title: Spectrophotometric determination of theophylline, dyphylline and khellin in some pharmaceutical preparations.
mesh_terms: D007666:Khellin / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013806:Theophylline / Q000031:analogs & derivatives* / Q000032:analysis*
chemical_list: D007666:Khellin; D013806:Theophylline