using a vibratory sieve shaker (Retsch AS200, Germany) to obtain its 20–90 μm particle size fraction. Purified water (TKA Wasseraufbereitunssystem GmbH, Niederelbert, Germany) and acetic acid (Emprove, Merck Millipore, Burlighton, MA, USA) were used to dissolve SS.

VPW from the Touriga Nacional Vitis
vinifera variety was randomly collected at Quinta dos Carvalhais
owned by Sogrape Vinhos, S.A, and located at Mangualde, north of Portugal.
The VPW samples were oven dried (Model no. 2000208, J. P. Selecta,
Barcelona, Spain) at 40 °C for 24 h and milled (ZM200, Retsch,
Porto, Portugal). The milled VPW was sieved to particle size lower
than 1 mm and stored in polyethylene bags at room temperature until
use.
Industrial biodiesel (antioxidant free) samples were supplied
by Enerfuel S.A. (Portugal), produced by alkaline transesterification
of recycled vegetable oils and animal fats in the presence of a catalyst
(potassium methoxide) followed by a purification step by distillation³⁴ and stored at room temperature until use. BHT
was purchased from Sigma-Aldrich (≥99%), hexane (certified
AR for analysis, 95% n-hexane approx) and propan-2-ol
(certified AR for analysis) from Fisher-Chemical, and butanol (EMPLURA)
and benzyl alcohol (EMPROVE) from Merck.

HPLC grade acetonitrile (ACN), methanol, ethyl acetate (EtOAc) (Lichrosolv, purity ≥ 99.9), and glacial acetic acid (Emprove, 100%) were purchased from Merck (Darmstadt, Germany). The water used to prepare the solutions was purified in a Milli-Q Plus system (EMD Millipore, Billerica, MA). Magnesium sulfate, sodium chloride, Supelclean™ primary secondary amine (PSA), pure tetracyclines, sulfonamides, quinolones, macrolides, and antibiotics were provided from Sigma Aldrich (St. Louis, Missouri, USA) and the pesticides were provided from Dr. Ehrenstrorfer (Augsburg, Germany).

The NRL receives strains of C. difficile from voluntary French laboratories for characterisation. Most of these strains are linked to cases reported in the HAI-EWRS (clusters or severe forms of CDI). These strains are characterised by multiplex PCR which detects the main virulence factors (tcdA and tcdB genes encoding toxins A and B, respectively and cdtA and cdtB genes encoding the binary toxin) and by capillary gel-based electrophoresis PCR ribotyping, as described elsewhere [23 (link)]. The strains’ susceptibility patterns to antibiotics (metronidazole, vancomycin, erythromycin, tetracycline and moxifloxacin) are determined by the disk diffusion method. Antimicrobial susceptibility testing was performed according to the 2013 French CA-SFM (Comité de l’antibiogramme de la Société Française de Microbiologie) guidelines. Stain dilution (10⁸ CFU/ml) is inoculated on Brucella Agar (Becton Dickinson) supplemented with vitamin K1 (1mg/ml) (Emprove, Merck), hemin (5 mg/L) (Applichem) and defibrinated horse blood (5%). Plates are incubated 48h at 35–37 °C, and diameters are interpreted according to the criteria for anaerobic bacteria given by the CA-SFM. C. difficile ATCC 700057 is used as quality control. The method was the same throughout the 5 years.