X pert pro mpd system

(pyridin-3-yl)methyl 4-(2-(4-((pyridin-3-yl)methoxy)phenyl)diazenyl)benzoate (L1) was prepared according to the literature method [55 (link)]. All other chemicals and reagents were obtained from commercial sources and used as received. Infrared (IR) spectra were recorded with a Varian 800 FT-IR spectrometer (Varian, Inc., Palo Alto, USA) (4000–400 cm⁻¹). Powder X-ray diffraction (PXRD) was performed using a PANalytical X’Pert PRO MPD system (PANalytical B.V., Almelo, Holland).) (PW3040/60). Field emission scanning electron micrographs (SEM) were obtained with a JSM 6701F microscope (Japan Electronics Co., Ltd, Tokyo, Japan). Atomic force microscopy (AFM) images were obtained on a dimension edge microscope (Bruker Nano Inc., Santa Barbara, CA, USA) equipped with a tapping mode. Thermal analyses were performed with a Netzsch STA-449F3 thermogravimetric analyzer (Netzsch, Co., Selb, Germany) at a heating rate of 10 °C min⁻¹ and a flow rate of 20 cm³·min⁻¹ (N₂). Simultaneous inductively coupled plasma optical emission spectrometry (ICP-OES) on a PerkinElmer Optima 8000 instrument (PerkinElmer Inc., Waltham, USA) was used for simultaneous determination of the target elements.

Cryogenically ground binary microparticles were characterized using powder X-ray diffraction (PXRD) and DSC to ensure that mechanical sizing of the solid suspensions did not result in transformation of crystalline ribavirin to a metastable solid phase [32 (link)]. An X’Pert Pro MPD system (PANalytical B.V., Almelo, The Netherlands) was used to generate X-rays at a voltage of 45.0 kV and amperage of 40.0 mA. The instrument was equipped with a Cu anode (λ = 1.5406 Å), an auxiliary elliptical mirror, and an X’Celerator^TM detector (PANalytical B.V., Almelo, The Netherlands). Samples were loaded between 2 layers of Kapton^® film (ChemPlex, Palm City, FL, USA) and rotated using the vertical transmission stage. The goniometer was set to allow consistent irradiation over 5–50°2θ in 0.017°2θ steps at 135 s/step.
The melting temperatures (T_m) of ribavirin polymorphs were measured using conventional DSC. Hermetically sealed aluminum sample pans containing 5.0 ± 0.5 mg of ribavirin were heated at either 2 °C/min or 40 °C/min to 200 °C [33 (link)]. Milled ribavirin:poloxamer microparticles were also analyzed using DSC, and the T_m for ribavirin in these samples was compared with those of the known polymorphs. All measurements were performed in triplicate and reported as mean values ± SD.