O/W type emulsion
The present invention provides an O/W type emulsion having a volume median diameter of not more than 100 nm and containing a compound represented by the formula (1) wherein X a and X b are each independently X 1 , X 2 or a 1,4-piperazinediyl group; s is 1 or 2, R 4 is an alkyl group having 1-6 carbon atoms, n a and n b are each independently 0 or 1, R 1a , R 1b , R 2a and R 2b are each independently an alkylene group having 1-6 carbon atoms, Y a and Y b are each independently an ester bond, or the like, and R 3a and R 3b are each independently a liposoluble vitamin residue or the like.
1. An O/W type emulsion having a volume median diameter of not more than 100 nm and comprising a compound represented by the formula (1)
wherein X a and X b are each independently X 1 , X 2 or 1,4-piperazinediyl group;
s is 1 or 2,
R 4 is an alkyl group having 1-6 carbon atoms,
n a and n b are each independently 0 or 1,
R 1a and R 1b are each independently an alkylene group having 1-6 carbon atoms,
R 2a a and R 2b are each independently an alkylene group having 1-6 carbon atoms,
Y a and Y b are each independently an ester bond, an amide bond, a carbamate bond, an ether bond or a urea bond,
R 3a and R 3b are each independently a sterol residue, a liposoluble vitamin residue or an aliphatic hydrocarbon group having 12-23 carbon atoms,
the sterol residue is a residue derived from cholesterol, cholestanol, stigmasterol, β-sitosterol, lanosterol, ergosterol, cholesterol hemisuccinate, or cholesterol hemiglutarate, and
the liposoluble vitamin residue is a residue derived from retinoic acid, retinol, retinal, ergosterol, 7-dehydrocholesterol, calciferol, cholecalciferol, dihydroergocalciferol, dihydrotachysterol, tocopherol, tocotrienol, tocopherol hemisuccinate, or tocopherol hemiglutarate, and
encapsulating a drug having a water/octanol distribution coefficient Log Pow of not less than 5.
2. The O/W type emulsion according to claim 1 , wherein the volume median diameter is 30-50 nm.
3. The O/W type emulsion according to claim 1 , further comprising at least one selected from the group consisting of phospholipid, cholesterol and PEG lipid.
4. The O/W type emulsion according to claim 1 , wherein the drug is 4-methylumbelliferone cholesterol hemisuccinate or dexamethasone cholesterol hemisuccinate.
5. A method for delivering a drug having a water/octanol distribution coefficient Log Pow of not less than 5 into a cell, comprising contacting the O/W type emulsion according to claim 1 with the cell.
6. The method according to claim 5 , wherein the O/W type emulsion is brought into contact with the cell in vitro.
7. The method according to claim 5 , wherein the O/W type emulsion is brought into contact with the cell by administration to a body.
8. The O/W type emulsion according to claim 2 , wherein the drug is 4-methylumbelliferone cholesterol hemisuccinate or dexamethasone cholesterol hemisuccinate.
9. The O/W type emulsion according to claim 2 , further comprising at least one selected from the group consisting of phospholipid, cholesterol and PEG lipid.
10. The O/W type emulsion according to claim 9 , wherein the drug is 4-methylumbelliferone cholesterol hemisuccinate or dexamethasone cholesterol hemisuccinate.