Exploring a solvated dimer of Gefitinib: a quantitative analysis. Issue 8 (19th July 2018)

• Record Type: Journal Article
• Authors: Angira, Deekshi; Shaik, Althaf; Kirubakaran, Sivapriya; Thiruvenkatam, Vijay
• Is Part Of: Acta crystallographica. Volume 74:Issue 8(2018)
• Page Start: 944
• Page End: 950
• Publication Date: 2018-07-19
• Subjects: Gefitinib -- solvated dimer -- crystal structure -- Hirshfeld surface -- CLP‐PIXEL -- drug discovery -- drug development -- tyrosine kinase inhibitor -- solvatomorph -- polymorphism; Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229618009671
• Languages: English
• ISSNs: 2053-2296

Abstract

Abstract : Gefitinib (or Iressa) exists in two polymorphic forms, a stable form I and a metastable form II. A methanol solvated form was synthesized and was investigated theoretically and experimentally. Abstract : Gefitinib or Iressa is an orally administered anilinoquinazoline used in cancer chemotherapy for the treatment of lung and breast cancer. It is reported to exist in two polymorphic forms, a stable form I and a metastable form II. Both of the forms belong to the triclinic P space group. In this work, we report the crystallization of Gefitinib to form a methanol solvate [systematic name: N ‐(3‐chloro‐4‐fluorophenyl)‐7‐methoxy‐6‐[3‐(morpholin‐4‐yl)propoxy]quinazolin‐4‐amine methanol hemisolvate, C22 H24 ClFN4 O3 ·0.5CH3 OH] that was theoretically and experimentally investigated. The unit cell is composed of two independent Gefitinib molecules ( A and B ) that form a stable molecular complex with methanol in the crystal lattice. To understand the crystal lattice stabilization, a combination of techniques, namely X‐ray diffraction, IR spectroscopy, thermogravimetric/differential scanning calorimetry (TG‐DSC), Hirshfeld surface analysis and CLP‐PIXEL methods were used. The analysis of the crystal structure of this dimer revealed a three‐dimensional isostructurality with the already reported form II. The A and B molecules are connected via trifurcated C—H…O and N—H…O hydrogen bonding. In addition, the presence of the methanol molecule stabilizes the crystal structure via C—H…O, N—H…O and C—H…Cl interactions between the two monomers. The IR analysis of the dimer has shown characteristic fingerprint values when compared to the commercial form. The TG‐DSC analysis of the solvated dimer is in good agreement with the patent reporting cocrystals of Gefitinib. Finally, theoretical calculations by the CLP‐PIXEL method and Hirshfeld surface and two‐dimensional (2D) fingerprint plot analysis were carried out in order to quantify the different intermolecular interactions and their energies in the crystal packing.