Claims
- 1. A method of producing prolonged analgesia, comprising administering to a subject in need of such treatment a liposomal composition comprising an analgesic drug, wherein said composition is prepared by (1) incubating a solution comprising an analgesic drug, at a pH which prevents precipitation of the drug from the solution, with a suspension of liposomes having a greater concentration of ammonium ions inside said liposomes than outside said liposomes, and (ii) removing non-encapsulated drug.
- 2. The method of claim 1, wherein said pH is about 6 or less.
- 3. The method of claim 1, wherein said liposomes are GMV liposomes, prepared by (a) vortexing a lipid film with an aqueous solution of ammonium sulfate, (b) homogenizing the resulting suspension to form a suspension of small unilamellar vesicles (SUV), and (c) repeatedly freeze-thawing said suspension of SUV in liquid nitrogen followed by water.
- 4. The method of claim 3, wherein said freeze-thawing is repeated at least five times.
- 5. The method of claim 1, wherein said preparing of said liposomal composition comprising the analgesic drug further comprises concentrating the liposomal suspension by ultrafiltration or centrifugation.
- 6. The method of claim 1, wherein the molar ratio of encapsulated analgesic drug to lipid in said liposomal analgesic composition is at least 1.0
- 7. The method of claim 6, wherein the molar ratio of encapsulated analgesic drug to lipid in said liposomal analgesic composition is at least 1.5.
- 8. The method of claim 1, further comprising cooling the site of administration of said analgesic composition.
- 9. The method of claim 8, wherein said site is cooled such that the local skin temperature is about 22 C.
- 10. The method of claim 1, wherein said analgesic drug is a weakly basic, amphophilic drug.
- 11. The method of claim 10, wherein said analgesic drug is lidocaine or ropivacaine.
Parent Case Info
[0001] This application claims priority to U.S. provisional application serial no. 60/096,331, filed Aug. 12, 1998, which is hereby incorporated by reference in its entirety.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60096331 |
Aug 1998 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09372260 |
Aug 1999 |
US |
Child |
09711991 |
Nov 2000 |
US |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09711991 |
Nov 2000 |
US |
Child |
10771305 |
Feb 2004 |
US |