US4702917A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous bioabsorbable polyesters
Assignee: RTI International
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Filing: 1985-11-18
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Granted: 1987-10-27
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Expires: 2005-11-18
Abstract
Abstract Polylactones blended with a polyether and then shaped are leached with aqueous solution of an organic solvent such as alcohol or acetone to elute selectively the polyether and form interconnected pores within the shaped polylactone. The result is a shaped article suitable for use a reservoir for the controlled release of high molecular weight drugs.
Inventors
- 👤 Anton Schindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:06
CPC Classifications
A; A61; A61J; A61J3/00; A61K; A61K9/00; A61K9/0087; A61K9/0092; A61K9/70; A61K9/7007; Y; Y10; Y10T; Y10T428/00; Y10T428/13
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
100 words
A article suitable for use as a controlled release reservoir for high molecular weight drugs, comprising a porous polymer formed by (a) shaping a polylactone in the presence of a polyether comprised of polyoxypropylene and polyoxyethylene; and (b) selectively eluting said polyether with an aqueous solution of an organic solvent from said shaped polylactone at a temperature of about 40° C. to 55° C. to form interconnected pores therein, the resulting pore volume exceeding the amount of material eluted, the resulting product defining a sealed interior reservoir in communication with said pores, which reservoir is suitable to receive said drugs.
Claim 2
Dependent Claim
100 words
A article suitable for use as a controlled release reservoir for high molecular weight drugs, comprising a porous polymer formed by (a) shaping a polylactone in the presence of a polyether comprised of polyoxypropylene and polyoxyethylene; and (b) selectively eluting said polyether with an aqueous solution of an organic solvent from said shaped polylactone at a temperature of about 40° C. to 55° C. to form interconnected pores therein, the resulting pore volume exceeding the amount of material eluted, the resulting product defining a sealed interior reservoir in communication with said pores, which reservoir is suitable to receive said drugs.
Claim 3
Dependent Claim
13 words
The article of claim 1 wherein said polyether is endcapped with acetyl groups.
Claim 4
Dependent Claim
22 words
The article of claim 1 wherein the endcapped polyether of claim 2 is added to the monomeric lactone prior to the polymerization.
Claim 5
Dependent Claim
28 words
The article of claim 1 wherein, prior to said selective elution step, said polyether is present in an amount of 5-50% based on the weight of said blend.
Claim 6
Dependent Claim
22 words
The article of claim 4 wherein said polyether is present in an amount of 10-30% based on the weight of said blend.
Claim 7
Dependent Claim
10 words
The article of claim 1, wherein said polylactone is polycaprolactone.
Claim 8
Dependent Claim
22 words
The article of claim 1, wherein said polylactone is a copolymer formed from caprolactone and at least one other lactone or bis-lactone.
Claim 9
Dependent Claim
16 words
The article of claim 1, wherein said shaped polylactone is in the form of a tube.
Claim 10
Dependent Claim
17 words
The article of claim 1, wherein said organic solvent is acetone present in an amount of 20-70%.
Claim 11
Dependent Claim
19 words
The article of claim 1, wherein said organic solvent is methanol or ethanol present in an amount of 20-50%.
Claim 12
Independent Claim
86 words
A method of fabricating a porous shaped article suitable for use as a controlled release reservoir for high molecular weight drugs, comprising: (a) shaping a blend of a polylactone and polyether comprised of polyoxypropylene and polyoxyethylene to form a shaped article; and (b) selectively eluting said polyether from said shaped article with an aqueous solution of an organic solvent to form interconnected pores therein, said elution step being conducted under temperature conditions such that the resulting pore volume is greater than the amount of material eluted.
Claim 13
Independent Claim
86 words
A method of fabricating a porous shaped article suitable for use as a controlled release reservoir for high molecular weight drugs, comprising: (a) shaping a blend of a polylactone and polyether comprised of polyoxypropylene and polyoxyethylene to form a shaped article; and (b) selectively eluting said polyether from said shaped article with an aqueous solution of an organic solvent to form interconnected pores therein, said elution step being conducted under temperature conditions such that the resulting pore volume is greater than the amount of material eluted.
Claim 14
Dependent Claim
24 words
The method of claim 11 wherein said polyether is endcapped with acetyl groups and is added to the monomeric lactone prior to the polymerization.
Claim 15
Dependent Claim
28 words
The method of claim 12, wherein prior to said selective elution step, said polyether is present in an amount of 5-50% based on the weight of said blend.
Claim 16
Dependent Claim
22 words
The method of claim 13, wherein said polyether is present in an amount of 10-30% based on the weight of said blend.
Claim 17
Dependent Claim
10 words
The method of claim 12, wherein said polylactone is polycaprolactone.
Claim 18
Dependent Claim
22 words
The method of claim 12, wherein said polylactone is a copolymer formed from caprolactone and at least one other lactone or bis-lactone.
Claim 19
Dependent Claim
16 words
The method of claim 12, wherein said shaped polylactone is in the form of a tube.
Claim 20
Dependent Claim
17 words
The method of claim 12, wherein said organic solvent is acetone present in an amount of 20-70%.
Claim 21
Dependent Claim
19 words
The method of claim 12, wherein said organic solvent is methanol or ethanol present in an amount of 20-50%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-26 | 1991-04-27 | 1991-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-26 | 1995-04-27 | 1995-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-26 | 1999-04-27 | 1999-10-27 | $7700.00 | Window Closed / Lapsed |