RESUMO
The methanol solvate of urapidil was prepared and characterized by means of differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, X-ray powder diffraction, intrinsic dissolution rate, and solution calorimetry. The stoichiometry of the urapidil:methanol solvate was found to be 1:1. The crystal and molecular structures were determined from three-dimensional X-ray data. The stability of the solvate under different storage conditions was also determined.
Assuntos
Piperazinas/análise , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Físico-Química , Ligação de Hidrogênio , Metanol , Microscopia Eletrônica de Varredura , Modelos Químicos , Conformação Molecular , Solubilidade , Espectrofotometria Infravermelho , Temperatura , Termogravimetria , Difração de Raios XRESUMO
Three hydrates of urapidil were prepared and characterized by means of differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, X-ray powder diffraction, intrinsic dissolution rates, and solution calorimetry. The stoichiometry of the urapidil hydrates was found to be 1:5, 1:3, and 1:1 (urapidil:water). The crystal and molecular structures of urapidil pentahydrate were determined from three-dimensional X-ray data. The stability of the pentahydrate and monohydrate under different storage conditions was also determined.
Assuntos
Piperazinas/análise , Fenômenos Químicos , Físico-Química , Cristalografia , Análise Diferencial Térmica , Estabilidade de Medicamentos , Microscopia Eletrônica de Varredura , Solubilidade , Espectrofotometria Infravermelho , Estereoisomerismo , Difração de Raios XRESUMO
Polymorphic forms of urapidil were prepared by various techniques. Three polymorphic forms were identified and their solid-state properties were characterized by thermal behaviour, X-ray powder diffraction, IR spectra, intrinsic dissolution rates, solution calorimetry and scanning electron microscopy. Solution calorimetry was used to determine each polymorph in mixtures of Forms I and II, with a reproducibility of +/-3%. The stability of the three polymorphic forms was followed over a period of three months under different conditions and it was concluded that Forms I, II and III of urapidil were enantiotropic.
