Sustained-release drug carrier composition

A medical device comprising:

• a substrate and a biocompatible coating deposited on at least a fraction of said substrate, wherein said biocompatible coating comprises a matrix composition having an ordered alternating multilayer structure, said matrix composition comprising:
• a. a biodegradable polymer in non-covalent association with a first lipid having a polar group, wherein said first lipid comprises a sterol;
• b. a second lipid comprising at least one phosphatidylcholine having hydrocarbon chains of at least 14 carbons;
• c. at least one pharmaceutical active agent;
• wherein the matrix composition is lipid saturated and said ordered alternating multilayer structure comprises said biodegradable polymer and said lipids, wherein each biodegradable polymer layer is separated by a layer of lipids;
• wherein the weight ratio of total lipids to said biodegradable polymer is between 1.5:1 and 9:1 inclusive;
• and wherein the release time of 90% of the active ingredient from the matrix composition is between 1 week and 6 months, wherein at least 50% of said pharmaceutical active agent is released from the composition at zero-order kinetics when said matrix is maintained in an aqueous environment.