The book presents an overview of the solid-state kinetic literature including methodologies used, mathematical derivations and pharmaceutical applications. The book investigates the relationship between calculation methods and artifactual results observed in solid-state kinetics. A new approach is proposed for evaluating solid-state kinetic data, this approach combines modelistic and model-free methods in a complimentary manner to achieve consistent kinetic results. Experimental data focused on studying the solid-state stability of several structurally related solvates of sulfameter (5-methoxysulfadiazine), this was done by studying the kinetics of their desolvation reaction both isothermally and nonisothermally. Calculated kinetic parameters were compared and related to the crystal structure of these solvates. A relationship was established between desolvation kinetic parameters (e.g., activation energy) and the solvent size. The solid-state reaction models selected also corresponded to the single crystal structure of the sulfameter-solvate system.