The understanding of solid-state interactions is integral to material sciences and drug formulation within pharmaceutical manufacturing. While traditional organic solid-state chemistry focuses on the reactions of a single species (polymorphism), the work described in the seminar explores solid-solid interactions between paired compounds so as to spontaneously cocrystals. The initial study of caffeine-urea co-crystals, was expanded to investigate the generation theophylline-urea, theophylline-malic acid (L), and caffeine-malic acid (L) cocrystals.