Patent ID: 11964050
Assignee: PHARMOSA BIOPHARM INC.
Field: Pharmaceuticals (Chemistry)
Classification: CPC A | IPC A

Claim 11:
12. A pharmaceutical composition, comprising liposomes, said liposomes comprising:
a lipid bilayer formed of a first phospholipid and a second phospholipid, wherein the first phospholipid is hydrogenated soy phosphatidylcholine (HSPC) and the second phospholipid is PEG-DSPE; and
an internal aqueous medium inside the lipid bilayer, the internal aqueous medium comprising a bicarbonate salt with a concentration about 50 mM to about 800 mM and a weak acid drug, said weak acid drug is Iloprost or treprostinil,, wherein the liposomes are suspended in an external medium, the pH of the external medium is above the pKa of the weak acid drug and less than about 7,, wherein the external medium is substantially free of bicarbonate salt such that there is less than 2% or without bicarbonate salt and the encapsulation efficiency of the weak acid drug is at least 80%, and, wherein the molar ratio of the weak acid drug to the bicarbonate salt is from about 0.1:1 to about 0.8:1.