Crystal structure of loteprednol etabonate Form II, C24H31ClO7. Issue 1 (March 2021)

• Record Type: Journal Article
• Authors: Kaduk, James A.; Gindhart, Amy M.; Blanton, Thomas N.
• Is Part Of: Powder diffraction. Volume 36:Issue 1(2021)
• Page Start: 50
• Page End: 55
• Publication Date: 2021-03
• Subjects: loteprednol etabonate, -- Alrex, -- powder diffraction, -- Rietveld refinement, -- density functional theory; Powder metallurgy -- Periodicals; Materials -- Analysis -- Periodicals; 620.1127
• DOI: 10.1017/S0885715621000038
• Languages: English
• ISSNs: 0885-7156

Abstract

Abstract : The crystal structure of loteprednol etabonate Form II has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Loteprednol etabonate Form II crystallizes in the space group P21 (#4) with a = 11.96312(6), b = 14.91862(5), c = 6.75715(3) Å, β = 94.1584(3)°, V = 1202.796(6) Å 3, and Z = 2. The crystal structure is characterized by herringbone layers in the ab -plane. The anisotropic displacement ellipsoid of the Cl atom is not oriented in a way which corresponds to a chemically sensible motion of this atom. The sample suffered damage in the X-ray beam, probably involving photolysis of the C–Cl bond. The most prominent hydrogen bond is the O–H⋯O hydrogen bond between the hydroxyl group and the carbonyl group of the steroid A ring. This hydrogen bond links the molecules into C 1, 1(9) chains along the b -axis. The powder pattern is included in the Powder Diffraction File™ (PDF®) as entry 00-066-1602; this study will allow inclusion of the atomic coordinates to the PDF entry.