Drug delivery device for pharmaceutical compositions

A drug delivery device for the in situ preparation of an extended release oral suspension upon activation of the device, the device comprising:

• a) a first chamber comprising a suspension base;
• b) a second chamber comprising a solid composition comprising cores of active ingredient coated with a release controlling agent to form coated cores;
• and
• c) a breakable substantially impermeable polymeric membrane separating first and second chamber
• wherein, the substantially impermeable polymeric membrane is made up of a polymeric material selected from the group consisting of polyethylene (PE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and high barrier grade PE, has a thickness not less than 0.10 mm and a moisture vapor transmission rate less than about 5.0 g/m2/day;
• and
• wherein, the solid composition remains stable when stored in the drug delivery device at 40° C./75% RH for at least three months.