Biodegradable low molecular weight triblock poly(lactide-co-glycolide) polyethylene glycol copolymers having reverse thermal gelation properties
First Claim
1. An aqueous biodegradable polymeric drug delivery composition possessing reverse thermal gelation properties comprised of an aqueous phase having uniformly contained therein:
- (a) an effective amount of a drug; and
(b) a biodegradable ABA-type block copolymer of the formula;
space="preserve" listing-type="equation">PLGA-PEG-PLGAwhere PLGA is a hydrophobic poly(lactide-co-glycolide) copolymer that comprises the A-blocks and PEG is a hydrophilic polyethylene glycol polymer that comprises the B-block, said block copolymer having an average molecular weight of between about 3100 and 4500 wherein, in the block copolymer, the PLGA A-blocks comprise about 51 to 83% by weight of said copolymer and the PEG B-block comprises about 17 to 49% by weight of said copolymer.
16 Assignments
0 Petitions
Accused Products
Abstract
A water soluble biodegradable ABA-type block copolymer made up of a major amount of hydrophobic poly(lactide-co-glycolide) copolymer A-blocks and a minor amount of a hydrophilic polyethylene glycol polymer B-block, having an overall average molecular weight of between about 3100 and 4500, possesses reverse thermal gelation properties. Effective concentrations of the block copolymer and a drug may be uniformly contained in an aqueous phase to form a drug delivery composition. At temperatures below the gelation temperature of the copolymer the composition is a liquid and at temperatures at or above the gelation temperature the composition is a gel or semi-solid. The gelation temperature is preferably at or below body temperature of a warm-blooded animal. The composition may be administered to a warm-blooded animal as a liquid by parenteral, ocular, topical, transdermal, vaginal, transurethral, rectal, nasal, oral, or aural delivery means and is a gel at body temperature. The composition may also be administered as a gel. The drug is released at a controlled rate from the gel which biodegrades into non-toxic products. The release rate of the drug may be adjusted by changing various parameters such as hydrophobic/hydrophilic component content, copolymer concentration, molecular weight and polydispersity of the block copolymer. Because the copolymer is amphiphilic it functions to increase the solubility and/or stability of drugs in the composition.
443 Citations
24 Claims
-
1. An aqueous biodegradable polymeric drug delivery composition possessing reverse thermal gelation properties comprised of an aqueous phase having uniformly contained therein:
-
(a) an effective amount of a drug; and (b) a biodegradable ABA-type block copolymer of the formula;
space="preserve" listing-type="equation">PLGA-PEG-PLGAwhere PLGA is a hydrophobic poly(lactide-co-glycolide) copolymer that comprises the A-blocks and PEG is a hydrophilic polyethylene glycol polymer that comprises the B-block, said block copolymer having an average molecular weight of between about 3100 and 4500 wherein, in the block copolymer, the PLGA A-blocks comprise about 51 to 83% by weight of said copolymer and the PEG B-block comprises about 17 to 49% by weight of said copolymer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
- 9. An aqueous polymeric composition according to claim 9 wherein said drug is an anti-cancer or anti-cell proliferation agent.
-
12. A method for the administration of a drug to a warm blooded animal in a controlled release form which comprises:
-
(1) providing an aqueous biodegradable polymeric drug delivery composition possessing reverse thermal gelation properties comprised of an aqueous phase having uniformly contained therein; (a) an effective amount of a drug; and (b) a biodegradable ABA-type block copolymer of the formula;
space="preserve" listing-type="equation">PLGA-PEG-PLGAwhere PLGA is a hydrophobic poly(lactide-co-glycolide) copolymer that comprises the A-blocks and PEG is a hydrophilic polyethylene glycol polymer that comprises the B-block, said block copolymer having an average molecular weight of between about 3100 and 4500. (2) maintaining said composition as a liquid at a temperature below the gelation temperature of said block copolymer; and (3) administering said composition as a liquid to said warm blooded animal with the subsequent formation of a gel as the temperature of said composition is raised by the body temperature of said animal to be above the gelation temperature of said block polymer. - View Dependent Claims (8, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
Specification