Abstract:
The invention relates to salts of 2-substituted quinolines, the manufacturing method for same, and use of the same for the production of drugs. Said salts are advantageous in that the same can be obtained in crystalline form, which facilitates their implementation in the manufacture of pharmaceutical compositions.

Description:
FIELD OF THE INVENTION 
     A subject matter of the invention is novel salts of 2-substituted quinolines, their process of manufacture and their use in the production of medicaments. These salts have the advantage of being able to be obtained in the form of crystals, which makes it easier to use them in the manufacture of pharmaceutical compositions. 
     BACKGROUND OF THE INVENTION 
     Substituted quinolines with varied structures have been described for their action with regard to the treatment of infections due to protozoa, such as leishmaniosis, trypanosomiasis or toxoplasmosis, and/or infections due to retroviruses, such as, for example, HIV or HTLV (WO 93/07125; WO 02/057238). 
     However, while some molecules among quinolines have shown an advantageous potential in the treatment of these pathologies, none has made it possible to date to result in the formulation of a medicament capable of being produced on the industrial scale. 
     This is because, in order to make possible such a development, a molecule must simultaneously exhibit a satisfactory in vivo pharmacological activity and a reduced toxicity but also physical and physicochemical qualities which allow it to be formulated under satisfactory conditions: ease of handling, stability over time, compatibility with the excipients and resistance to the storage conditions. 
     Certain physical properties are required in the case of active principles which have to be employed in medicaments provided in solid oral formulation forms. In the case in particular of medicaments intended for the treatment of tropical diseases, such as leishmaniosis and trypanosomiasis, certain medicaments have to be able to be stored under very restrictive temperature and humidity conditions without losing their effectiveness or decomposing. In addition, for economic reasons, it is desirable to be able to produce in the user countries the molecules intended for these treatments. It is thus necessary for these molecules, subjected to difficult climatic conditions, to exhibit and retain all the qualities required for the formulation of a medicament, for its manufacture on industrial devices and for its storage and its distribution in the targeted countries. 
     SUMMARY OF THE INVENTION 
     In point of fact, the inventors have found that some quinolines, the biological activity of which in the treatment of the abovementioned diseases is particularly noteworthy, exhibit the disadvantage of being difficult to handle in the formulation of medicaments, in particular medicaments for the oral route in solid formulation forms. 
     These quinolines are in particular those corresponding to the general formula (A): 
                                
in which R represents a C 2 -C 5  alkyl or alkenyl group optionally carrying one or more —OH functional groups.
 
     This is because these molecules are provided in the form of an oil and are therefore difficult, indeed even impossible, to formulate in the form of tablets or simple hard gelatin capsules containing mixtures of powders. 
     Generally, in particular in tropical countries, the formulation in the solid form in tablets or hard gelatin capsules confers, on the active principles and on the medicaments which contain them, a better stability, better preservation conditions and a greater ease of use than a formulation in the liquid form. In addition, these formulation forms are simpler to produce on the manufacturing devices which are more generally available locally. In addition, the administration of hard gelatin capsules or of tablets makes it possible to avoid underdosages or overdosages more easily than liquid forms. Optional recourse to mixtures of powders available in the form of sachets or of bottles for the reconstitution at the time of use of suspensions or solutions to be taken orally makes it possible, when necessary and for high unit doses per administration, to limit the risks of chemical decomposition which might occur in ready-for-use liquid forms. 
     Consequently one of the objects of the invention was to be able to obtain these compounds in a solid form, preferably a crystalline form, in order to allow them to be formulated under satisfactory conditions. In addition, these compounds must retain their biological activity and their low toxicity. 
     These objects could be attained by virtue of the discovery of certain salts of the molecules of formula (A). 
     The subject matter of the invention is the salts of the molecules (A) which are molecules corresponding to the formula (I) below: 
                                
in which:
 
X represents the camphorsulfonate anion or the anion of 7,7-dimethyl-2-oxobicyclo[2.2.1]heptane-1-methanesulfonic acid,
     R represents a linear, branched or cyclic C 2 -C 5  alkyl or alkenyl group optionally carrying one or more —OH functional groups.   

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an optical microscopy photograph of crystals of 2-(n-propyl)quinoline camsylate salt in reflected light, at magnification ×40; 
         FIG. 2  is an optical microscopy photograph of crystals of 2-(n-propyl)quinoline camsylate in polarized light at magnification ×81; 
         FIG. 3  is the superimposition of X-ray diffraction profiles of four batches of camsylate salt crystals that are in accordance with the present invention; 
         FIG. 4  shows the isotherms of the camsylate salt crystals for adsorption and for desorption of water at 25° C.; and 
         FIG. 5  is a powder X-ray diffraction profile of one of the camsylate salt batches shown in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Mention may in particular be made, among the molecules corresponding to the above formula (I), of the camphorsulfonic acid salts of
         2-(n-pentyl)quinoline,   2-(n-propyl)quinoline,   2-propenylquinoline,   2-(2-hydroxypropenyl)quinoline.       

     The invention is again characterized in that these molecules can be crystallized or recrystallized and thus obtained in the form of crystals which are more stable, easier to handle and easier to formulate in the form of tablets or hard gelatin capsules or powders (packaged in the form of sachets or bottles) intended in particular for the preparation at the time of use of suspensions or solutions to be taken orally. 
     In the case of 2-(n-propyl)quinoline, the crystalline form is characterized by the presence of the following peaks in the X-ray diffraction spectrum, measured on a diffractometer in theta-theta configuration, equipped with a copper anticathode and expressed in terms of interlattice distances d, of Bragg 2-theta angle and of relative intensity: 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                   
                 Interlattice 
                 Relative 
               
               
                 2-Theta 
                 distance d 
                 intensity 
               
               
                 angle (°)* 
                 (angström)** 
                 (%)*** 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 4.463 
                 19.78297 
                 79.1 
               
               
                 12.975 
                 6.81756 
                 89.3 
               
               
                 14.223 
                 6.22226 
                 49.6 
               
               
                 14.407 
                 6.14309 
                 100 
               
               
                 17.02 
                 5.20542 
                 56.7 
               
               
                 22.586 
                 3.93359 
                 71.4 
               
               
                   
               
               
                 *values ± 0.2° 
               
               
                 **values ± 0.2 Å 
               
               
                 ***values ± 0.5% 
               
             
          
         
       
     
     Another subject matter of the invention is a process for the manufacture, production, isolation and/or purification of a salt of formula (I) of a molecule of formula (A), in particular in the crystalline form or via a crystallization, this process comprising the following stages: 
     Use is made of the compound of formula (A) obtained by any process of the prior art. Camphorsulfonic acid in an equimolar amount is then added to this compound (A), so as to form the salt (I). It is possible, for example, to use the precursor 2-substituted quinoline compound (A) prepared by the process described in WO 93/07125 and to form the corresponding salt (I) by addition of camphorsulfonic acid in an equimolar amount. 
     The compound of formula (I) is then dissolved in a solvent chosen from acetone, methyl ethyl ketone, diethyl ketone, methanol, ethanol, propanol, isopropanol, ethyl ether or diisopropyl ether, at a concentration ranging from 0.05 to 60 g/l. 
     The solvent is advantageously brought to reflux and then the solution is cooled down to a temperature of between −30° C. and 30° C., in particular between 0 and ambient temperature, for example 20 to 25° C. 
     The solution can advantageously be seeded during the cooling stage, advantageously when it is at a temperature of between 0 and 4° C. 
     The crystals obtained are advantageously filtered off and optionally washed with diisopropyl ether. 
     The choice of the crystallization solvent or of the mixture of crystallization solvents and of the cooling rate can result in different crystalline forms for the same molecule. 
     In the case of 2-(n-propyl)quinoline, it is advantageously planned to dissolve it in a mixture of methanol and ethyl ether. An equimolar amount of camphorsulfonic acid is subsequently added and heating is carried out to reflux of the solvent. Subsequently, cooling is allowed to take place and a few drops of diisopropyl ether are added. 
     The camphorsulfonic acid salt of 2-substituted quinoline thus obtained is obtained in the form of homogeneous crystals from white to slightly beige in color. If desired, the product of formula (I), once crystallized, can be ground and/or sieved and/or granulated in combination with excipients, for example by the dry route by a compacting stage, in order to be provided in the form of a powder which is perfectly homogeneous for the purpose of the formulation thereof. 
     The physical properties of the salt of formula (I) make possible its pharmaceutical formulation in a solid formulation form of hard gelatin capsule or tablet type or also in the form of powders, in particular for reconstitution at the time of use of a solution or suspension with a uniform and reproducible composition. The crystalline form of a salt of formula (I) thus obtained is stable on storage, even under high temperature and humidity conditions, such as those of tropical climates. 
     A further subject matter of the invention is any pharmaceutical composition comprising this salt of formula (I), in particular in its crystalline form or in one of its crystalline forms, and a pharmaceutical vehicle, in particular with one or more nontoxic inert excipients suited to the pathology, to the population to be treated and to the climatic conditions. 
     Mention may be made, among the pharmaceutical compositions which can be produced from the salts of formula (I) which are subject matters of the invention, of those which make possible oral, parenteral or nasal administration, tablets (simple or sugar-coated), sublingual tablets, hard gelatin capsules, tablets, suppositories, creams, ointments, injectable preparations, suspensions to be taken orally, and the like. 
     The dosage is adjusted according to the pathology to be treated, the severity of the condition, the age and weight of the patient and the administration route. It can vary from 0.01 to 50 mg per day in one or more administrations. 
     Another subject matter of the invention is a molecule of formula (I) for the use thereof in the prevention or treatment of a disease selected from infections due to protozoa and infections due to retroviruses, in particular a disease selected from HIV, HTLV, leishmaniosis, trypanosomiasis or toxoplasmosis. 
     Another subject matter of the invention is the use of a salt of formula (I) in the preparation of a medicament intended for the prevention or treatment of a disease selected from infections due to protozoa, such as leishmaniosis, trypanosomiasis or toxoplasmosis, and/or infections due to retroviruses, such as, for example, HIV or HTLV. 
     Experimental Part 
     1—Preparation of the camphorsulfonic salt of 2-(n-propyl) quinoline 
     The 2-(n-propyl)quinoline was prepared in accordance with the procedure taught by WO 93/07125. 
     The 2-(n-propyl)quinoline thus obtained (6.5152 g) is in the form of an oil. It is dissolved in 20 ml of methanol and 60 ml of ether at 20° C. 8.8 g of camphorsulfonic acid are then added to the solution with stirring and gentle heating is carried out with stirring. 
     Cooling is allowed to take place and a few drops of diisopropyl ether are added, and the precipitation of crystals is observed, which crystals are filtered off and washed with diisopropyl ether. 
     2—Characterization 
     The crystals thus obtained (12.7439 g) are characterized by optical microscopy and by X-ray diffraction. 
     A—Optical Microscopy 
     Crystals of 2-(n-propyl)quinoline camsylate are observed in  FIG. 1 . It concerns optical microscopy photographs of crystals of camsylate salt in reflected light, magnification×40. 
     Crystals of 2-(n-propyl)quinoline camsylate are observed in  FIG. 2 . It concerns optical microscopy photographs of crystals of camsylate salt in polarized light, magnification×81. 
     B—X-Ray Diffraction 
     Equipment and Method 
     The analysis is carried out on a Bruker AXS diffractometer, model D8 Advance, in theta-theta configuration, equipped with a copper anticathode, with a sample holder made of monocrystalline silicon and with a linear detector having spatial localization. 
     First, the samples are deposited on the silicon support without prior treatment or trituration and the diffractograms are recorded according to the conditions presented in table 1. 
                                                                                                                         TABLE 1               Instrumental operating conditions for the acquisition       of the X-ray diffraction profiles                                    Temperature   Ambient           Atmosphere   Ambient                X-ray   voltage (kV)   40           generator   strength (mA)   40           X-ray source   target   Cu                emission line:   Kλ 1  (nm)   0.15406               Kλ 2  (nm)   0.15444               ratio Kλ 2 :Kλ 1     0.5                    Kβ line filter   Ni           Slit (mm)   antidivergence   0.6           Goniometer   angular sector scanned (° in 2θ)   4-70               displacement step (° in 2θ)   0.069                Rotational speed of the sample holder (rpm)   30                Detection   angular aperture (°)   8               exposure time per goniometer   6               step (s)                    
Results
 
     The experiment is carried out on four separate batches of product numbered 1 to 4. The superimposition of the X-ray diffraction profiles of the four batches is represented in  FIG. 3 . Diffraction lines are present in each of the diffractograms of the batches analyzed, indicating the presence of crystallized material, and no amorphous phase is detected. The presence of the same crystalline phase is found in the four batches. 
     The powder X-ray diffraction profile of the camsylate salt of one of the batches is illustrated in a more detailed fashion in  FIG. 5 . The profile corresponds to table 2 below, in which the list of the powder X-ray diffraction peaks of the camsylate salt is summarized. 
                                                                 TABLE 2                   List of the powder X-ray diffraction peaks of       the camsylate salt of 2-(n-propyl)quinoline                    Interlattice                   2-Theta   distance d   Intensity   Relative           angle (°)   (angstrom)   (Cts)   intensity (%)                        4.463   19.78297   2063   79.1           7.513   11.75803   196   7.5           8.64   10.22599   151   5.8           10.352   8.53876   241   9.3           11.808   7.48837   326   12.5           12.164   7.27052   917   35.1           12.975   6.81756   2329   89.3           14.223   6.22226   1295   49.6           14.407   6.14309   2609   100           15.548   5.69468   445   17           15.899   5.5697   276   10.6           17.02   5.20542   1479   56.7           17.452   5.07755   769   29.5           18.151   4.88352   489   18.8           19.247   4.60779   812   31.1           20.354   4.35972   242   9.3           20.697   4.28815   842   32.3           21.604   4.11004   234   9           22.586   3.93359   1864   71.4           22.885   3.88283   886   34           23.168   3.83615   262   10.1           23.66   3.75743   1152   44.2           24.592   3.6171   591   22.7           24.707   3.6005   641   24.6           25.298   3.5177   353   13.5           26.218   3.39633   170   6.5           26.631   3.34457   467   17.9           26.978   3.30231   982   37.6           27.217   3.27392   796   30.5           27.697   3.21819   478   18.3           28.55   3.12402   743   28.5           28.994   3.07712   268   10.3           30.352   2.94248   168   6.4           31.079   2.87526   226   8.7           31.894   2.80364   416   15.9           32.397   2.76125   155   6           33.07   2.7066   389   14.9           34.3   2.61232   184   7.1           34.607   2.58981   181   7           35.041   2.55872   198   7.6           35.809   2.5056   161   6.2           37.751   2.38103   239   9.2           38.388   2.34298   225   8.6           39.063   2.30406   144   5.5           39.54   2.27734   145   5.5           40.521   2.22446   110   4.2           41.294   2.18455   489   18.7           42.282   2.13578   121   4.6           42.604   2.1204   119   4.6           43.112   2.09658   106   4.1           44.276   2.04412   135   5.2           44.945   2.01525   136   5.2           46.119   1.96664   130   5           46.789   1.94   120   4.6           48.358   1.88066   87   3.3           48.893   1.86132   105   4           51.81   1.76319   93.7   3.6           56.362   1.6311   81.4   3.1           58.642   1.573   80.7   3.1                    
C—Hygroscopicity
 
Equipment and Method
 
     The hygroscopicity of the 2-(n-propyl)quinoline camsylate crystals is evaluated by studying the sorption/desorption isotherm of water in the vapor phase on a device of DVS-1000 type sold by SMS. 
     The sample, analyzed in a quartz pan with a specimen size of the order of 10 mg, is subjected to two cycles of variation in relative humidity (RH) which are linked together continuously. Each cycle comprises two stages, adsorption and then desorption of water, during which the relative humidity in the measuring chamber is increased and then decreased gradually according to the conditions described in table 2. 
     The sample is first dried under a stream of filtered dry air until its weight has stabilized. The stages of adsorption and of desorption are then made successively. The carrier gas used to maintain the relative humidity at a set percentage is air dried upstream of the device and delivered at a flow rate of 100 ml/min. During the progression of the program, the temperature in the measuring chamber is maintained at 25° C. 
     Results 
     The isotherms for adsorption and for desorption of water at 25° C. are represented in  FIG. 4 . 
     This sorption/desorption isotherm, carried out at 25° C., shows an increase in weight of less than 2% at 25° C./60% relative humidity, in comparison with the weight of the product equilibrated at 0% relative humidity at 25° C. 
     D—Chemical Stability 
     Preparation and Preservation of the Solutions 
     The quinoline salts are dissolved at a concentration of 200 μg/ml in five different solvents: methanol, an aqueous solution buffered at pH 7, an aqueous camphorsulfonic acid solution at pH 2, dimethyl sulfoxide (DMSO) and an aqueous solution comprising a mixture of carboxymethylcellulose at 0.5% and Tween 80 at 0.5%. 
     Each preparation is divided into three parts which are stored under different conditions of temperature and of luminosity: at 4° C., at ambient temperature under the influence of light and at ambient temperature with the exclusion of light. The samples are diluted (1:20) and then analyzed by high performance liquid chromotography (HPLC) daily for 9 days. 
     Use was made, in carrying out the high performance liquid chromotography analysis, of a Waters LC system comprising a model 600 pump with inline degassing and, as detector, a 996 photodiode detector device. The acquisition of the data was carried out by the use of the Empower® program (Waters, France). The column used was a Symmetry Shield RP18, 3.5 μm 4.6×150 mm. The isocratic mobile phase was used to determine the percentage of the quinolines with, as solvent, a mixture of solution, buffered at pH 4, of acetate and of methanol (40/60 v/v); a flow rate of 1 ml/min at 35° C. was used for the elution. The UV absorbance spectra were recorded at between 210 and 400 nm. The chromatogram of the propyl salt was recorded at 233 nm and that of the alcohol derivative at 249 nm. 
     Results 
     It is found that the propyl salt is stable whatever the conditions tested. 
     The 2-(n-propyl)quinoline in the form of the camphorsulfonic acid salt exhibits a chemical stability compatible with the development of a medicament. 
     E—Acute Toxicity 
     Preparation of the Emulsions and Administration of the Quinoline Salts 
     250 mg of carboxymethylcellulose are dissolved in 50 ml of a 5% glucose solution. 5 ml aliquots containing 0.5% of Tween 80 are emulsified with the quinoline salts (final concentrations at 0.4 mg/ml, 4 mg/ml and 40 mg/ml). The emulsions are subsequently homogenized. The emulsions are administered by force feeding in a single dose to four groups of five female CD-1 mice at the concentrations of 10 mg/kg, 100 mg/kg and 1000 mg/kg and without compounds (control group). The control group receives a glucose-comprising emulsion containing 0.5% of carboxymethyl-cellulose (CMC) and 5% of Tween 80. The behavior of the animals is observed and the number of deaths is counted after 1 min, 15 min, 30 min, 1 h, 4 h, 8 h and each day for 14 days. On the final day, a blood sample is taken. Biochemical analyses are carried out in order to evaluate the nephrotoxicity and the hepatotoxicity, the levels of creatinine, of aspartate aminotransferase (ASAT), of alanine aminotransferase (ALAI) and of cholesterol being quantitatively determined. 
     Results 
     In accordance with the results appearing in tables 3 and 4, no signs of irreversible toxicity can be demonstrated at 1 g/kg. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Acute toxicity 
               
             
          
           
               
                   
                 No. of 
                 Single dose 
                   
               
               
                 Compound 
                 animals 
                 (oral route) 
               
               
                   
               
             
          
           
               
                 Camphorsulfonate 
                 5 
                 1 
                 g/kg 
                 t15 min = 3 mice showed 
               
               
                 salt of 2-(n- 
                   
                   
                   
                 signs of lethargy 
               
               
                 propyl)quinoline 
                   
                   
                   
                 t1 h = 2 lethargic mice 
               
               
                   
                   
                   
                   
                 t4 h = absence of toxicity 
               
               
                   
                   
                 100 
                 mg/kg 
                 absence of toxicity 
               
               
                   
                   
                 10 
                 mg/kg 
                 absence of toxicity 
               
               
                 Camphorsulfonate 
                 5 
                 1 
                 g/kg 
                 t15 min - 1 mouse had 
               
               
                 salt of 
                   
                   
                   
                 bristling hair 
               
               
                 2-(hydroxyprop- 
                   
                   
                   
                 t1 h - absence of toxicity 
               
               
                 2-enyl)quinoline 
                   
                 100 
                 mg/kg 
                 absence of toxicity 
               
               
                   
                   
                 10 
                 mg/kg 
                 absence of toxicity 
               
             
          
           
               
                 Control 
                   
                 CMC/Tween 
                 absence of toxicity 
               
               
                   
               
             
          
         
       
     
                                                                                                       TABLE 4                   Biochemical parameters                    Creatinine   Cholesterol   ASAT   ALAT       Compound   Dose   (μM)   (mM)   (IU/l)   (IU/l)                    Camphorsulfonate   1   g/kg   &lt;18   3.8 ± 0.4    422 ± 187   199 ± 89       salt of 2-(n-   100   mg/kg   &lt;18   4.1 ± 0.5   515 ± 72   168 ± 67       propyl)quinoline   10   mg/kg   &lt;18   3.9 ± 0.3   410 ± 57    215 ± 123       Camphorsulfonate   1   g/kg   20.7 ± 3.1   3.4 ± 0.6   388 ± 70    260 ± 131       salt of 2-   100   mg/kg   &lt;18   4.6 ± 0.5    397 ± 202   247 ± 76       (hydroxyprop-2-   10   mg/kg   &lt;18   3.9 ± 0.3   337 ± 80   223 ± 74       enyl)quinoline                                    Control   CMC/Tween   &lt;18   3.5 ± 0.5    456 ± 276   304 ± 25                    
3—Formulation
 
     A hard gelatin capsule is prepared using the following ingredients: camphorsulfonic salt of 2-(n-propyl)quinoline, lactose, hydroxypropylmethylcellulose, silica and magnesium stearate.