Claims for Patent: 5,931,809

Summary for Patent: 5,931,809

Title:	Epidural administration of therapeutic compounds with sustained rate of release
Abstract:	A drug delivery system provides sustained-release delivery of therapeutic biologically active compounds administered epidurally. In the preferred embodiment the biologically active compound is an opioid, which is encapsulated within the non-concentric internal aqueous chambers or bilayers of multivesicular liposomes. The opioid is released over an extended period of time when the liposomes are introduced epidurally as a single dose for sustained analgesia.
Inventor(s):	Gruber; Andres (San Diego, CA), Murdande; Sharad B. (San Diego, CA), Kim; Taehee (San Diego, CA), Kim; Sinil (Solana Beach, CA)
Assignee:	Depotech Corporation (San Diego, CA)
Application Number:	08/502,569
Patent Claims:	1. A method for epidural administration to a vertebrate of a therapeutic compound comprising encapsulating a therapeutic compound in a multivesicular liposome formulation comprising less than 10 weight percent by volume of a phospholipid and having a sustained release rate of the compound, and introducing said formulation epidurally to the vertebrate. 2. The method of claim 1 wherein the vertebrate is a mammal. 3. The method of claim 2 wherein the mammal is a human. 4. The method of claim 1 wherein the therapeutic compound is an opioid. 5. The method of claim 4 wherein the opioid is morphine sulfate. 6. The method of claim 4 wherein the opioid is hydromorphone. 7. The method of claim 1 wherein the therapeutic compound is an opiate antagonist. 8. The method of claim 7 wherein the opiate antagonist is selected from the group consisting of naloxone and naltrexone. 9. The method of claim 1 wherein the therapeutic compound is a neurotrophic factor. 10. The method of claim 9 wherein the neurotrophic factor is selected from the group consisting of an insulin-like growth factor, a ciliary neurotrophic factor, a nerve growth factor, dopamine, epinephrine, norepinephrine, gamma-amino butyric acids and neostigmine. 11. The method of claim 1 wherein formulation is introduced via an epidural catheter inserted into the epidural space. 12. The method of claim 11 wherein the epidural catheter is inserted downwards from the cervical region. 13. The method of claim 1 wherein the formulation is administered as a single dose. 14. The method of claim 1 wherein the formulation is a dispersion system. 15. The method of claim 1 wherein the therapeutic compound is a peptide or peptidomimetic. 16. The method of claim 1 wherein the therapeutic compound is selected from the group consisting of codeine, hydrocodone, levorphanol, oxycodone, oxymorphone, diacetyl morphine, buprenorphine, nalbupine, butorphanol, pentazocine, methadone, fentanyl, sufentanyl, and alfentanyl. 17. The method of claim 1 wherein the therapeutic compound is selected from the group consisting of enkephalins, endorphins, casomorphin, kyotorphin, and their bioactive fragments. 18. The method of claim 1 wherein the formulation is introduced via a hypodermic needle inserted into the epidural space. 19. A method for ameliorating respiratory depression in a patient administered an analgesic compound comprising epidurally administering to the patient one and only one dose of an analgesic compound encapsulated in a multivesicular liposome formulation comprising less than 10 weight percent by volume of a phospholipid. 20. The method of claim 19 wherein the analgesic compound is an opioid. 21. The method of claim 20 wherein the opioid is morphine sulfate. 22. The method of claim 21 wherein the dose contains from about 1 mg to about 60 mg of morphine sulfate. 23. The method of claim 20 wherein the opioid is selected from the group consisting of hydromorphone, codeine, hydrocodone, levorphanol, oxycoone, oxymorphone, diacetyl morphine, buprenorphine, nalbupine, butorphanol, pentazocine, methadone, fentanyl, sufentanyl and alfentanyl, and suitable combinations thereof.