title: Determination of hydration kinetics of sulfaguanidine anhydrate in aqueous solution by calorimetry.
abstract: A heat conduction microcalorimeter was used to evaluate the isothermal transition in water from anhydrate to monohydrate at 298 K. Sulfaguanidine (SGN) anhydrate was used as a model compound for the measurement of hydration kinetics in water. It is the well-known that SGN is very slightly soluble in water and capable of existing as the anhydrate or monohydrate form in the solid state. The transition rates of SGN anhydrate to monohydrate in tablets and granules were investigated. The hydration kinetics of tablets with controlled surface areas, obtained by coating the side with paraffin in aqueous solution, followed an apparent zero-order mechanism. On the other hand, the transition mechanism of the granules involved a phase boundary-controlled contracting interface reaction.
authors.affiliation: School of Pharmaceutical Sciences, Toho University, Chiba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshihashi
authors.forename: E
authors.initials: E
authors.lastname: Yonemochi
authors.forename: M
authors.initials: M
authors.lastname: Makita
authors.forename: S
authors.initials: S
authors.lastname: Yamamura
authors.forename: E
authors.initials: E
authors.lastname: Fukuoka
authors.forename: K
authors.initials: K
authors.lastname: Terada
mesh_terms: D002151:Calorimetry; D007700:Kinetics; D010232:Paraffin; D010592:Pharmaceutic Aids; D011208:Powders; D012996:Solutions; D013414:Sulfaguanidine / Q000737:chemistry*; D013607:Tablets; D014961:X-Ray Diffraction
chemical_list: D010592:Pharmaceutic Aids; D011208:Powders; D012996:Solutions; D013607:Tablets; D013414:Sulfaguanidine; D010232:Paraffin