Note: Descriptions are shown in the official language in which they were submitted.
- ` ~14070~
RAN 441 0/240
The present invention is concerned with aqueous liposome
5 solutions which contain a ~-lactamase inhibitor.
It has been found that the residence time of ~-lactamase
inhibitors, such as tazobactam, in the body is increased when the
~-lactamase inhibitor is administered in the form of an aqueous
10 liposome solution. Furthermore, it has been found that the resid-
ence time in the plasma of the ~-lactamase inhibitor administ-
ered in such a form can be influenced by the size of the
liposomes.
The liposomes of the compositions in accordance with the
invention can be composed of substances which are known as
liposome formers. Preferably, the liposomes consist of
phosphatidylcholine, such as egg lecithin or soya lecithin, and
phosphatidylglycerol and, if desired, cholesterol. The phosph-
20 atidylcholine:phosphatidylglycerol molar ratio is conveniently
10:0-1, preferably 10:1. The phosphatidylcholine:cholesterol
molar ratio is conveniently 10:0-5, preferably 10:5. The
concentration of the liposome former (i.e. phosphatidylcholine,
phosphatidylglycerol and cholesterol) in the liposome solution is
2 5 conveniently about 10-400 mg/ml, preferably about 100-
250 mg/ml.
The term N,~-lactamase inhibitor" denotes substances which
inhibit the enzymatic cleavage of the ,~-lactam ring of ~-lactam
3 0 antibiotics, such as penicillins, cephalosporins, monolactams and
carbapenems. Tazobactam, sulbactam and clavulanic acid are
examples of ,B-lactamase inhibitors. Examples of other ,B-lactam-
ase inhibitors are the compounds described in European Patent
Publication A-0 508 234, especially the compounds
benzyl (1 S,5R)-7-oxo-6-sulpho-2,6-diazabicyclo[3.2.0]-
heptane-2-carboxylate,
(1 S,5R)-2-[(Z)-3-a-acetamidocinnamoyl]-7-oxo-2,6-
Grn/So 21.11.94
2140701
diazabicyclo[3.2.0]heptane-6-sulphonic acid,
(R/S)-a-(1 S,5R)-2-[2-carboxy-2-(3-thienyl)acetyl]-7-oxo-
2,6-diazabicyclo[3.2.0]heptane-6-sulphonic acid,
(1 S,5R)-7-oxo-2-(3-pyridylacetyl)-2,6-diazabicyclo[3.2.0]-
5 heptane-6-sulphonic acid,
(1 S,5R)-2-[(R,S)-2-indolylcarbonyl]-7-oxo-2,6-diaza-
bicyclo[3.2.0]heptane-6-sulphonic acid,
(1 S,5R)-2-[(R)-a-hydroxyphenylacetyl]-7-oxo-2,6-diaza-
bicyclo[3.2.0]heptane-6-sulphonic acid,
1 0(1 S,5R)-2-[(S)-a-hydroxyphenylacetyl]-7-oxo-2,6-diaza-
bicyclo[3.2.0]heptane-6-sulphonic acid,
R(a)-[[(1 S,5R)-7-oxo-6-sulpho-2,6-diazabicyclo[3.2.0]hept-
2-yl]carbonyl]benzyl sulphate,
(1 S,5R)-2-(2-amino-4-thiazoleglyoxyloyl)-7-oxo-2,6-
15 diazabicyclo[3.2.0]heptane-6-sulphonic acid
(1 S,5R)-7-oxo-2-(D-2-phenylglycyl)-6-sulpho-2,6-diaza-
bicyclo[3.2.0]heptane-6-sulphonic acid,
(1 S,5R)-7-oxo-2-(L-2-phenylglycyl)-6-sulpho-2,6-diaza-
bicyclo[3.2.0]heptane-6-sulphonic acid,
20(1 S,5R)-7-oxo-2-L-tyrosyl-2,6-diazabicyclo[3.2.0]heptane-
6-sulphonic acid,
(1 S,5R)-2-[D-2-(p-hydroxyphenyl)glycyl]-7-oxo-2,6-diaza-
bicyclo[3.2.0]-heptane-6-sulphonic acid,
(1 S,5R)-7-oxo-2-L-tryptophanyl-2,6-diazabicyclo]3.2.0]-
2 5 heptane-6-sulphonic acid,
(1 S,5R)-2-[(R or S)-a-amino-(2-thienyl)acetyl]-7-oxo-2,6-
diazabicyclo-[3.2.0]heptane-6-sulphonic acid
(1 S,5R)-7-oxo-2-(phenylcarbamoyl)-6-sulpho-2,6-diaza-
bicyclo[3.2.0]heptane,
3 0(1 S,5R)-2-(benzylcarbamoyl)-7-oxo-6-sulpho-2,6-diaza-
bicyclo[3.2.0]heptane,
(1 S,5R)-7-oxo-2-(N-phenylglycyl)-2,6-diazabicyclo[3.2.0]-
heptane-6-sulphonic acid,
(1 S,5R)-2-[(E)-3-(2-furyl)acryloyl]-7-oxo-2,6-diaza-
3 5 bicyclo[3.2.0]heptane-6-sulphonic acid,
(1 S,5R)-2-[N-(m-aminophenyl)glycyl]-7-oxo-2,6-diaza-
bicyclo[3.2.0]-heptane-6-sulphonic acid,
(1 S,5R)-2-[[(1 -methyl-1 H-tetrazol-5-yl)thio]acetyl]-7-
2140701
oxo-2,6-diazabicyclo[3.2.0]heptane-6-sulphonic acid,
(1 S,5R)-2-[[(1 H-benzotriazol-1 -yl)thio]acetyl]-7-oxo-2,6-
diazabicyclo-[3.2.0]heptane-6-sulphonic acid and
(1 S,5R)-2-[(E)-3-(3-indolyl)acryloyl]-7-oxo-2,6-diaza-
5 bicyclo]3.2.0]heptane-6-sulphonic acid,
as well as pharmaceutically compatible salts of these compounds.
Further ~-lactamase inhibitors which can be present in the
liposome solutions in accordance with the invention are the
10 compounds of general formula l
()n
R2
CooR3
wherein one of R1 and R2 signifies -COR4, -CN, -CH2OR5 or
-SO2R6 and the other signifies H, -COR4, -CN, -CH2OR5 or
-SO2R6 or lower alkyl;
R3 = H, lower alkyl, aryl-alkyl, allyl or a residue which is
cleavable in vivo;
R4 = H, lower alkyl, lower alkoxy, benzyloxy, amino or lower
alkylamino;
R5 = H or-CONH2;
R6 = lower alkyl and
n = 0, 1 or 2
as well as the pharmaceutically compatible salts of these
25 compounds, especially the compounds
benzhydryl (E/Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-
7-oxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-
30 4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate,
benzhydryl (Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-
4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate,
sodium (E)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-4,4,7-
trioxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2-carboxylate,
~140~U~
sodium (Z)-(2S,3S,5R)-3-(2-cyanoethenyl)-3-methyl-4,4,7-
trioxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2-carboxylate,
benzhydryl (E/Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-
methyl-7-oxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2-carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-
methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2-
carboxylate,
benzhydryl (Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-
methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-
1 0 carboxylate,
sodium (E)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl-
4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate,
sodium (Z)-(2S,3S,5R)-3-(2-carbamoyl-vinyl)-3-methyl-
4,4 ,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3-
methyl-7-oxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2-carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3-
methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-
carboxylate,
sodium (E)-(2S,3S,5R)-3-(2-ethoxycarbonyl-vinyl)-3-
methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-
carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-benzyloxycarbonyl-vinyl)-
3-methyl-7-oxo-4-thia-1 -aza-bicyclo[3 .2.0]heptane-2- 5 carboxylate,
benzhydryl (E)-(2S,3S,5R)-3-(2-benzyloxycarbonyl-vinyl)-
3-methyl-4,4,7-trioxo-4-thia-1 -aza-bicyclo[3.2.0]heptane-2-
carboxylate, and
sodium (E)-(2S,3S,5R)-3-(2-benzyloxycarbonyl-vinyl)-3-
30 methyl-4,4,7-trioxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-
carboxylate.
The concentration of the ~-lactamase inhibitor in the
liposomes depends on the specific ,~-lactamase inhibitor and must
35 be determined on a case by case basis. Too high active substance
concentrations can lead, after administration of the liposomes, to
rupture of the liposomes (osmotic effect) in the bloodstream or
in the tissue. For example, the tazobactam concentration in the
21~070~
liposomes is conveniently not more than 0.2 mg/mg liposome
former and is preferably about 0.1 to 0.15 mgtmg liposome
former.
It has been found that the size of the liposomes influences
the residence time (i.e. the half-life) of the ,B-lactamase inhibitor
in plasma. In order to achieve a long residence time the diameter
of the liposomes should be smaller than about 250 nm. Lipo-
somes having a diameter of about 100-200 nm, especially about
10 150 nm, are preferred in accordance with the invention.
The liposome solutions in accordance with the invention can
be administered parenterally, e.g. intravenously, intramuscularly
or subcutaneously, taking into consideration the administration
15 guidelines known for the active substance contained therein.
They can contain adjuvants which are usually used in pharma-
ceutical liposome solutions for parenteral administration,
especially stabilizers such as a sugar, e.g. sucrose or trehalose,
as well as agents for adjusting the pH and the osmotic pressure.
20 Furthermore, the liposome solutions in accordance with the
invention can contain ,~-lactam antibiotics, especially penicillins
or cephalosporins, e.g. piperacillin or apalcillin; or such as e.g.
ceftriaxone, ceftazid or cefoperazone; or a carbapenem, such as
imipenem or meropenem; or a monobactam, such as aztreonam.
25 Further, they can be present in Iyophilized form.
The liposome solutions in accordance with the invention can
be manufactured in a manner known per se, for example by
preparing a solvent-free film from the liposome formers using a
3 0 suitable solvent, e.g. chloroform/methanol, hydrating this film
with an aqueous solution of the ,~-lactamase inhibitor and
converting the thus-obtained multilamellar vesicle into
liposomes of the desired dimension by extrusion.
3 5 The following Examples illustrate the invention.
21gO70~
Fxample 1
50 mg of a mixture of egg lecithin (Lipoid E PC, Lipoid KG,
Ludwigshafen, Germany), phosphatidylglycerol (Lipoid PG,
5 16:0/16:0, Lipoid KG, Ludwigshafen, Germany) and cholesterol in
the molar ratio of 10:1:5 were dissolved in chloroform/methanol
(1:1 parts by vol.) in a round flask. The solvent was removed in a
rotating flask at 40C under reduced pressure (finally at 0.01
mbar). The residual film was treated with 1 ml of a 10% aqueous
10 solution of tazobactam Na and hydrated by treatment in a vortex
mixer. The thus-obtained multilamellar tazobactam-containing
vesicles were pressed three times under nitrogen pressure (6-
8 bar) through a 0.2 ~lm and once or twice through a 0.1 ~lm
polycarbonate filter (Nucleopore, Pleasanton, CA., USA). The
15 thus-obtained liposomes had an average diameter of 150nm
(measured by quasi-elastic light scattering with a Nano-Sizer
PSM 78, Coulter Electronics, Krefeld, Germany). Liposomes having
a larger or smaller diameter can be manufactured analogously by
choosing a filter of larger (e.g. 0.4 llm) or smaller (e.g. 0.05 ~m)
20 pore size.
Fxam~le ~
Tazobactam liposomes (1 ml/kg, 5.8-10.4 mg tazobactam/
25 kg) of various sizes were injected into male albino rats through a
jugular vein catheter. After rinsing the catheter with physio-
logical saline plasma samples were removed through the catheter
at various intervals, with the plasma withdrawn being replaced
by saline solution. The tazobactam concentration in the samples
30 was determined by HPLC. The results are reproduced hereinafter:
Formulation Liposome t 1/2 AUC
diameter [h] [mg.h/ml]
[nm]
Liposomes 146 5.0i1.9 456.3i250.1
Liposomes 236 1.4+0.3 135.1i 62.5
Aqueous
solution 0.14 5.27
21~0701
The above results show that by administration in the form
of a liposome solution the residence time of the active substance
in plasma was increased and that this effect was stronger in the
5 case of solutions with smaller liposomes than with larger
liposomes.
