The thermodynamic properties of sulphathiazole

Changes in the particle size distribution during tableting of sulphathiazole powder

“…The higher yield value of the finer particles can be discussed further as follows. There are mostly rearrangements of the particles at lower pressure and after the yield has occurred most of the applied stress is transferred to the die wall (Carless & Leigh, 1974). It has also been reported by Fell & Newton (1971) and Armstrong & Haines Nutt (1972b) that the rearrangement of the particles was greater for the fine particles.…”

“…The axial, radial stresses and the linear thickness were read fromtheir relative tracings on thechart. The yield stress was estimated from the axial pressure vs radial stress plot (Carless & Leigh, 1974).…”

The crystallization behaviour of sulphathiazole

“…1B. Our dissolution results (Carless & Jordan, 1974) and present crystallization studies at temperatures varying from 25 to 50" suggest that a purely diffusion-controlled process is operating at 45" which accounts for the linearity of this plot.…”

“…Dissolution kinetic studies showed that the introduction of a dye into the crystallized sulphathiazole reduced the activity of the surface significantly, so that the dissolution process was limited by the interfacial reaction throughout the temperature range studied (25-45") (Carless & Jordan, 1974). We believe that the same is true for crystallization of sulphathiazole although much lower concentrations of dye are required due to the sensitivity of the surface reaction involved in crystallization.…”

“…The dissolution rate constants of sulphathiazole under varying conditions of temperature were shown by Carless & Jordan (1974) to be limited by the interfacial reaction occurring at the solid-liquid boundary at temperatures below 37". Above this temperature, the interfacial reaction became infinitely rapid so that dissolution could be assumed to be limited only by the diffusion of the dissolved solid away from the solid surface.…”