Block copolymer

A process for the manufacture of a cross-linked block copolymer having hard and soft segments, there being cross-linking between the soft segments, the process comprising polymerising the monomeric constituents of each soft segment in solution, said constituents including at least one cross-linking agent, then adding the constituents of the hard segment to each resulting solution and polymerising the resulting mix, followed by cross-linking by removal of any solvent, an initiator being added before adding the constituents of the hard segment,

• wherein the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and ISMN, the composition has a saturation concentration of ISMN that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

A cross-linked block copolymer having hard and soft segments, wherein there is cross-linking between said soft segments, said soft segments comprise monomeric units selected from the group consisting of alkyl acrylates and alkyl niethacrylates, and said hard segment polymer comprises at least one monomer selected from the group consisting of styrene, a□methylstyrene, methyl methacrylate, vinyl pyrrolidone and mixtures thereof, and

• wherein the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and ISMN, the composition has a saturation concentration of ISMN that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

A cross-linked block copolymer having hard and soft segments,

• wherein there is cross-linking between said soft segments, said soft segment portion comprises monomeric units selected from the group consisting of alkyl acrylates and alkyl methacrylates, and diacetone acrylamide is an ingredient of at least one soft segment and
• wherein the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and ISMN, the composition has a saturation concentration of ISMN that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

An acrylic cross-linked block copolymer having hard and soft segments, wherein there is cross-linking between the soft segments, and the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and ketoprofen, the composition has a saturation concentration of ketoprofen that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

An acrylic cross-linked block copolymer having hard and soft segments, wherein there is cross-linking between the soft segments, and the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and indomethacin, the composition has a saturation concentration of indometlhacini that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

The block copolymer of clain 54, wherein the block copolymer is an adhesive when in conjunction with one or more adhesive enhancers.

A process for the manufacture of a cross-linked block copolymer having hard and soft segments, there being cross-linking between the soft segments, the process comprising polymerising the monomeric constituents of each soft segment in solution, said constituents including at least one cross-linking agent, then adding the constituents of the hard segment to each resulting solution and polymerising the resulting mix, followed by cross-linking by removal of any solvent, an initiator being added before adding the constituents of the hard segment,

• wherein the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and ketoprofen, the composition has a saturation concentration of ketoprofen that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.

A process for the manufacture of a cross-linked block copolymer having hard and soft segments, there being cross-linking between the soft segments, the process comprising polymerising the monomeric constituents of each soft segment in solution, said constituents including at least one cross-linking agent, then adding the constituents of the hard segment to each resulting solution and polymerising the resulting mix, followed by cross-linking by removal of any solvent, an initiator being added before adding the constituents of the hard segment,

• wherein the block copolymer has sufficient drug retention properties so that, when in a composition containing an amount of adhesive and indomethacin, the composition has a saturation concentration of indomethacin that is at least 10 percent on a weight to weight basis relative to the amount of adhesive in the composition.