Data di Pubblicazione:
1998
Citazione:
Crystal forms of piroxicam pivalate: Preparation and characterization of two polymorphs / F. Giordano, A. Gazzaniga, J.R. Moyano, P. Ventura, M. Zanol, T. Peveri, L. Carima. - In: JOURNAL OF PHARMACEUTICAL SCIENCES. - ISSN 0022-3549. - 87:3(1998), pp. 333-337.
Abstract:
This study investigates the polymorphism of piroxicam ester with pivalic acid. Two crystal modifications were prepared by recrystallization from toluene (form 1) and ethyl acetate (form 2). Data regarding preparation conditions, solid state properties, and physicochemical characterization of two polymorphs by means of FT/IR spectroscopy, X-ray diffractometry on powder, and thermal analysis are reported. Heat of fusion rule and thermodynamic formulas consistently indicate an enantiotropic stability relationship of forms 1 and 2 with a calculated transition point (32 °C) near the ambient temperature. The phase diagrams of each polymorph with piroxicam were also investigated in order to gain information about the thermal behavior of their solid mixtures. Liquidus curves calculated by the Schroder-Van Laar equation from fusion enthalpies and temperatures were found to agree satisfactorily with experimental results obtained by first heating runs with differential scanning calorimetry.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
F. Giordano, A. Gazzaniga, J.R. Moyano, P. Ventura, M. Zanol, T. Peveri, L. Carima
Link alla scheda completa: