title: Structure and properties of domperidone and its succinate salt.
abstract: This paper describes the structure and properties of the drug domperidone and a novel 1:1 domperidone succinate salt. The new salt is characterized by means of thermal, spectroscopic, microscopic and powder diffraction measurements. The crystal structures of the salt and, for the first time, of pure domperidone have been determined by means of single-crystal X-ray diffraction. In both structures, the piperidine ring of domperidone adopts the expected chair conformation, and supramolecular centrosymmetric R2(2)(8) motifs are formed by N-H...O hydrogen bonds between chlorine-substituted oxobenzimidazolyl groups. Further N-H...O hydrogen bonds occur between non-substituted oxobenzimidazolyl groups and the resulting C(4) motifs originates hydrogen-bonded chains, extending along the crystallographic b axis. In the salt, a single N-H...O hydrogen bond forms between the protonated nitrogen of the piperidine ring and the carboxylic O atom of the succinate ion. Two alternative and mutually exclusive positions for the nonsubstituted oxobenzimidazolyl group have also been observed; this disorder makes the hydrogen-bonded chains originating from the bicyclic group polar. The dissolution behaviour of the salt in dosage form is compared with two reference commercial products. The salt shows an increased solubility, a characteristic that could be of great advantage from a pharmaceutical view point.
authors.affiliation: CSGI, Department of Chemistry, Physical Chemistry Section, University of Pavia, Viale Taramelli 16, 27100 Pavia, Italy. giovanna.bruni@unipv.it
authors.forename: Giovanna
authors.initials: G
authors.lastname: Bruni
authors.forename: Mariarosa
authors.initials: M
authors.lastname: Maietta
authors.forename: Federico
authors.initials: F
authors.lastname: Scotti
authors.forename: Lauretta
authors.initials: L
authors.lastname: Maggi
authors.forename: Marcella
authors.initials: M
authors.lastname: Bini
authors.forename: Stefania
authors.initials: S
authors.lastname: Ferrari
authors.forename: Doretta
authors.initials: D
authors.lastname: Capsoni
authors.forename: Massimo
authors.initials: M
authors.lastname: Boiocchi
authors.forename: Vittorio
authors.initials: V
authors.lastname: Berbenni
authors.forename: Chiara
authors.initials: C
authors.lastname: Milanese
authors.forename: Alessandro
authors.initials: A
authors.lastname: Girella
authors.forename: Amedeo
authors.initials: A
authors.lastname: Marini
mesh_terms: D018360:Crystallography, X-Ray; D004294:Domperidone / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D012492:Salts / Q000737:chemistry; D019802:Succinic Acid / Q000737:chemistry*
chemical_list: D012492:Salts; D004294:Domperidone; D019802:Succinic Acid
keywords: Fourier transform IR spectroscopy; X-ray powder diffraction; differential scanning calorimetry; dissolution rate; domperidone; energy-dispersive X-ray spectrometry; solubility