Sustained-release drug carrier composition

A non-liposomal matrix composition consisting of:

• (a) a biocompatible non-biodegradable polymer selected from the group consisting of:
• polyethylene glycol, polyethylene glycol acrylate, polyethylene glycol methacrylate, polymethylmethacrylate, polyethylmethacrylate, polybutylmethacrylate, poly-2-ethylhexylmethacrylate, polylaurylmethacrylate, polyhydroxylethyl methacrylate, poly-methylacrylate, 2-methacryloyloxyethylphosphorylcholine (MPC), polystyrene, derivatized polystyrene, polylysine, poly n-ethyl-4-vinyl-pyridinium bromide, polyvinyl acetate, acyl substituted cellulose acetate and polymethacrylic acid alone or as co-polymeric mixtures thereof;
• (b) a first lipid comprising at least one sterol;
• (c) a second lipid comprising at least one phospholipid having fatty acid moieties having at least 14 carbons;
• and
• (d) at least one pharmaceutically active agent;
• (e) optionally, at least one of:
• (i) an additional phospholipid selected from the group consisting of a phosphatidylserine, a phosphatidylglycerol, and a phosphatidylinositol;
• (ii) a sphingolipid;
• (iii) PEGylated lipid
• (iv) tocopherol;
• (v) physiologically acceptable buffer salts;
• or
• (vi) a targeting moiety;
• (f) optionally, a biodegradable polymer, wherein the biodegradable polymer is optionally in the form of a block-co-polymer with the non-biodegradable polymer;
• wherein the non-biodegradable polymer is not covalently bonded to the first and second lipids, and when the matrix composition is maintained in an aqueous environment said matrix composition provides sustained release of the pharmaceutically active agent.