Production of multivesicular liposomes
View Patent ↗Multivesicular liposomes are prepared at commercial scales by combining a first w/o emulsion with a second aqueous solution to form a w/o/w emulsion using a static mixer. Solvent is removed from the resulting emulsion to form multivesicular liposome-containing compositions. Further optional process steps include primary filtration and secondary cross-flow filtration. The products produced according to the processes of the invention can be produced through a series of aseptic steps.
1. A process for preparing a multivesicular liposomal particle composition of pre-determined, uniform size distribution, the process comprising:
a) providing a first emulsion by mixing a first aqueous phase and a volatile water-immiscible solvent phase, said solvent phase comprising at least one amphipathic lipid and at least one neutral lipid;
b) mixing and emulsifying said first emulsion and a second aqueous phase in a mixer to provide a second emulsion, said second emulsion comprising a continuous aqueous phase;
c) sparging the volatile water-immiscible solvent from the second emulsion to form an aqueous suspension of multivesicular liposomal particles by bubbling an inert gas through the second emulsion using at least one sparge ring, at least one sparge tube or at least one fit;
d) primary filtration of the aqueous suspension of multivesicular liposomal particles by cross-flow filtration using a filter to exchange the second aqueous phase with an aqueous component to provide an initial volume of aqueous media, wherein the filter has a membrane pore size from 0.07 to 0.45 μm;
e) secondary filtration by cross-flow filtration to reduce the initial volume to provide a subsequent volume of aqueous media that is 10% to 90% of the initial volume, further wherein the cross-flow filtration is carried out with a process-scale tangential flow filter with a filtration area of 23 square feet or more, wherein all steps are carried out under aseptic conditions,
f) the composition is prepared in quantities or batches greater than a liter; wherein the first emulsion is mixed in a first emulsification vessel of at least 10 liters in volume; and
g) wherein the uniform size distribution has a number weighted mean particle size of at least 10 microns.
2. The process of claim 1 , wherein the sparging comprises at least two steps having different flow rates.
3. The process of claim 1 , wherein the volume ratio of the first aqueous phase to the water-immiscible solvent phase is from 0.33 to 1.6.
4. The process of claim 1 , wherein the volume ratio of the first emulsion to second aqueous phase is from 0.01 to 0.5.
5. The process of claim 1 , wherein the volume ratio of the first aqueous phase to the water-immiscible solvent phase is from 0.33 to 1.6; and, the volume ratio of the first emulsion to second aqueous phase is from 0.01 to 0.5.
6. The process of claim 1 , wherein the filter is a hollow fiber filter.
7. The process of claim 1 , wherein the sparging comprises passing an inert gas through at least one sparge ring.
8. The process of claim 1 , wherein the inert gas is nitrogen or argon.
9. The process of claim 6 , wherein the filter has a membrane pore size from 0.1 μm to 0.2 μm.
10. The process of claim 1 , wherein the first emulsification vessel further comprises a water jacket.
11. The process of claim 1 , wherein the first emulsification vessel is 10 liters in volume.
12. The process of claim 1 , wherein the first emulsification vessel is 20 liters in volume.
13. The process of claim 1 , wherein the first emulsification vessel is 25 liters in volume.
14. The process of claim 1 , wherein the first emulsification vessel is 75 liters in volume.
15. The process of claim 1 , wherein the first emulsification vessel is 100 liters in volume.
16. A process for preparing a multivesicular liposomal particle composition of pre-determined, uniform size distribution, the process comprising:
a) primary filtration by cross-flow filtration of an aqueous suspension of multivesicular liposomal particles by cross-flow filtration; and
b) secondary filtration by cross-flow filtration of the aqueous suspension to reduce the initial volume to provide a subsequent volume of aqueous media that is 10% to 90% of the initial volume, wherein all steps are carried out under aseptic conditions.
17. The process of claim 16 , where in the primary and secondary filtration is carried out with one or more hollow fiber filters.
18. The process of claim 17 , wherein the one or more filters have a membrane pore size from 0.1 microns to 0.2 microns.
19. The process of claim 18 , wherein the uniform size distribution has a number weighted mean particle size of at least 10 microns.
20. The process of claim 17 , wherein the one or more filters are fluidly connected to a retentate vessel containing the aqueous suspension to be filtered.
21. The process of claim 20 , wherein the retentate vessel is at least 10 liters in volume.
22. The process of claim 21 , wherein the retentate vessel further comprises a water jacket.
23. The process of claim 21 , wherein the retentate vessel is 10 liters in volume.
24. The process of claim 22 , wherein the retentate vessel is 20 liters in volume.
25. The process of claim 21 , wherein the retentate vessel is 25 liters in volume.
26. The process of claim 21 , wherein the retentate vessel is 75 liters in volume.
27. The process of claim 21 , wherein the retentate vessel is 100 liters in volume.
28. A process for preparing a multivesicular liposomal particle composition, the process comprising:
a) providing a volume of first emulsion by mixing a volume of a first aqueous phase and a volume of a volatile water-immiscible solvent phase, said solvent phase comprising at least one amphipathic lipid and at least one neutral lipid;
b) mixing and emulsifying said first emulsion and a volume of a second aqueous phase in a high shear mixer to provide a volume of a second emulsion, said second emulsion comprising a continuous aqueous phase; and
c) removing the volatile water-immiscible solvent from the second emulsion to form a volume of multivesicular liposomal particle composition, wherein said solvent removal comprises contacting the second emulsion with an inert gas flow; and
wherein said process further comprises primary filtration of the multivesicular liposomal particle composition by cross-flow filtration using a filter having a membrane where the multivesicular liposomal particle composition does not pass through the membrane;
wherein all steps are carried out under aseptic conditions, and wherein all solutions are sterile filtered, and wherein the multivesicular liposomal particle composition is immediately suitable for administration into humans; and
wherein the primary filtration comprises:
a first concentration of the multivesicular liposomal particle composition; and
a buffer exchange, resulting in a pH of the multivesicular liposomal particle composition of between about 5 and about 8, and the primary filtration is conducted at a transmembrane pressure of from about 0.1 psi to about 7 psi.
29. The process of claim 28 , wherein the mixer is a dynamic or static mixer.
30. The process of claim 28 , wherein the volume ratio of the first aqueous phase to the water-immiscible solvent phase is from about 0.33 to about 1.6.
31. The process of claim 28 , wherein the volume ratio of the first emulsion to the second aqueous phase is from about 0.05 to about 0.5.
32. The process of claim 28 , wherein the at least one amphipathic lipid is selected from the group consisting of phosphatidylcholines, phosphatidylethanolamines, sphingomyelins, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphati dylglycerols, phosphatidylserines, phosphatidylinositols, phosphatidic acids, cardiolipins, acyl trimethylammonium propane, diacyl dimethylammonium propane, and ethyl phosphati dylcholine.
33. The process of claim 28 , wherein the at least one neutral lipid is selected from the group consisting of glycerol esters, glycol esters, tocopherol esters, sterol esters, and squalenes.
34. The process of claim 28 , wherein the filter is a hollow fiber filter.
35. The process of claim 28 , further comprising potency adjustment of the multivesicular liposomal particle composition.
36. The process of claim 35 , wherein the potency adjustment is carried out by secondary filtration.
37. The process of claim 28 , wherein the multivesicular liposomal particle composition comprises an encapsulated physiologically active substance.
38. The process of claim 37 , wherein the physiologically active substance is selected from the group consisting of antianginas, antiarrhythmics, antiasthmatic agents, antibiotics, antidiabetics, antifungals, antihistamines, antihypertensives, antiparasitics, antineoplastics, antivirals, cardiac glycosides, hormones, immunomodulators, monoclonal antibodies, neurotransmitters, nucleic acids, proteins, radio contrast agents, radionuclides, sedatives, analgesics, steroids, tranquilizers, vaccines, vasopressors, anesthetics, peptides, prodrugs and pharmaceutically acceptable salts of the same.
39. The process of claim 38 , wherein the physiologically active substance is selected from cytarabine, insulin, paclitaxel, 5-fluorouracil, floxuridine, morphine, hydromorphine, dexamethasone, methotrexate, bleomycin, vincristine, vinblastine, IgF-1, bupivacaine and amikacin.
40. A process for preparing a multivesicular liposomal particle composition, the process comprising:
a) providing a volume of first emulsion by mixing a volume of a first aqueous phase and a volume of a volatile water-immiscible solvent phase, said solvent phase comprising at least one amphipathic lipid and at least one neutral lipid;
b) mixing and emulsifying said first emulsion and a volume of a second aqueous phase in a mixer to provide a volume of a second emulsion, said second emulsion comprising a continuous aqueous phase; and
c) removing the volatile water-immiscible solvent from the second emulsion to form a volume of multivesicular liposomal particle composition, wherein said solvent removal comprises contacting the second emulsion with an inert gas flow; and
wherein said process further comprises primary filtration of the multivesicular liposomal particle composition by cross-flow filtration using a filter having a membrane where the multivesicular liposomal particle composition does not pass through the membrane;
wherein the multivesicular liposomal particle composition is sterilized before filling, and wherein the multivesicular liposomal particle composition is immediately suitable for administration into humans; and
wherein the primary filtration comprises:
a first concentration of the multivesicular liposomal particle composition; and
a buffer exchange, resulting in a pH of the multivesicular liposomal particle composition of between about 5 and about 8, and the primary filtration is conducted at a transmembrane pressure of from about 0.1 psi to about 7 psi.
41. A multivesicular liposomal particle composition made by the process of claim 28 .
42. The process of claim 35 , wherein the volume of multivesicular liposomal particle composition is pooled and further processed by multiple batch processing.
43. The process of claim 28 , wherein the membrane is rated at 0.2 μm.