| abstract |
Phospholipid derivatives represented by the following general formula (1) have high safety against a living body and can be suitably used in drug delivery systems such as liposomes.n n n (One)n n n Wheren n n R 1 CO and R 2 CO are each independently acyl groups having 8 to 22 carbons;n n n a is each independently an integer of 0 to 5;n n n b are each independently 0 or 1;n n n M is hydrogen atom, alkali metal atom, ammonium or organic ammonium;n n n [PG] k is a residue of polyglycerol of degree of polymerization k; And,n n n k, k1, k2 and k3 aren n n 2≤k≤50,n n n 1≤k1≤ (k + 2) / 2,n n n k2≥0,n n n k1 + k2 + k3 = k + 2. |