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X-ray powder diffraction data for loratadine (C22H23ClN202)

Published online by Cambridge University Press:  03 March 2014

Di Wu ,
Shan Shan Li ,
Kai Lin Xu ,
Li Li Zhang ,
Xiao Qing Wu  and
Hui Li
Di Wu
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Shan Shan Li
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Kai Lin Xu
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Li Li Zhang
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Xiao Qing Wu
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
Hui Li*
Affiliation:
College of Chemical Engineering, Sichuan University, Chengdu 610065, China
*
a)Author to whom correspondence should be addressed. Electronic mail: lihuilab@sina.com

Abstract

X-ray powder diffraction data, unit-cell parameters, and space group for loratadine (C22H23ClN2O2) are reported [a = 28.302(18) Å, b = 4.996(3) Å, c = 29.154(19) Å, β = 109.158(2)°, unit-cell volume V = 3894.25 Å3, Z = 8, and space group C2/c]. All measured lines were indexed and are consistent with the C2/c space group. No detectable impurities were observed.

Keywords

X-ray powder diffractionloratadine

Information

Type
New Diffraction Data
Information
Powder Diffraction , Volume 29 , Issue 2 , June 2014 , pp. 193 - 195
Copyright
Copyright © International Centre for Diffraction Data 2014 

I. INTRODUCTION

Loratadine (Figure 1), systematic name ethyl 4-(8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylate, is a second-generation H1 histamine antagonist drug used to treat allergies such as hay fever (allergic rhinitis), urticaria (hives), and other skin allergies (Haria et al., Reference Haria, Fitton and Peters1994). The oral loratadine is well absorbed from the gastrointestinal tract with rapid first-pass hepatic metabolism (Ghosal et al., Reference Ghosal, Gupta, Ramanathan, Yuan, Lu, Su, Alvarez, Zbaida, Chowdhury and Alton2009).

Figure 1.

Structural formula of loratadine.

The single crystallographic data of loratadine [a = 28.299(3) Å, b = 4.993(1) Å, c = 29.137(3) Å, β = 109.189(9)°, unit-cell volume V = 3888.20 Å3, Z = 8, and space group C2/c] was obtained by Kaminski et al. (Reference Kaminski, Carruthers, Wong, Chan, Billah, Tozzi and McPhail1999). To date, the detailed X-ray powder diffraction data for loratadine have not been reported.

II. EXPERIMENTAL

A. Sample preparation

The title compound was purchased from J&K Chemical Co., Ltd., China and characterized by high-performance liquid chromatography (HPLC), UV and IR. It was recrystallized in methanol, then dried, and ground into powder.

B. Diffraction data collection and reduction

The diffraction pattern for the title compound was collected at room temperature using an X'Pert PRO diffractometer (PANalytical Co., Ltd., Netherlands) with an X'celerator detector and CuKα 1 radiation (λ = 1.54 056 Å, generator setting: 40 kV and 40 mA). The diffraction data were collected over the angular range from 5° to 50° 2θ with a step size of 0.01 313° 2θ and a counting time of 30 s/step. Data evaluation was performed using the software package Material Studio 4.2 (Accelrys Co., Ltd. USA).

The powder diffraction pattern was pre-treated by subtracting the background, smoothing, and eliminating the Kα 2 component. Indexing was carried out using peak positions obtained from the powder diffraction profiles by the X-Cell method. Then the best indexing results with 1094 for the value of figure-of-merit were refined using Pawley refinement (Pan et al., Reference Pan, Guo, Duan, Cheng and Li2012). In the indexing step, MC/SA search algorithm in the Powder Solve package (Engel et al., Reference Engel, Wilke, König, Harris and Leusen1999) was used to constantly adjust the conformation, position, and orientation of the trial model in a unit cell of loratadine. The result of Powder Solve (R wp = 6.74%) was refined by Rietveld refinement techniques based on the experimental X-ray powder diffraction pattern. In the Rietveld refinement (Young, Reference Young1993), variables defining the structural model and the powder diffraction profiles were adjusted by least-squares methods for obtaining an optimal fit between the experimental pattern and calculated pattern. After the Rietveld refinement, the final R wp was 8.94%.

III. RESULTS

The experimental powder diffraction pattern is depicted in Figure 2. Indexing results confirmed that loratadine is monoclinic with space group C2/c and unit-cell parameters after Pawley refinement: a = 28.302(18) Å, b = 4.996(3) Å, c = 29.154(19) Å, β = 109.158(2)°, unit-cell volume V = 3894.25 Å3, and Z = 8 (Table I). A comparison of unit-cell parameters from powder data and single-crystal data (Kaminski et al., Reference Kaminski, Carruthers, Wong, Chan, Billah, Tozzi and McPhail1999) displays a significantly consistency, and the deviations of the two methods were between 0.011 and 0.155%. All lines were indexed and are consistent with the C2/c space group.

Figure 2.

X-ray powder diffraction pattern of the loratadine, using CuKα 1 radiation (λ = 1.54 056 Å).

Table I.

Indexed X-ray powder diffraction data of loratadine (C22H23ClN2O2).

Only the peaks with I rel of 1 or greater are reported [a = 28.302(18) Å, b = 4.996(3) Å, c = 29.154(19) Å, β = 109.158(2)°, unit-cell volume V = 3894.25 Å3, Z = 8, and space group C2/c]. All measured lines were indexed and are consistent with the C2/c space group. The d-values were calculated using CuKα 1 radiation (λ = 1.54 056 Å).

References

Engel, G. E., Wilke, S., König, O., Harris, K. D. M., and Leusen, F. J. J. (1999). “Powder solve-a complete package for crystal structure solution from powder diffraction patterns,” J. Appl. Crystallogr. 32, 1169–1179.Google Scholar
Ghosal, A., Gupta, S., Ramanathan, R., Yuan, Y., Lu, X. W., Su, A. D., Alvarez, N., Zbaida, S., Chowdhury, S. K., and Alton, K. B. (2009). “Metabolism of loratadine and further characterization of its in vitro metabolites,” Drug Metab. Lett. 3, 162–170.Google Scholar
Haria, M., Fitton, A., and Peters, D. H. (1994). “Loratadine: a reappraisal of its pharmacological properties and therapeutic use in allergic disorders,” Drugs 48, 617–637.Google Scholar
Kaminski, J. J., Carruthers, N. I., Wong, S. C., Chan, T. M., Billah, M. M., Tozzi, S., and McPhail, A. T. (1999). “Conformational considerations in the design of dual antagonists of platelet-activating factor (PAF) and histamine,” Bioorg. Med. Chem. 7, 1413–1423.Google Scholar
Pan, Q. Q., Guo, P., Duan, J., Cheng, Q., and Li, H. (2012). “Comparative crystal structure determination of griseofulvin: powder X-ray diffraction versus single-crystal X-ray diffraction,” Chin. Sci. Bull. 57, 3867–3871.Google Scholar
Young, R. A. (1993). The Rietveld Method, IUCr Monographies of Crystallography (Wiley, Oxford).Google Scholar
Figure 0

Figure 1. Structural formula of loratadine.

Figure 1

Figure 2. X-ray powder diffraction pattern of the loratadine, using CuKα1 radiation (λ = 1.54 056 Å).

Figure 2

Table I. Indexed X-ray powder diffraction data of loratadine (C22H23ClN2O2).