at 4 separate study days , the patients received one of the following preparations in a double-blind random order : saline solution , 200 mg of theophylline in 19.9 mg of ethylenediamine ( te200 ) , 351 mg of theophylline in 35 mg of ethylenediamine ( te351 ) , and 200 mg of theophylline in 300 mg of propxyphylline and 300 mg of diprophylline ( tpd ) .
C0039771
theophylline
C0013360
diprophylline