Reconstitutable compositions of biodegradable block copolymers

A composition having enhanced reconstitution properties comprising:

• 1) one or more biodegradable ABA- or BAB-type tri-block copolymers comprising:
• i) 51 to 83% by weight of a biodegradable, hydrophobic A block comprising a biodegradable polyester or poly(ortho ester), and
• ii) 17 to 49% by weight of a hydrophilic B block comprising a polyethylene glycol(PEG), and wherein the tri-block copolymer having a weight average molecular weight of between about 2000 to 4990 and possessing reverse thermal gelation properties, and
• 2) a reconstitution enhancing and enabling agent comprising a polyethylene glycol(PEG), a PEG derivative, or a mixture of PEG and a PEG derivative, said PEG or PEG derivative having a weight averaged molecular weight of 150 to 1100 Daltons, and
• wherein the biodegradable block copolymeric drug carrier is soluble in an aqueous solution and miscible with the reconstitution enhancing and enabling agent.

A composition having enhanced reconstitution properties comprising:

• 1) a biodegradable ABA-type, BAB- or AB-type block copolymer, comprising:
• i) 50.1 to 65% by weight of a biodegradable, hydrophobic A block comprising a biodegradable polyester or poly(ortho ester), and
• ii) 35 to 49.9% by weight of a hydrophilic B block comprising a polyethylene glycol (PEG), and wherein the block copolymer has a weight average molecular weight of between 2400 to 4999 daltons, with the proviso that said block copolymer, when formed as an aqueous polymer solution, is a free flowing liquid at temperatures of between at least 35 to 42° C., and
• 2) a reconstitution enhancing and enabling agent comprising polyethylene glycol(PEG), a PEG derivative, or a mixture of PEG and a PEG derivative, said PEG or PEG derivative having a weight averaged molecular weight of 150 to 1100 Daltons, and
• wherein the biodegradable block copolymeric drug carrier is soluble in an aqueous solution and miscible with the reconstitution enhancing and enabling agent.

A composition having enhanced reconstitution properties comprising:

• 1) a biodegradable polyester or poly(ortho ester) oligomer having a weight average molecular weight of between 400 and 10,000 daltons;
• and a biodegradable AB-type, ABA-type, or BAB-type block copolymer comprising:
• i) 50.1 to 65% by weight of a biodegradable, hydrophobic A block comprising a biodegradable polyester or poly(ortho ester), and
• ii) ii) 35 to 49.9% by weight of a hydrophilic B block comprising a polyethylene glycol (PEG), and wherein the block copolymer has a weight average molecular weight of between 2400 to 4999 daltons, and
• 2) a reconstitution enhancing and enabling agent comprising polyethylene glycol(PEG), a PEG derivative or a mixture of PEG and a PEG derivative, said PEG or PEG derivative having a weight averaged molecular weight of 150 to 1100 Daltons, and
• wherein the biodegradable block copolymeric drug carrier is soluble in an aqueous solution and miscible with the reconstitution enhancing and enabling agent.

A method of reconstituting a drug delivery composition comprising the steps of:

• A) providing a composition having enhanced reconstitution properties comprising:
• 1) one or more biodegradable polymeric block copolymer drug carriers comprising A-B, A-B-A or B-A-B block copolymers having a total weight average molecular weight of 2000 to 8000 Daltons, wherein the A block is a biodegradable polyester or poly(ortho ester) and the B block is polyethylene glycol(PEG), and the weight percentage of the A block is between 50.1 to 83 and the weight percentage of the B block is between 17% to 49.9%;
• and
• 2) a reconstitution enhancing and enabling agent comprising a polyethylene glycol(PEG), a PEG derivative or a mixtures of PEG and a PEG derivative, said PEG or PEG derivative having a weight averaged molecular weight of 150 to 1100 Daltons;
• wherein the biodegradable block copolymeric drug carrier is soluble in an aqueous solution and miscible with the liquid reconstitution enhancing and enabling agent;
• and
• B) mixing water or an aqueous solution with the composition to form a homogeneous solution or an uniform colloidal system.