Osmotic implant with membrane and membrane retention means

Abstract

An osmotic delivery system for controlled delivery of a beneficial agent includes an implantable capsule containing a beneficial agent and an osmotic engine that swells on contact with water, thereby causing the release of the beneficial agent over time. The osmotic delivery system has a membrane material that allows a controlled amount of fluid to enter from an exterior of the capsule, while preventing the compositions within the capsule from passing out of the capsule. The osmotic delivery system is designed to meet at least the operating pressures of 1000 psi. The membrane material is cast, calendered or extruded followed by machining (i.e., die-cutting, stamping or otherwise cutting to shape) to provide a uniform nonribbed membrane material. The capsule also includes a membrane material-retaining means that is positioned at a fluid uptake end to retain the membrane material within the capsule, even under periods of high pressure.

1 . A delivery system for controlled delivery of a beneficial agent, the system comprising: 
 an implantable capsule having a beneficial agent delivery end and a fluid uptake end, wherein the implantable capsule comprises one or a plurality of inwardly protruding ridges circumferentially arrayed near the fluid uptake end of the implantable capsule to securingly grip an outer surface of a membrane material;    a beneficial agent reservoir positioned within the implantable capsule for delivery of the beneficial agent at a predetermined delivery rate;    the membrane material received in the fluid uptake end of the implantable capsule and providing a fluid permeable barrier between an interior and an exterior of the implantable capsule; and    a frit positioned at the fluid uptake end of the implantable capsule, for preventing the membrane material from being ejected out of the fluid uptake end of the implantable capsule.    
   
   
       2 . A delivery system for controlled delivery of a beneficial agent, the system comprising: 
 an implantable capsule having a beneficial agent delivery end and a fluid uptake end, wherein the implantable capsule comprises one or a plurality of inwardly protruding ridges circumferentially arrayed near the fluid uptake end of the implantable capsule to securingly grip an outer surface of a membrane material;    a beneficial agent reservoir positioned within the implantable capsule for delivery of the beneficial agent at a predetermined delivery rate;    the membrane material received in the fluid uptake end of the implantable capsule and providing a fluid permeable barrier between an interior and an exterior of the implantable capsule; and    a sintered powdered metal structure including porous capillaries positioned at the fluid uptake end of the implantable capsule for preventing the membrane material from being ejected out of the fluid uptake end of the implantable capsule.    
   
   
       3 . The delivery system according to  claim 2 , wherein a diameter of the porous capillaries is between about 0.5 microns and about 10 microns.  
   
   
       4 . An osmotic system for controlled delivery of a beneficial agent comprising: 
 an implantable capsule having a beneficial agent delivery end and a fluid uptake end;    a beneficial agent reservoir positioned adjacent the beneficial agent delivery end for housing the beneficial agent;    a piston positioned between the beneficial agent reservoir and the fluid uptake end;    an osmotic engine positioned between the piston and the fluid uptake end;    a membrane material received in the fluid uptake end and providing a fluid permeable barrier between an interior and an exterior of the capsule;    one or a plurality of inwardly protruding ridges circumferentially arrayed near the fluid uptake end of the capsule to securingly grip an outer surface of the membrane material;    a membrane material-retaining means positioned at the fluid uptake end, the membrane material-retaining means including at least one opening for allowing passage of fluid, the membrane material-retaining means preventing the membrane material from being ejected out of the fluid uptake end of the capsule; and    wherein the osmotic engine is expandable at a controlled rate and when expanded, applies a pushing force against the piston which applies a pushing force against the beneficial agent, such that the beneficial agent is released through the beneficial agent delivery end at a predetermined rate.    
   
   
       5 . The osmotic system of  claim 4  wherein the material-retaining means comprises a perforated disc.  
   
   
       6 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a frit.  
   
   
       7 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a sintered powdered metal structure including porous capillaries.  
   
   
       8 . The osmotic system of  claim 7 , wherein the diameter of the porous capillaries is between about 0.5 and about 10 microns.  
   
   
       9 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a flange.  
   
   
       10 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a flange with a frit.  
   
   
       11 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a flange with a sintered powdered metal structure including porous capillaries.  
   
   
       12 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a flange that is a separate member attached to the capsule.  
   
   
       13 . The osmotic system of  claim 4 , wherein the membrane material-retaining means comprises a flange that is attached to the capsule by welding, press fit, or screw means.  
   
   
       14 . The osmotic system of  claim 4 , wherein the membrane material-retaining means has a flat, rounded, or contoured surface on at least one surface thereof.  
   
   
       15 . The osmotic system of  claim 4 , wherein the membrane material-retaining means includes at least one opening for allowing passage of fluid.  
   
   
       16 . The osmotic system of  claim 4 , wherein the membrane material comprises a generally smooth, cylindrical shape having a diameter between about 0.040 inch and about 0.250 inch.  
   
   
       17 . The osmotic system of  claim 4 , wherein the membrane material comprises a generally smooth, cylindrical shape having a length or thickness between about 0.010 inch and about 0.350 inch.