Biphasic lipid-vesicle compositions
A biphasic lipid vesicle composition for treating cervical displasia by intravaginal delivery. The composition includes a suspension of lipid-bilayer vesicles having entrapped therein, an oil-in-water emulsion, human interferon alpha-2b and L-methionine, the composition having an interferon alpha-2b specific activity of between about 1-10 MIU (million international units) per gram composition, and between 0.01 to 0.5 weight percent L-methionine. In the treatment method, the composition is administered at a dose of between about 1-20 MIU interferon alpha-2b, and this dose is administered at least 3 days/week, for a period of at least 4 weeks.
1. A biphasic vesicle composition comprising:
(a) a first phase comprising an oil-in-water emulsion which itself comprises oil, water, interferon alpha-2b and methionine; and
(b) a second phase comprising multilamellar lipid vesicles suspended in said first phase wherein said vesicles contain entrapped therein a composition comprising an oil-in-water emulsion which itself comprises oil, water, interferon alpha-2b and methionine,
wherein each phase comprises an amount sufficient of methionine to stabilize said interferon alpha-2b against oxidation,
wherein said methionine is the amino acid methionine of the chemical structure:
further wherein said composition comprises a therapeutically effective aggregate amount of said interferon alpha-2b.
2. The biphasic vesicle composition of claim 1 , wherein said oil-in-water emulsion is comprised of oil droplets having a size of from about 0.1 μm to 1 μm.
3. A biphasic vesicle composition of claim 1 , wherein said methionine is present in a concentration of from 0.01 to 0.5 weight percent.
4. The biphasic vesicle composition of claim 1 , wherein at least 30% of said interferon alpha-2b and said methionine is entrapped within said vesicles as part of said oil-in-water emulsion.
5. The biphasic vesicle composition of claim 2 , wherein at least 30% of said interferon alpha-2b and said methionine is entrapped within said vesicles as part of said oil-in-water emulsion.
6. The biphasic vesicle composition of claim 3 , wherein at least 30% of said interferon alpha-2b and said methionine is entrapped within said vesicles as part of said oil-in-water emulsion.
7. The biphasic composition of claim 1 , wherein said multilamellar vesicle comprises from about 2 to about 4 weight percent cholesterol.
8. The biphasic composition of claim 1 , wherein said methionine used in each phase is L-methionine.
9. The biphasic composition of claim 1 , wherein said interferon alpha-2b is human interferon alpha-2b.