Theophylline–gentisic acid (1/1)

In the title 1:1 cocrystal, C(7)H(8)N(4)O(2)·C(7)H(6)O(4), the anti-asthmatic drug theophylline (systematic name: 1,3-dimethyl-7H-purine-2,6-dione) and a non-steroidal anti-inflammatory drug, gentisic acid (systematic name: 2,5-dihydroxy­benzoic acid) crystallize together, forming two-dimensional hydrogen-bonded sheets involving N—H⋯O and O—H⋯N hydrogen bonds. The overall crystal packing features π–π stacking inter­actions [centroid–centroid distance = 3.348 (1) Å]. The cocrystal described herein belongs to the class of pharmaceutical cocrystals involving two active pharmaceutical ingredients which has been relatively unexplored to date.