Abstract: Emulsion polymerizations are described in which the monomers include an ethylenically unsaturated ammonium phosphate ester monomer. The processes may be conducted with high total solids, to produce a polymer latex having a solids content in the range 20 to 60%, for instance in the range 25 to 50% by weight. Preferably comonomers include lower alkyl and higher alkyl methacrylate selected to give desirable glass transition temperatures and coalescing films, zwitterionic comonomers, polyethoxylated comonomers to confer desired biocompatibility and latex stability as well as good wetting for a film formed of the polymer and may contain crosslinking monomers, reactive monomers, anionic monomers and/or cationic monomers. The latexes are stable, even when the process is carried out in the substantial absence of non-polymerizable emmulsifier. Coatings formed from the latexes containing zwitterionic comonomer have good biocompatibilizing properties.

Abstract: Copolymers of zwitterionic monomer, especially 2-methacryloyloxyethyl-2?-trimethylammoniumethyl phosphate inner salt, and hydrophobic comonomer, especially dodecylmethacrylate, are made in a monomer starved polymerization process in which solutions of monomers are fed to the reaction vessel in which initiator is present over an extended period. The copolymers have improved compositional uniformity and provide better coatings on a range of substrates. The novel copolymers can be distinguished from prior art batch type bulk solution polymerization polymers of the same monomer composition by solubility characteristics especially in alcohol/water mixtures. Particularly preferred coating compositions comprise an alcohol:water mixture containing around 20 to 40% by volume alcohol.

Abstract: Emulsion polymerisations are described in which the monomers include an ethylenically unsaturated ammonium phosphate ester monomer. The processes may be conducted with high total solids, to produce a polymer latex having a solids content in the range 20 to 60%, for instance in the range 25 to 50% by weight. Preferably comonomers include lower alkyl and higher alkyl methacrylate selected to give desirable glass transition temperatures and coalescing films, zwitterionic comonomers, polyethoxylated comonomers to confer desired biocompatibility and latex stability as well as good wetting for a film formed of the polymer and may contain crosslinking monomers, reactive monomers, anionic monomers and/or cationic monomers. The latexes are stable, even when the process is carried out in the substantial absence of non-polymerisable emmulsifier. Coatings formed from the latexes containing zwitterionic comonomer have good biocompatibilising properties.

Abstract: An implant, usually a stent, has a coating of a cross-linked water swellable polymer matrix preferably having a dry thickness of at least 0.1 &mgr;m, and a pharmaceutically active compound, the polymer having pendant cationic and pendant zwitterionic groups. The active is usually an anionic compound such as a nucleic acid. The polymer is peferably formed from 2-methacyloy-loxyethyl-2′-trimethylammoniumethyl phosphate inner salt, trialkylammoniumalkyl(meth)acrylate and a cross-linkable monomer such as &ohgr;-(trialkoxysilyl)alkyl(meth)acrylate, optionally with a termonomer such as a higher alkyl (meth)acrylate. The stent is coated with polymer, cross-linked then contacted with a solution or dispersion of active compound in a solvent which swells the polymer whereby the active is absorbed into the polymer matrix. The stent is delivered by usual means into a body lumen and the actives released over an extended period of time into the wall of the lumen and/or fluid flowing therein.

Abstract: Emulsion polymerizations are described in which the monomers include an ethylenically unsaturated ammonium phosphate ester monomer. The processes may be conducted with high total solids, to produce a polymer latex having a solids content in the range 20 to 60%, for instance in the range 25 to 50% by weight. Preferably comonomers include lower alkyl and higher alkyl methacrylate selected to give desirable glass transition temperatures and coalescing films, zwitterionic comonomers, polyethoxylated comonomers to confer desired biocompatibility and latex stability as well as good wetting for a film formed of the polymer and may contain crosslinking monomers, reactive monomers, anionic monomers and/or cationic monomers. The latexes are stable, even when the process is carried out in the substantial absence of non-polymerisable emmulsifier. Coatings formed from the latexes containing zwitterionic comonomer have good biocompatibilising properties.

Abstract: An implant, usually a stent, has a coating of a cross-linked water swellable polymer matrix preferably having a dry thickness of at least 0.1 &mgr;m, and a pharmaceutically active compound, the polymer having pendant cationic and pendant zwitterionic groups. The active is usually an anionic compound such as a nucleic acid. The polymer is peferably formed from 2-methacyloyloxyethyl-2′-trimethylammoniumethyl phosphate inner salt, trialkylammoniumalkyl(meth)acrylate and a cross-linkable monomer such as &ohgr;(trialkoxysilyl)alkyl(meth)acrylate, optionally with a termonomer such as a higher alkyl(meth)acrylate. The stent is coated with polymer, cross-linked then contacted with a solution or dispersion of active compound in a solvent which swells the polymer wehereby the active is absorbed into the polymer matrix. The stent is delivered by usual means into a body lumen and the active is released over an extended period of time into the wall of the lumen and/or fluid flowing therein.

Abstract: An implant, usually a stent, has a coating of a cross-linked water swellable polymer matrix preferably having a dry thickness of at least 0.1 &mgr;m, and a pharmaceutically active compound, the polymer having pendant cationic and pendant zwitterionic groups. The active is usually an anionic compound such as a nucleic acid. The polymer is peferably formed from 2-methacyloyloxyethyl-2′-trimethylammoniumethyl phosphate inner salt, trialkylammoniumalkyl(meth)acrylate and a cross-linkable monomer such as &ohgr;(trialkoxysilyl)alkyl(meth)acrylate, optionally with a termonomer such as a higher alkyl(meth)acrylate. The stent is coated with polymer, cross-linked then contacted with a solution or dispersion of active compound in a solvent which swells the polymer wehereby the active is absorbed into the polymer matrix. The stent is delivered by usual means into a body lumen and the active is released over an extended period of time into the wall of the lumen and/or fluid flowing therein.

Abstract: Emulsion polymerisations are described in which the monomers include an ethylenically unsaturated ammonium phosphate ester monomer. The processes may be conducted with high total solids, to produce a polymer latex having a solids content in the range 20 to 60%, for instance in the range 25 to 50% by weight. Preferably comonomers include lower alkyl and higher alkyl methacrylate selected to give desirable glass transition temperatures and coalescing films, zwitterionic comonomers, polyethoxylated comonomers to confer desired biocompatibility and latex stability as well as good wetting for a film formed of the polymer and may contain crosslinking monomers, reactive monomers, anionic monomers and/or cationic monomers. The latexes are stable, even when the process is carried out in the substantial absence of non-polymerisable emmulsifier. Coatings formed from the latexes containing zwitterionic comonomer have good biocompatibilising properties.