Osmotic dispenser
AssigneeAlza Corporation
InventorsMasahiro Nakano, Takeru Higuchi, Anwar Hussain
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Abstract
An osmotic dispenser is described which is capable of releasing to its outside environment concentrations of active agent at an osmotically controlled rate over a prolonged period of time, and the active agent formulation of which is a solid or semisolid at storage temperatures, advantageously room temperature, and is fluid at the temperature of the prospective situs for the osmotic dispenser, typically at body temperature.
Claims12
An osmotic active agent dispenser comprised of a first compartment of relatively impervious material containing an active agent and provided with means for releasing the active agent to the exterior of the dispenser, and a second compartment of controlled permeability to water containing a solution of an osmotically effective solute which exhibits an osmotic pressure gradient against water, the said first and second compartments having a barrier member such that the said first compartment diminishes in volume in response to an increase in volume of the solution in the said second compartment via absorption of water by osmosis therein, and defining a means for establishing a substantially zero order rate of release, as water flows into the dispenser in a tendency towards osmotic equilibrium with its environment, so that the active agent is continuously squeezed thereout at an osmotically controlled rate over a prolonged period of time;
- said active agent formulated in a form which is a chemically stable solid or semisolid at storage temperatures but a readily dispensible melt at the temperatures of the prospective situs for the osmotic dispenser, whereby the stability and uniformity of dosage of the said active agent over the said prolonged period of time are assured.
Dependencies are inferred from the claim text.