Percussively ignited or electrically ingnited self-contained heating unit and drug-supply unit employing same

Abstract

Heating units, drug supply units and drug delivery articles capable of rapid heating are disclosed. Heating units comprising a substrate and a solid fuel capable of undergoing an exothermic metal oxidation reaction disposed within the substrate are disclosed. These heating units can be actuated by electrical resistance or by percussion. Drug supply units and drug delivery articles wherein a solid fuel is configured to heat a substrate to a temperature sufficient to rapidly thermally vaporize a drug disposed thereon are also disclosed.

What is claimed is:  
     
         1 . An percussively ignitable heating unit comprising 
 a sealed enclosure comprising at least one substrate having an exterior surface and an interior surface;    a solid fuel comprising a metal reducing agent and a metal-containing oxidizing agent disposed within the enclosure;    wherein the solid fuel is configured to heat a portion of the exterior surface of the at least one substrate to a temperature of at least 200° C. within at least 500 milliseconds following ignition of the solid fuel; and    a percussive igniter partially disposed with the enclosure, configured to ignite the solid fuel.    
     
     
         2 . The heat unit of  claim 1 , wherein the percussive igniter comprises an anvil partially coated with initiator composition disposed within a deformable metal tube.  
     
     
         3 . The heating unit of  claim 2 , wherein the deformable metal tube is sealed at one end.  
     
     
         4 . The heating unit of  claim 2 , wherein the metal for the metal tube is selected from brass, aluminum, steel, nickel and chromium.  
     
     
         5 . The heating unit of  claim 2 , wherein the anvil is a metal rod or wire.  
     
     
         6 . The heating unit of  claim 1 , wherein the percussive igniter is actuated by mechanical impact.  
     
     
         7 . The heating unit of  claim 6 , wherein the mechanical impact is provided by a spring loaded impinger.  
     
     
         8 . The heating unit of  claim 1 , wherein the substrate is selected from a metal, an alloy, and a ceramic.  
     
     
         9 . The heating unit of  claim 1 , wherein the enclosure comprises more than one substrate.  
     
     
         10 . The heating unit of  claim 1 , wherein the substrate is a metal foil.  
     
     
         11 . The heating unit of  claim 10 , wherein the metal foil exhibits a thickness ranging from 0.001 inches to 0.010 inches.  
     
     
         12 . The heating unit of  claim 1 , wherein the solid fuel is coated as a thin layer on at least a portion of the interior surface of the substrate.  
     
     
         13 . The heating unit of  claim 12 , wherein the thin layer of solid fuel exhibits a thickness ranging from 0.001 inches to 0.030 inches.  
     
     
         14 . The heating unit of  claim 12 , wherein the thin layer of solid fuel exhibits a thickness ranging from 0.001 inches to 0.005 inches.  
     
     
         15 . The heating unit of  claim 1 , wherein the metal containing oxidizing agent is selected from at least one of the following MoO 3 , KClO 4 , KClO 3 , and Fe 2 O 3 .  
     
     
         16 . The heating unit of  claim 1 , wherein the metal reducing agent is selected form at least one of the following: aluminum, zirconium, iron, and titanium.  
     
     
         17 . The heating unit of  claim 1 , wherein the amount of metal reducing agent ranges from 60% by weight to 90% by weight of the total dry weight of the solid fuel.  
     
     
         18 . The heating unit of  claim 1 , wherein the amount of metal-containing oxidizing agent ranges from 10% by weight to 40% by weight of the total dry weight of the solid fuel.  
     
     
         19 . The heating unit of  claim 1 , wherein the solid fuel comprises at least one additive material.  
     
     
         20 . The heating unit of  claim 19 , wherein the additive material is selected from at least one of the following: nitrocellulose, polyvinylalcohol, diatomaceous earth, glass beads, colloidal silica, and Laponite.  
     
     
         21 . The heating unit of  claim 1 , further comprising at least one impulse absorbing material disposed within the enclosure.  
     
     
         22 . The heating unit of  claim 21 , wherein the impulse absorbing material is selected from a porous material, and a fibrous material.  
     
     
         23 . The heating unit of  claim 21 , wherein the impulse absorbing material has a hole contained therein.  
     
     
         24 . The heating unit of  claim 22 , wherein the hole is positioned to direct upon ignition of the primer materials a plume from the primer material to the solid fuel.  
     
     
         25 . The heating unit of  claim 1 , wherein the sealed enclosure is capable of withstanding an internal pressure of at least 50 psig.  
     
     
         26 . A method of making a sealed percussively ignitable heat package comprising: 
 a. coating with a slurry of solid fuel, comprising a metal reducing agent and a metal-containing oxidizing agent, at least a portion of an interior surface of a substrate of an enclosure;    b. disposing partially within the enclosure a percussion igniter with initiator composition disposed therein and configured to ignite the solid fuel; and    c. sealing the enclosure.    
     
     
         27 . The method of  claim 26 , wherein prior to said coating a mask is positioned on a portion of the interior of the surface of the substrate to prevent deposition of the solid fuel said portion.  
     
     
         28 . The method of  claim 26 , wherein said coating comprises 
 a. depositing a slurry of the solid fuel on the interior surface of the substrate with a coating rod to form a thin layer,    b. drying the coated substrate; and    c. removing the mask.    
     
     
         29 . The method of  claim 28 , wherein the thin layer of solid fuel exhibits a thickness ranging from 0.001 inches to 0.030 inches.  
     
     
         30 . The method of  claim 28 , wherein the thin layer of solid fuel exhibits a thickness ranging from 0.001 inches to 0.005 inches.  
     
     
         31 . The method of  claim 26 , wherein said sealing is by use of adhesive, welding, soldering, fastening or crimping.  
     
     
         32 . The method of  claim 26 , further comprising the step of dispensing an additional amount of initiator composition on the solid fuel itself.  
     
     
         33 . The method of  claim 26 , further comprising the step of disposing a spacer within the enclosure.  
     
     
         34 . The method of  claim 26 , further comprising the step of disposing at least one impulse absorbing material within the enclosure.  
     
     
         35 . The method of  claim 26 , wherein the percussive igniter comprises an anvil partially coated with initiator composition disposed within a deformable metal tube.  
     
     
         36 . The method of  claim 35 , wherein the deformable metal tube is sealed at one end.  
     
     
         37 . The method of  claim 36 , wherein the metal for the metal tube is selected from brass, aluminum, steel, nickel and chromium.  
     
     
         38 . The method of  claim 35 , wherein the anvil is a metal rod or wire.  
     
     
         39 . The method of  claim 26 , wherein the substrate is selected from a metal, an alloy, and a ceramic.  
     
     
         40 . The method of  claim 26 , wherein the enclosure comprises more than one substrate.  
     
     
         41 . The method of  claim 26 , wherein the substrate is a metal foil.  
     
     
         42 . The method of  claim 39 , wherein the metal foil exhibits a thickness ranging from 0.001 inches to 0.010 inches.  
     
     
         43 . The method of  claim 26 , wherein the metal containing oxidizing agent is selected from at least one of the following MoO 3 , KClO 4 , KClO 3 , and Fe 2 O 3 .  
     
     
         44 . The method of  claim 26 , wherein the metal reducing agent is selected from at least one of the following: aluminum, zirconium, iron, and titanium.  
     
     
         45 . The method of  claim 26 , wherein the amount of metal reducing agent ranges from 60% by weight to 90% by weight of the total dry weight of the solid fuel.  
     
     
         46 . The method of  claim 26 , wherein the amount of metal-containing oxidizing agent ranges from 10% by weight to 40% by weight of the total dry weight of the solid fuel.  
     
     
         47 . The method of  claim 26 , wherein the solid fuel comprises at least one additive material.  
     
     
         48 . The method of  claim 47 , wherein the additive material is selected from at least one of the following: nitrocellulose, polyvinylalcohol, diatomaceous earth, glass beads, colloidal silica, and Laponite.