Abstract: A compound of formula I ##STR1## or a pharmaceutically acceptable salt thereof in which R.sub.1 and R.sub.2 are independently H or methyl (for example N,N-dimethyl-1-[1-(4-chlorophenyl)cyclobutyl]-3-methylbutylamine hydrochloride optionally in the form of its monohydrate) is used for improving the glucose tolerance of humans having non-insulin dependent diabetes mellitus.

Abstract: An improved tablet formulation is provided comprising an effective amount of an active therapeutic agent, especially an acidic therapeutic agent such as aspirin, a release-controlling agent, and an erosion-promoting agent in relative amounts to provide a criticality factor of less than 450, and in proportions of release-controlling and erosion-promoting agent, respectively, between 0.8-1.6 and 1.0-7.5 weight percent per tablet. The tablets of this invention exhibit zero order release in vitro and closely approximate zero order absorption in vivo. The aspirin tablets of the invention produce minimal epigastric distress and can be administered twice-a-day to provide the desired therapeutic effect. The preferred release-controlling agent is cellulose acetate phthalate and the preferred erosion-promoting agent is corn starch.