the present invention is directed to a composition comprising ( a ) cabazitaxel and ( b ) sulfobutyl ether beta cyclodextrin (“ sbecd ”). typically , the weight ratio of cabazitaxel to sbecd is between 1 : 30 and 1 : 1000 ; preferably , such ratio is between 1 : 90 and 1 : 200 . in one particularly preferred embodiment the composition of this invention comprises cabazitaxel and sbecd in weight ratio around 1 : 133 . such composition may optionally further comprise additional components added to improve its pharmaceutical properties . in particular , an acid , a base , and / or a salt can be added to the composition to adjust the ph and the tonicity of the composition . it is particularly preferred that hcl , naoh , citric acid and nacl are used to adjust the ph and the tonicity of the composition . in certain embodiments the composition is a sterile liquid aqueous solution suitable for administration by intravenous injection or infusion and comprises between 0 . 5 % and 70 % sbecd , preferably between 1 % and 40 % sbecd , and more preferably between 2 % and 20 % sbecd . in other embodiments the composition of this invention is in the form of sterile solid lyophilizate or in the form of an aqueous solution comprising between 2 % and 70 % sbecd , preferably between 20 % and 60 %; both of which forms are suitable for storage . the compositions of this invention may be prepared by mixing cabazitaxel with an aqueous solution of sbecd . such compositions are typically mixed at room temperature , although higher or lower temperatures may be employed . the mixture is then typically filtered and stored . if desired the filtered solution may be freeze dried for storage . excess of cabazitael was mixed with aqueous sbecd solutions for 16 hours at 23 ° c . the resulting suspension was filtered through a 0 . 22 μm filter , and the clear filtrate solution was analyzed by hplc . the concentration of cabazitaxel in solutions is presented in the table below . a solution containing 2 . 02 mg / ml cabazitaxel in 20 % aqueous sbecd was prepared by sequential dissolving sbecd in water , and cabazitaxel in the resulting solution , followed by filtration through a 0 . 22 μm filter . portions of the solution was subsequently diluted with water to form three solutions comprising 1 %, 4 . 8 % and 10 % sbecd , respectively . the solutions were incubated at temperature 23 ° c . and at selected time points were analyzed using the hplc . the results are presented in the table below . all solutions were stable . 2180 mg of sbecd was dissolved in 8707 mg of distilled water . 16 . 4 mg cabazitaxel was added into this solution and mixed until completely dissolved . the solution was filtered through a 0 . 22 μm filter . the solution of the example 3 was frozen quickly using dry ice . the frozen material was freeze dried . 9 . 80 ml of 0 . 9 % aqueous nacl was added to 200 mg of the lyophilized composition of the example 3 . the mixture was gently mixed to produce clear a solution comprising 0 . 15 mg / ml cabazitaxel solution in 2 % sbecd with 0 . 9 % nacl . female sprague - dawley rats , 8 animals per group , received 1 hour i . v . infusion of solution of the example 3 , or solution comprising cabazitaxel , polysorbate 80 , ethanol and water , equivalent to the commercial composition of cabazitaxel . both compositions were administered at the dose 8 mg / kg . blood samples were collected at 0 . 5 , 1 , 1 . 08 , 1 . 25 , 1 . 5 , 2 , 3 , and 4 hours post beginning of the infusion ; three samples from each animal were taken during the sampling . plasma levels of cabazitaxel in each sample were determined using hplc . the results are presented in the table below . the results demonstrate that the solution of the example 3 and the solution equivalent to the commercial composition of cabazitaxel provide equivalent exposure to cabazitaxel . c57bl / 6 mice were inoculated i . v . with murine 3ll cells ( 200 , 000 ) and treated with i . v . injection of 10 mg / kg of solution of the example 3 , or solution comprising cabazitaxel , polysorbate 80 , ethanol and water , equivalent to the commercial composition of cabazitaxel , on day 1 , 4 and 7 after inoculation . saline injection was used in the control group . mice body weights were recorded to evaluate tolerability to the treatment . no mortalities were recorded . the animals were sacrificed on day 18 and the metastases in lungs were counted . the results are presented in the table below . mda - mb - 231 cells ( 500 , 000 cells per site ) in cell culture medium containing 30 % matrigel were subcutaneously inoculated at 2 sides of the flank ( in the mid - flank ) of nude balb / c mice . after 16 days , when tumors reached 0 . 5 - 0 . 8 cm , the animals were randomly divided to three groups and treated on day 1 , 4 and 7 with saline ( control ) or with 7 . 5 mg / kg of solution of the example 3 , or solution comprising cabazitaxel , polysorbate 80 , ethanol and water , equivalent to the commercial composition of cabazitaxel . the tumor sizes and body weights were recorded during study , and tumors were removed and weighted upon study termination . the results are presented in the tables below . human prostate carcinoma du - 145 cells ( 2 , 000 , 000 cells per site ) in cell culture medium containing 50 % matrigel were subcutaneously inoculated at 2 sides of the mid - flank of scid mice . after 21 days ( when tumors reached 0 . 5 - 0 . 8 cm ) the animals were randomly divided to three groups and treated on day 1 , 4 and 7 after that with saline ( control ) or with 7 . 5 mg / kg of solution of the example 3 , or solution comprising cabazitaxel , polysorbate 80 , ethanol and water , equivalent to the commercial composition of cabazitaxel . the tumor sizes and body weights were recorded . the results are presented in the tables below .
the present invention is directed to a composition comprising cabazitaxel and sulfobutyl ether beta cyclodextrin . such composition exhibits unexpectedly desirable stability in aqueous media , permitting therapeutic dosages of the drug to be administered without the use of either ethanol or surfactants .