OSMOTIC DISPENSER

• US 3,732,865 A
• Filed: 01/13/1971
• Issued: 05/15/1973
• Est. Priority Date: 01/13/1971
• Status: Expired due to Term

• Current Assignee: Harold M. Leeper, Takeru Higuchi
• Original Assignee: Harold M. Leeper, Takeru Higuchi
• Inventors: Higuchi, Takeru, Leeper, Harold M.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): McGowan, J. C.
• Application Number:
  US05/106,130
• Time in Patent Office: 853 Days
• Field of Search: 128/127-131,172,213,218M,260,272,271,261 222/193,389,386.5,130,105,106,94-97 424/15-21
• US Class Current: 604/892.1
• CPC Class Codes: A61F 6/14 intra-uterine type
• CPC Class Codes: A61K 9/0004 Osmotic delivery systems; Sustained release driven by osmosis, thermal energy or gas

Abstract

An osmotic active agent dispenser is comprised of (1) a first compartment of relatively impervious material containing an active agent and provided with an aperture for releasing said active agent to the exterior of the dispenser; (2) a second compartment of controlled permeability to water containing a solution of an osmotically effective solute which exhibits an osmotic pressure gradient against water; and (3) a movable barrier member separating the first from the second compartment. The barrier member is slidably responsive to an increase in volume in the second compartment via absorption of water therein; whereby as water flows by osmosis into the compartment (2) of the dispenser in a tendency towards osmotic equilibrium with its environment, corresponding pressure is exerted behind the barrier (3) driving it into and diminishing the volume of the compartment (1), in turn continuously ejecting active agent thereout at an osmotically controlled rate over a prolonged period of time. In a specific embodiment, the dispenser is comprised of a plurality of capsule half shells one of which compartmentalizing and being free to move within the device, thereby defining a closure for both the active agent compartment and the solution compartment.

Claims

2. The osmotic dispenser as defined by claim 1, further comprising a rapidly soluble fourth half shell capping the active agent release means of the capsule.

3. The osmotic dispenser as defined by claim 1, wherein the active agent is selected from the group consisting of a drug and a bio-affecting composition.

4. The osmotic dispenser as defined by claim 1, wherein the active agent contained therein is in the form of a semisolid formulation.

5. The osmotic dispenser as dEfined by claim 1, wherein the solution of an osmotically effective solute exhibiting an osmotic pressure gradient against water is a saturated aqueous salt solution.

6. The osmotic dispenser as defined by claim 5 wherein the saturated salt solution contains excess solute in solid form.

7. The osmotic dispenser as defined by claim 1, wherein the said second compartment is comprised of a membrane selected from the group consisting of cellulose acetate, silicone rubber, polyurethane, natural rubber and hydrolyzed ethylene/vinyl acetate copolymer.

8. The osmotic dispenser as defined by claim 7, wherein the membrane is anisotropic.

9. The osmotic dispenser as defined by claim 1, wherein the osmotically effective solute is selected from the group consisting of magnesium sulphate, magnesium chloride, sodium chloride, potassium sulphate, sodium carbonate, sodium sulphite, sodium sulphate, sodium bicarbonate, potassium acid phthalate, calcium bicarbonate, potassium acid phosphate, raffinose, tartaric acid, succinic acid, calcium succinate, calcium lactate and magnesium succinate.