Sustained release drug dispersion delivery device

The present invention is related to a drug delivery device, that is pH insensitive, for the sustained in situ production and release of a dispersion, in an environment of use, which comprises a) a compressed core prepared from an admixture comprising i) a therapeutically effective amount of a beneficial agent that has a solubility profile that is dependent on the pH level of the environment of use; ii) a water swellable polymer which upon hydration forms gelatinous microscopic particles; and iii) a pH modulator; and b) a water insoluble, water impermeable polymeric coating comprising a polymer and a plasticizer, which surrounds and adheres to the compressed core, said water insoluble, water impermeable polymeric coating having at least one aperture.