LIPOSOMAL FORMULATIONS OF AMIDINE SUBSTITUTED BETA-LACTAM COMPOUNDS FOR USE IN THE TREATMENT OF BACTERIAL INFECTIONS

1 . A liposomal pharmaceutical formulation comprising a compound according to formula (I) as active ingredient,

characterized in that

R 1 and R 2 represent methyl,

R 3 represents —O—(SO 2 )OH,

X represents CH,

Z represents a two carbon alkyl-chain, substituted with a carboxy substituent,

Y represents O,

represents 0

A represents phenyl substituted with a substituent of the following formula

wherein

R 1b and R 2b represent hydrogen,

R 3b represents aminoethyl, azetidine, pyrrolidine or piperidine,

Q represents a bond,

* is the linkage site to the residue represented by A, and

and the salts thereof, the solvates thereof and the solvates of the salts thereof,

wherein the liposomes comprise at least one phospholipid and one steroid.

2 . The liposomal pharmaceutical formulation according to claim 1 , wherein the active ingredient is at least one member of the group of compounds selected from formulae (I-a) to (I-g):

3 . The liposomal pharmaceutical formulation according to claim 1 , wherein the active ingredient is a compound of formula (I-g).

4 . The liposomal pharmaceutical formulation according to claim 1 , wherein the phospholipid is selected from the group comprising phosphotidylcholine, phosphotidylserine, Phosphotidylethanolamine, phosphoinositol, 1,2-dilauroyl-sn-Glycero-3-Phosphocholine, 1,2-dioleoyl-sn-Glycero-3 [Phospho-L-Serine] sodium salt, dipalmitoylphosphotidylcholine, distearoylphosphotidylcholine, dipalmitoylphosphotidylserine, dipalmitoylphosphotidylglycerol, 1-stearoyl-2-linoleoyl-sn-glycero-3-[phosphor-L-serine] sodium salt, dioleoylphosphotidylcholine, and sphingomyelin.

5 . The liposomal pharmaceutical formulation according to claim 1 , wherein the steroid is selected from the group comprising cholesterol, derivatives of cholesterol, and polymer-derivatized cholesterol.

6 . The liposomal pharmaceutical formulation according to claim 1 , wherein the phospholipid is distearoylphosphotidylcholine.

7 . The liposomal pharmaceutical formulation according to claim 1 , wherein the steroid is cholesterol.

8 . The liposomal pharmaceutical formulation according to claim 1 , wherein the ratio of phospholipid to steroid is in the range from 60:40 to 40:60.

9 . The liposomal pharmaceutical formulation according to claim 1 , wherein the ratio of phospholipid to steroid is 55:45.

10 . The liposomal pharmaceutical formulation according to claim 1 , wherein the lipid to drug ratio is in the range of 1:0.1 to 1:0.5.

11 . The liposomal pharmaceutical formulation according to claim 1 , wherein the lipid to drug ratio is 1:0.3.

12 . The liposomal pharmaceutical formulation according to claim 1 , for use in the treatment and/or prevention of bacterial infections.

13 . A method of treatment and/or prevention of bacterial infection comprising administering a lipid formulation according to claim 1 .