| abstract |
(57) The instant invention is directed to an osmotic pump comprising:n (a) at least one active agent surrounded by (b) a water insoluble wall, having a fluid permeability of 6.96 x 10 -18 to 6.96 x 10 -14 cm 3 sec/g and a reflection coefficient of less than 1, prepared from: (i) a polymer permeable to water but impermeable to solute, and (ii) 0.1 to 60% by weight, based on the total weight of (i) and (ii), of at least one pH insensitive pore forming additive dispersed throughout said wall. |