Oxyphenbutazone - a physical characterisation

For this study the physical properties of oxyphenbutazone raw material were investigated with a view to identifying possible polymorphic and pseudopolymorphic crystal forms. Various polymorphic forms were also prepared by means of recrystallization and were characterized. The phenomenon of polymorphism, as well as the thermodynamic aspects involved, was discussed. The preparation of solvates, kinetics of desolvation and the factors influencing desolvation were reviewed. The analytical methods used for drugs in the solid state were summarized. Special attention was given to th practical problems involved in these methods. The techniques discussed included X-ray crystallography, thermogravimetry, differential scanning calorimetry, thermomicroscopy, infra-red spectroscopy, nuclear magnetic resonance spectroscopy and determination of dissolution rate. A short review of the known physical, chemical and pharmacological properties of oxyphenbutazone was given. The above mentioned analytical methods were used to compare six raw materials available in the Republic of South Africa with a USP standard sample. The purity of the samples was confirmed by means of thin layer and liquid chromatography