Extrudable tubing and solvent bonded fitting for delivery of medicinal fluids

Abstract

Assembly, and method of fabricating an assembly including an extruded polymeric tube and a prefabricated tubular polymer body (fitment), the method including the steps of: extruding an outer tubular surface of a thermoplastic propylene-based elastomer (PBE) material; treating the outer surface along a selected axial length at one end of the tube with a solvent; inserting the treated one end into a hollow tubular passage of a prefabricated tubular body having an inner passage wall of a polypropylene-based material; and allowing the mated juncture to dry such that the treated outer surface solvent bonds to the inner wall. The tubing is preferably a coextruded tube having an innermost layer of a thermoplastic ethylene-based olefinic material. The mating tubing and fitment overcome the prior art problems of stress cracking, fluid contamination and/or processing difficulties.

What is claimed is: 
     
         1 . A method of coaxially bonding a polymeric tube to a prefabricated tubular body, the prefabricated tubular body defining a hollow central tubular passage having a longitudinal axis bounded by an inner wall of polypropylene based material, the method comprising:
 extruding a mating polymeric tube having an outer tubular wall surface comprising thermoplastic propylene-based elastomer (PBE) material, and a central tubular passage having a longitudinal axis and opposing ends,   treating the outer surface of the mating tube along a selected axial length at one of the end of the tube with a solvent that causes the treated outer surface to adhere to the inner wall of the tubular body on drying,   inserting the treated end of the mating tube coaxially into the central tubular passage of the tubular body such that the outer surface of the treated end mates with the inner wall of the tubular body along the selected axial length to form a mated juncture,   allowing the mated juncture to dry such that the treated outer surface solvent bonds to the inner wall.   
     
     
         2 . The method of  claim 1  wherein the solvent is selected from one or more of cyclohexanone, cyclohexane, hexane, xylene, tetrahydrofuran (THF), ethyl acetate (EA) and methyl ethyl ketone (MEK). 
     
     
         3 . The method of  claim 2  wherein the solvent is selected from one or more of cyclohexane, cyclohexanone, xylene, tetrahydrofuran, and hexane. 
     
     
         4 . The method of  claim 2  wherein the PBE is a copolymer or blend of propylene and an alpha-olefin. 
     
     
         5 . The method of  claim 4  wherein the PBE is a propylene/alpha-olefin copolymer with semi-crystalline isotactic propylene segments. 
     
     
         6 . The method of  claim 2  wherein the PBE is a blend of a first polymer component (FPC) which is a predominately crystalline stereoregular polypropylene, and a second polymer component (SPC) which is a crystallizable copolymer of C2,C4-C20 alpha-olefin and propylene. 
     
     
         7 . The method of  claim 4  wherein the alpha-olefin is ethylene. 
     
     
         8 . The method of  claim 1  wherein the tube has an inner wall comprising a layer of a polyethylene (PE). 
     
     
         9 . The method of  claim 8 , wherein the PE of the inner wall is a low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) or blends thereof. 
     
     
         10 . The method of  claim 1  wherein the step of extruding comprises coextruding an outer tubular layer of the PBE material with at least one innermost tubular layer of a thermoplastic ethylene-based olefinic material. 
     
     
         11 . The method of  claim 10  wherein the coextruded outer layer of the mating tube is the PBE with an ethylene content of at least 9% by weight and the innermost layer of the mating tube is polyethylene. 
     
     
         12 . The method of  claim 1 , wherein the tubular body comprises a prefabricated body of PBE material. 
     
     
         13 . The method of  claim 12 , wherein the PBE material of the tubular body is a homopolymer polypropylene or a copolymer of predominately propylene units and ethylene. 
     
     
         14 . A bonded tubular assembly comprising:
 a prefabricated tubular body defining a hollow central tubular passage having a longitudinal axis bounded by an inner wall of propylene-based material,   an extruded tube having an extruded outer tubular wall surface comprising thermoplastic propylene-based elastomer (PBE) material, the mating tube having a central tubular passage having a longitudinal axis and opposing ends,   wherein one of the ends of the mating tube is coaxially positioned within the central tubular passage of the prefabricated tubular body such that the outer surface of the one end of the mating tube is mated with the inner wall of the tubular body along a selected axial length of the mating tube,   the mated outer surface and inner wall being solvent bonded to each other.   
     
     
         15 . The tubular assembly of  claim 14  wherein the extruded tube is a coextruded tube having an outer tubular layer of the PBE material with at least one innermost tubular layer of a thermoplastic ethylene-based olefinic material. 
     
     
         16 . The tubular assembly of  claim 15  wherein the coextruded outer layer of the mating tube is the PBE material with an ethylene content of at least 9% by weight and the innermost layer of the mating tube is polyethylene. 
     
     
         17 . The tubular assembly of  claim 14  wherein the tube has an inner wall forming the central tubular passage comprising a coextruded layer of polyethylene (PE). 
     
     
         18 . The tubular assembly of  claim 15 , wherein the PE is a low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) or blends thereof. 
     
     
         19 . A method of delivering an aqueous based or non-aqueous based medicinal fluid or combination thereof to a patient comprising inserting a fluid delivery member into the body, the member being fluidly connected to the bonded tubular assembly of  claim 14 , and delivering the medical fluid through the tube to the delivery member. 
     
     
         20 . The method of  claim 14 , wherein the medicinal fluid comprises one or more of:
 the nonaqueous solvents selected from the group consisting of: vegetable oils, ethyl oleate, propylene glycol, and polyethylene glycols with molecular weights of 300 and 400.   
     
     
         21 . The method of  claim 14 , wherein the medicinal fluid comprises one or more of:
 synthetic and semisynthetic preparations as solvent or mixed solvent based fluid preparations for injection to the patient, selected from the group consisting of alcohols, esters, ethers, amides, sulfoxides and pyrrolidones.   
     
     
         22 . The method of  claim 21 , wherein the fluid preparations are selected form the group consisting of ethyl alcohol; benzyl alcohol; phenylethyl alcohol; propylene glycol; butylene glycol; trichloro-t-butyl; polyoxyethylene glycol; ethyl ether; phenoxyethanol; ethyl acetate ethyl oleate; benzyl benzoate; N-methylacetamide; N,N-dimethylacetamide; dimethyl sulfoxide (DMSO), and N-methyl 2-pyrrolidone (NMP).