Osmotic drug delivery devices with hydrophobic wall materials

Abstract From the Canadian patent

Osmotically driven drug delivery devices with walls of porous hydrophobic materi-, al as the sole diffusion-limiting wall component are disclosed. Despite pores which are, considerably larger than the molecular dimensions of non-volatile species in the interior, of the device, despite pores which by their hydrophobic character do not permit the pas-, sage of liquid water, and despite the absence of a cellulosic semipermeable membrane, the, devices absorb water by osmosis without loss of the non-volatile species and , function in a, manner analogous to osmotic pumps of the prior art. By permitting the use of hydrophob-, ic substances as the wall material the invention permits the …