Drug delivery system

• US 4,904,479 A
• Filed: 01/15/1987
• Issued: 02/27/1990
• Est. Priority Date: 01/17/1986
• Status: Expired due to Term

• Current Assignee: West Pharmaceutical Services Drug Delivery & Clinical Research Centre Ltd (Kirin Holdings Company Limited)
• Original Assignee: Danbiosyst UK Ltd (Kirin Holdings Company Limited)
• Inventors: Illum, Lisbeth
• Primary Examiner(s): Griffin, Ronald W.
• Application Number:
  US07/004,189
• Time in Patent Office: 1,139 Days
• Field of Search: 424/490, 424/491, 424/493, 424/496, 424/497, 424/78
• US Class Current: 424/490
• CPC Class Codes: A61K 9/1271 Non-conventional liposomes, e.g. PEGylated liposomes, liposomes coated with polymers liposome as conjugate A61K47/6911
• CPC Class Codes: A61K 9/5031 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/5146 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, polyamines, polyanhydrides

Abstract

Particles of a drug are directed away from the reticuloendothelial system by the use of surface coating and surface grafting techniques which substantially prevent the take up of the composite particles by the liver.

Claims

1. A drug delivery system comprising an active drug as a suspension of colloidal particles, each particle being coated with a material which provides a hydrophilic coat having a thickness of from 100 Å

to 154 Å and

a steric barrier to particle cell interaction.

2. A drug delivery system as claimed in claim 1 in which the coating material is a polymer which is selected to provide an electrostatic barrier as well as said steric barrier.

3. A drug delivery system as claimed in claim 1 in which the coating material is a polyoxypropylene/polyoxyethylene/ethylenediamine block co-polymer having 9 units of polyoxypropylene and an average weight percentage of 80% polyoxyethylene known as poloxamine 908.

4. A drug delivery system as claimed in claim 1 in which the coating material is a polyoxypropylene/polyoxyethylene/propylene glycol block co-polymer having 4 units of polyoxypropylene and an average weight percentage of 70% polyoxyethylene known as poloxamer 407.

5. A drug delivery system in particulate form which following reconstitution is suitable for injection as a suspension of colloidal particles, said system comprising a plurality of composite particles with each particle comprising an active drug in particulate form coated with a material which provides a hydrophilic coat having a thickness in the range of from 100 Å

to 154 Å and

a steric barrier to particle cell interaction.