Crystalline Forms of CAS 124937-52-6 Intermediates
Publication Date: 2013-Jun-20
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Crystalline intermediates for Pfizer active pharmaceutical ingredient 124937-52-6 were characterized using Powder X-ray Diffraction and Differential Scanning Calorimetry
Title: Crystalline Forms of CAS 124937-52-6 Intermediates
Authors: Christina Pattoni, Nicholas J. Lawson, Dennis J. Stelzer
Abstract: Crystalline intermediates for Pfizer active pharmaceutical ingredient 124937-52-6 were characterized using Powder X-ray Diffraction and Differential Scanning Calorimetry.
Summary: Intermediates of active pharmaceutical ingredients often occur in crystalline form. Crystallinity affords advantages of stability of the intermediate and of purification of the intermediate. Two intermediates of 124937-52-6 active pharmaceutical ingredient were characterized using Powder X-ray Diffraction and Differential Scanning Calorimetry.
Powder X-Ray Diffraction (PXRD)
Powder X-ray diffraction was performed using a Scintag X1 Advanced Diffraction System operating under Scintag DMS/NT™ 1.36b and Microsoft Windows 2000 software. The systems use a copper X-ray source maintained at 45 kV and 40 mA to provide Cu KL3 (Ka1) emission of 1.5406 Å and a solid state peltier cooled detector. Beam aperture was controlled using tube divergence and anti-scatter slits of 2 and 4 mm and detector anti-scatter and receiving slits of 0.5 and 0.3 mm width. Data were collected using a step scan of 0.03°/point with a one second/point counting time over a range of 2 to 40° two-theta. Scintag Round, Top Loading stainless steel Sample Cups were utilized for all analyses. Samples were run using the full cup volume when enough material was provided. Otherwise, 12 mm or 9 mm aluminum tray inserts were used to accommodate small sample volumes. Samples were either run without treatment (as is) or after being hand ground (h.g.) using a mortar and pestle just prior to analysis. Data analysis and graphic output were generated using JADE Materials Data software from Materials Data Incorporated. Peaks were identified using a Quartic filter algorithm with a threshold (ESD) of 3.0, an intensity cutoff of 0.5%, and averaging over seven points.
Differential Scanning Calorimetry (DSC)
DSC was performed using a TA Instruments model 2920 module with a Thermal Analyst 5000 controller. Samples of about 1 to 2 mg were accurately weighed into aluminum pans with lids that were crimped to ensure good thermal contact and provide an hermetic seal. The samples were evaluated using a linear heating ramp of 5 °C/min from ambient to approximately 300°C. The cell was purged with a dry nitrogen flow of 40 sccm. Data were collec...