Pharmaceutical compositions that have excellent storage even though they include an active component that is susceptible to degradation in an acidic environment are disclosed. The stabilized pharmaceutical composition of the invention includes a ring-opened 7-substituted-,35-dihydroxyheptanoic or a ring opened 7-substituted-3,5-dihydroxyheptenoic acid, or a pharmaceutically acceptable salt thereof, as an component and a stabilizing effective amount of at least one amino-group containing polymeric compound or at least one amino-group containing polymeric compound, or combination thereof wherein the stabilized pharmaceutical composition does not contain a stabilizing effective amount of another stabilizer of a combination of other stabilizers. The pharmaceutical composition may optionally include one or more pharmaceutically acceptable excipients such as a filler, a disintegrating agent and one or more lubricants such as magnesium stearate to aid compression where a tablet dosage form is desired.
