Succinate salts of n-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1h-benzo[d]imidazol-2-amine, preparation thereof and use of the same

Abstract

To provide novel salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, which are particularly suitable for solid formulations and obtained from robust chemical methods.SOLUTION: The present invention relates to succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to novel succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and their pharma- ceutically acceptable solvates, their preparation, pharmaceutical compositions containing them and their use in the treatment and / or prevention of neurodegenerative diseases. [Background technology]

[0002] Formula I

[0003] [ka]

[0004] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine having the structure: is a pharma- ceutically active molecule (PAM) which belongs to the family of 1,4-bis(3-aminopropyl)piperazine derivatives already disclosed in WO 2006 / 051489 and is useful for the treatment and / or prevention of neurodegenerative diseases.

[0005] The free base form of this compound presents long-term stability problems due to oxidative degradation. Therefore, the applicant has searched for a salt form that overcomes these stability problems and has discovered the sulfate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, described in WO 2014 / 102339. The sulfate salts are obtained as stable powders having a crystalline phase with good crystallinity without oxidative degradation; they are not hygroscopic based on commonly used standards (i.e., less than 2% water uptake by weight at 25° C. / 60% relative humidity (RH)). In particular, the applicant has found that N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate is stable for at least 5 years under normal storage conditions (15-25° C.) and has significant water solubility of greater than 100 mg / mL. Thus, N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sulfate is a suitable active pharmaceutical ingredient (API).

[0006] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate API has been developed for the treatment of neurodegenerative diseases and has successfully completed Phase 1 clinical trials with healthy volunteers. This disulfate API was administered orally to healthy volunteers in a liquid formulation: a solution in water. These aqueous solutions are easy to prepare and are remarkably stable (up to 18 months at 5°C, up to 18 months at 25°C / 60% RH, up to 6 months at 40°C / 75% RH in glass vials) without the need for any preservatives. The same formulation is being used in an ongoing Phase 2A clinical trial with patients suffering from Progressive Supranuclear Palsy (PSP).

[0007] The applicants wished to develop a solid formulation (e.g., capsules) of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine PAM under salt form, and the free base was excluded due to its instability issues and lower solubility. Indeed, solid formulations offer many advantages over liquid formulations: stability, packaging, supply, storage, handling and logistics are easier and more cost-effective. Unlike liquid formulations, development of solid formulations (regulatory compliance) requires the API to be in unique and well-defined polymorphic forms. Polymorphic forms or polymorphs of a molecule refer to different molecular solid states with different and unique physicochemical properties such as crystallinity, melting point, solubility and stability. The properties of the API and its solid formulations depend on the polymorphic form of the API; polymorphs may exhibit different stability, solubility, dissolution rate, which can dramatically affect the bioavailability of the drug. Therefore, drug approval and regulatory authorities require that solid dosage forms of drugs are unique and stable API polymorphs; for example, see the U.S. Food and Drug Administration Guidance for Industry on Chemistry, Manufacturing and Controls (CMC) Requirements for Abbreviated New Drug Application Submissions When Drug Substances Exist in Polymorphic Forms (Docket No. FDA-2004-D-0182). Therefore, selecting the right polymorphic form of the right salt is important for API development, and implementing a reproducible chemical method for its synthesis is equally detrimental. In this case, the final step of the API synthesis method is salt formation, which needs to be optimized to directly obtain the selected polymorphic form. In other words, the method will be more efficient and cost-effective if a salt / polymorphic form that is compatible with the one-pot salt formation-direct crystallization final step is selected.

[0008] Applicant first investigated N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate and performed a comprehensive polymorph screening, which led to the identification of many polymorphic forms. The polymorphic form designated "Form A", whose XRPD diffractogram is shown in Figure 1, was identified as the most suitable stable form and sent for preparation of solid formulations. Applicant then sought to develop a reproducible chemical method synthesis of Form A, i.e., to identify suitable conditions (solvent, anti-solvent, concentration, duration, temperature, nucleation conditions, filtration, drying conditions) for one-pot disulfate formation / direct crystallization under this polymorphic form from the free base starting material. Despite extensive research, Applicant was not able to achieve this result and was only able to obtain the desired Form A polymorphic form in two separate steps from the free base: 1) disulfate formation under the polymorphic form designated "Form B", followed by 2) conversion of Form B to the target Form A. Applicants further identified that the target Form A is sensitive to drying conditions as it converts back to polymorphic Form B when dried at 50° C. Such sensitivity further limits the process on an industrial scale and Applicants have instead investigated Form B as this form is amenable to a more efficient one-pot salt formation / crystallization final step.

[0009] Form B, whose XRPD diffractogram is disclosed in FIG. 2, is the most prominent polymorphic form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate identified from polymorph screening studies. However, there is a risk of crystal form conversion in some different solvents or under high humidity conditions, and it may have a tendency of salt disproportionation (formation of trisulfate) in alcoholic solvents. In addition, Form B partially loses its crystallinity upon long drying periods at 50° C. Therefore, the applicant has disregarded Form B as a suitable polymorphic form for developing solid dosage forms.

[0010] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate is a stable, crystalline, non-hygroscopic powder API, yet it exhibits a complex polymorphic landscape with respect to crystal form stability and synthetic process efficiency. A robust and cost-effective synthetic process with a one-pot salt formation / direct crystallization final step cannot be assumed to guarantee the acquisition of a specific stable polymorphic form. The polymorphs of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine that passed the polymorph screening criteria were unstable to boot with conventional drying at 50° C., leading the Applicant to conclude that the disulfate salt may not be suitable for obtaining solid formulations of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine PAM.

[0011] WO 2014 / 102339 discusses other salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine. The oxalate salt originally reported in WO 2006 / 051489 is not suitable due to the nephrotoxicity that the oxalate ion can cause. The hydrochloride salt turned out to be straightforwardly very hygroscopic, while the acetate salt was not obtained in solid form. The tartrate and fumarate salts were obtained as amorphous solids. The malate salt was abandoned due to its chirality, which considerably complicates clinical development, since each stereoisomer needs to be equally characterized as the active stereoisomer. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] WO 2006 / 051489 [Patent Document 2] WO 2014 / 102339 [Non-patent literature]

[0013] [Non-Patent Document 1] Brain J. Neurol., Vol. 140, pp. 3081 - 3104 (2017) [Non-Patent Document 2] Trends Neurosci., Vol. 37, pp. 388 - 398 (2014) [Non-Patent Document 3] J. Reprod. Dev., Vol. 57, pp. 113 - 119 (2011) [Non-Patent Document 4] Acta Neuropathol. (Berl.), Vol. 119, pp. 123 - 133 (2010) [Non-Patent Document 5] Neuroscience, Vol. 250, pp. 8 - 19 (2013) [Non-Patent Document 6] J. Neuropathol. Exp. Neurol., Vol. 74, pp. 158 - 165 (2015) [Non-Patent Document 7] Neurology, Vol. 90, pp. 118 - 125 (2018) [Non-Patent Document 8] J. Neuroinflammation, Vol. 7, 56 (2010) [Non-Patent Document 9] PLOS one 2014, 9, 5, e97032 [Non-Patent Document 10] Neuroscience Letters, Vol. 725, April 23, 2020, 134873 [Non-Patent Document 11] Remington's Pharmaceutical Sciences [Non-Patent Document 12] Gordon, A. J.; Ford, R. A. 「The Chemist's Companion - A Handbook of Practical Data, Techniques, and References」, Wiley: New York, 1972 [Non-Patent Document 13] Vogel's Textbook of Practical Organic Chemistry, Pearson Prentice Hall: London, 1989 [Non-Patent Document 14] P. Heinrich Stahl and Camille G. Wernuth "Handbook of Pharmaceutical Salts", Wiley VCH [Non-Patent Document 15] Callizot et al., J Neurosci Res. 2013, 91:706-716 [Non-Patent Document 16] Visanji et al., FASEB J. 2008, vol. 22(no. 7): 2488-2497 [Non-Patent Document 17] Callizot et al., PlosOne 2019: https: / / doi.org / 10.1371 / journal.pone.0215277 Summary of the Invention [Problem to be solved by the invention]

[0014] Thus, there remains a need in the art for stable polymorphic forms of novel salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, which are particularly suitable for solid dosage forms and are obtained from robust chemical methods. [Means for solving the problem]

[0015] The present invention is based on the unexpected finding that the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine provides a stable powder, the polymorph of which is highly crystalline, very stable, non-hygroscopic and can be obtained in good yields in one-pot salt formation / direct crystallization from the free base. The succinate salt meets the stringent requirements mentioned above and is particularly suitable for use as an API in solid dosage forms such as capsules.

[0016] Thus, the present invention relates to the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and pharma- ceutically acceptable solvates thereof.

[0017] The succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and their solvates are obtained as powders having a crystalline phase with a high degree of crystallinity and well-defined morphology. The succinate salts of the present invention are further particularly suitable for the preparation of pharmaceutical compositions containing them. The succinate salts are pharma- ceutically acceptable and, to the best of the applicant's knowledge, are not associated with any inherent toxicity of any kind.

[0018] Furthermore, when compared to other salts, such as the sulfate salt, the succinate salt has a simpler polymorphic situation, the polymorphic forms are more crystalline, more stable (i.e., no change in crystal form) during the synthesis process, especially to conventional drying at 50° C., and do not undergo disproportionation (i.e., stoichiometry change) in the solvents used in the process.

[0019] The use of the succinate salt will enhance and facilitate the manufacture of pharmaceutical compositions containing N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine PAM while resulting in reduced associated costs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The compound of the present invention is the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and its pharma- ceutically acceptable solvates. More particularly, the succinate salt and its solvates of the present invention are represented by the formula II

[0021] [ka]

[0022] [wherein x is 1 to 4, preferably x is 1.4 to 3.1, more preferably x is 1.4 to 1.6, even more preferably x is about 1.5, and even more preferably x is 1.5] It is of the following.

[0023] In other words, the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine contains 1 to 4 equivalents, preferably 1.4 to 3.1 equivalents, more preferably 1.4 to 1.6 equivalents, even more preferably about 1.5 equivalents, and even more preferably 1.5 equivalents of the succinate salt per molecule of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine.

[0024] In a preferred embodiment, the succinate salt of the present invention is the sesquisuccinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine.

[0025] In one embodiment, a preferred succinate salt of the invention is a compound of formula II, wherein x is between 2.9 and 3.1, preferably, x is about 3, and more preferably, x is 3.

[0026] In another preferred embodiment, the succinate salt of the present invention is the trisuccinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine.

[0027] In certain embodiments, the succinate salt of formula II is in the form of a pharma- ceutically acceptable solvate, preferably a hydrate, with a solvate stoichiometry of 0.4-2, preferably 0.4-1.2, more preferably 0.5-1.1, even more preferably about 0.5 or about 1.1, even more preferably 0.5 or 1.1 molecules of solvate per molecule of succinate salt of formula II.

[0028] In one embodiment, the compound of the invention is N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt hemihydrate.

[0029] In another embodiment, the compound of the invention is N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt monohydrate.

[0030] The applicant has identified several polymorphic forms of the compound of the present invention that are particularly stable against 1) chemical degradation, such as salt disproportionation, and 2) polymorphic change. These polymorphs have a high degree of crystallinity, are stable under normal storage and stress conditions, and are not hygroscopic. The applicant has found experimental conditions for the specific preparation of these polymorphic forms using a one-pot salt formation / crystallization final step from the free base. Thus, the compound of the present invention is useful as an API for use in solid dosage forms.

[0031] In one embodiment, one particularly preferred compound of the present invention is a compound of formula II, where x is 1.5, in a crystalline form having an X-ray powder diffraction (XRPD) pattern comprising peaks at diffraction angles 2θ=3.8°±0.2°, 10.3°±0.2°, 12.4°±0.2°, 16.2°±0.2°, 17.9°±0.2°, 19.8°±0.2°, 20.4°±0.2°, 23.8°±0.2°, and 26.7°±0.2° when irradiated with a CuKα source. This particular crystalline form is referred to throughout the specification as "Form 1" and its XRPD diffractogram, recorded on a PANalytical X'pert pro equipped with a PIXcel detector (128 channel), is shown in FIG. 3.

[0032] Another preferred compound of the present invention is the compound of formula II, where x is 3, under the crystalline form having an X-ray powder diffraction (XRPD) pattern comprising peaks at diffraction angles 2θ=5.3°±0.2°, 15.0°±0.2°, 15.3°±0.2°, 16.8°±0.2°, 17.9°±0.2°, 20.5°±0.2°, 21.2°±0.2°, 23.9°±0.2°, 24.3°±0.2° and 26.6°±0.2° when irradiated with a CuKα source. This particular crystalline form is referred to throughout the specification as "Form 2" and its XRPD diffractogram recorded on a PANalytical X'pert pro equipped with a PIXcel detector (128 channel) is shown in FIG. 4.

[0033] Another preferred compound of the present invention is the compound of formula II, in which x is 1.5, y is 0.5, and in crystalline form, having an X-ray powder diffraction (XRPD) pattern with peaks at diffraction angles 2θ=3.8°±0.2°, 4.4°±0.2°, 9.2°±0.2°, 10.6°±0.2°, 13.8°±0.2°, 17.7°±0.2°, 19.9°±0.2°, 21.6°±0.2°, and 23.6°±0.2° when irradiated with a CuKα source. Its XRPD diffractogram, recorded on a PANalytical X'pert pro equipped with a PIXcel detector (128 channel), is shown in FIG. 5.

[0034] Another preferred compound of the present invention is the compound of formula II, in which x is 1.5 and y is 1.1, and in crystalline form, having an X-ray powder diffraction (XRPD) pattern including peaks at diffraction angles 2θ=4.2±0.2°, 4.4°±0.2°, 9.6°±0.2°, 10.6°±0.2°, 15.0°±0.2°, 16.3°±0.2°, 17.4°±0.2°, 19.7°±0.2°, 22.8°±0.2°, 29.1° and 29.7°±0.2° when irradiated with a CuKα source. Its XRPD diffractogram, recorded on a PANalytical X'pert pro equipped with a PIXcel detector (128 channel), is shown in FIG. 6.

[0035] The crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate can be obtained by chemical synthesis methods. Another object of the present invention is such a method.

[0036] The present invention also provides a method for making a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, comprising the steps of: - Step 1: N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine is dissolved in an organic solvent; - step 2: heating the reaction medium to temperature B, where temperature B is defined as a temperature comprised between 30 and 50°C; - step 3: adding a substantially equimolar amount of succinic acid; - step 4: the reaction medium is stirred at temperature B for 0.25 to 4 hours; step 5: temperature A is defined as a temperature comprised between 0 and 10° C., and the reaction medium is subjected to a temperature cycle from temperature A to temperature B in cycles of 2 to 4 hours over a period of 10 to 30 hours; - step 6: the reaction medium is cooled to a temperature A; - step 7: filtering the reaction medium at temperature A; - step 8: washing the filter cake with said organic solvent at temperature A; - Step 9: Dry the filter cake at a temperature of 30-50°C. The present invention relates to a method comprising the steps of:

[0037] In a first step, a solution of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine is obtained. The N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine starting material useful for making the solution can be of purity ≧95% and any physical form of the free base, including solvated forms. In one embodiment, the organic solvent is selected from the group consisting of acetone, 97.5% acetone / 2.5% water (% v / v), methyl ethyl ketone, acetonitrile, tert-butyl methyl ether. In a particularly preferred embodiment, the organic solvent used is methyl ethyl ketone, which is particularly suitable for preparing crystalline form 1. The volume of organic solvent used is important to achieve dissolution of the free base and to allow its successful salt formation and crystallization. In a preferred embodiment, the amount of organic solvent added is 20-40 mL per gram of free base, preferably 25-35 mL per gram of free base, and more preferably about 30 mL per gram of free base.

[0038] In a preferred embodiment, the heating step 2 is carried out at a temperature B comprised between 35 and 45°C, more preferably between 40 and 45°C, even more preferably at a temperature of about 40°C, even more preferably at 40°C.

[0039] An optional filtration step at temperature B can be realized between step 2 and the subsequent succinic acid addition step 3. The succinic acid is added in a substantially equimolar amount relative to the N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine free base. In other words, 0.95 to 1.05 equivalents (eq.) relative to the succinic acid free base are added. In a preferred embodiment, 1.0 equivalent of succinic acid is used.

[0040] In step 3, the succinic acid addition is carried out in small portions using succinic acid in powder form or by slowly adding a suspension or solution of concentrated succinic acid in the organic solvent used to dissolve the base. In a preferred embodiment, the succinic acid is added in powder form. In another preferred embodiment, the succinic acid is added as a concentrated solution in an organic solvent.

[0041] In step 4, the reaction medium is then stirred at temperature B for 0.5 to 4 hours during which the salt formation begins. In a preferred embodiment, the medium is stirred for 20 to 40 minutes, preferably about 30 minutes. In another preferred embodiment, the medium is stirred for 2 to 4 hours, preferably about 3 hours.

[0042] The subsequent temperature cycling step 5 allows the sesquisuccinate to crystallize under a particular crystal form. The temperature cycling is carried out at temperature A to temperature B in 2-4 hour cycles over a period of 10-30 hours, where temperature A is defined as a temperature comprised between 0 and 10°C. In a particularly preferred embodiment, the temperature cycling is carried out at about 5°C to about 40°C in about 3 hour cycles over a period of about 20 hours, thereby allowing the sesquisuccinate to crystallize under crystal form 1, especially when methyl ethyl ketone is used as the organic solvent.

[0043] At this point, a crystalline salt usually precipitates out, and the reaction medium is cooled to a temperature comprised between 0 and 10°C, preferably about 5°C (step 6), and then the desired material is recovered by filtration at the same temperature (step 7). The desired crystalline salt is recovered in a filter cake, which is washed once with the same organic solvent used in the reaction (step 8). In a preferred embodiment, a volume of about 5 mL of organic solvent per gram of material is used in the filter cake wash.

[0044] The filtered and washed material is then dried (step 9), preferably under reduced pressure, at a temperature between 30 and 50° C., preferably around 40° C.

[0045] A particularly preferred process according to the invention by which N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate Form 1 can be obtained is the following: - step 1: dissolving N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine in methyl ethyl ketone; - step 2: the reaction medium is heated to 45°C; - step 3: adding an equimolar amount of succinic acid; - step 4: the reaction medium is stirred at 45°C for 3-4 hours; - step 5: the reaction medium is temperature cycled from 5°C to 40°C in 3 hour cycles over a period of 20 hours; - step 6: the reaction medium is cooled to 5°C; - step 7: filtering the reaction medium at 5°C; - step 8: washing the filter cake with said organic solvent at 5°C; - Step 9: The filter cake is dried under vacuum at 40°C.

[0046] The process according to the invention allows for the direct one-pot salt formation / crystallization of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate.

[0047] When adapted by 1) using ethanol as the organic solvent and 2) changing the stoichiometry of succinic acid in step 3 to about 2 equivalents, the method according to the invention allows the direct one-pot salt formation / crystallization of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate.

[0048] The applicant has shown that succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and their pharma- ceutically acceptable solvates are useful for modifying the metabolism of tau protein, in particular by inhibiting pathological tau protein phosphorylation. Tau protein (also known as microtubule-associated protein tau-MAPT) interacts with tubulin to stabilize microtubules and promotes the assembly of tubulin into microtubules, with microtubule stability being controlled by isoforms and phosphorylation. Tau pathology involves abnormal modifications of microtubule-associated tau protein, such as its hyperphosphorylation, leading to its progressive aggregation and accumulation into fibrillar material inside degenerating neurons, a mechanism that forms so-called neurofibrillary tangles (NFTs). The compounds of the invention are efficient in preserving the neurite network of neurons and promoting neurite outgrowth. Neurites are projections from the cell body of neurons, and their preservation and growth are detrimental to interneuronal connections. Furthermore, the compounds of the present invention can reduce neuroinflammation and microglial activation while increasing the levels of progranulin (PGRN) neurotrophic factor. Neuroinflammation is a secondary response in chronic progressive neurodegenerative diseases, including but not limited to tauopathies and Parkinson's disease, which can be caused by activated microglial cells releasing neurotoxic proinflammatory cytokines that contribute to neuronal loss. PGRN is a secreted glycoprotein expressed primarily in mature neurons and microglia that maintains cerebral cortical viability (Brain J. Neurol. 140, 3081-3104 (2017)). PGRN expression in the brain is low in early development and increases with age (Trends Neurosci. 37, 388-398 (2014), J. Reprod. Dev. 57, 113-119 (2011)). However, in response to injury, activated microglia upregulate PGRN expression (Acta Neuropathol. (Berl.) 119:123-133 (2010); Neuroscience 250:8-19 (2013)).With regard to tau pathology, PGRN deficiency accelerates tau deposition and phosphorylation in human tau-expressing mice (J. Neuropathol. Exp. Neurol. 74, 158-165 (2015)). PGRN can be processed into granulin by several proteases, including elastase, released from activated microglia (Neurology 90, 118-125 (2018)). Human and rodent data show that PGRN reduction is associated with increased tau pathology. PGRN haploinsufficiency increases tau phosphorylation in P301L-tau transgenic mice, strongly supporting the idea that reduction of PGRN protein may contribute to tau hyperphosphorylation and interneuronal accumulation (J. Neuropathol. Exp. Neurol. 74, 158-165 (2015)). In addition, inflammatory stimuli in the brain have also been reported to be associated with worsening tau phosphorylation (J. Neuroinflammation Vol. 7, 56 (2010)). As PGRN may act as an anti-inflammatory factor in neuroinflammation (Neuroscience Vol. 250, pp. 8-19 (2013)), it is hypothesized that tau phosphorylation is accelerated in inflammatory conditions resulting from reduced PGRN levels. PGRN is a neurotrophic factor whose role in Parkinson's disease has been well investigated. Van Kampen et al. have investigated the possibility of using PGRN gene delivery as a therapy for the prevention or treatment of PD using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD (PLOS one 2014, 9, 5, e97032). Viral vector delivery of the PGRN gene was an effective means of elevating PGRN expression in nigrostriatal neurons. PGRN expression in the SN. CWhen elevated in mice, nigrostriatal neurons are protected from MPTP toxicity in mice with preservation of striatal dopamine content and turnover. Furthermore, protection of nigrostriatal neurons by PGRN gene therapy was accompanied by reduction of markers of MPTP-induced inflammation and apoptosis, and complete preservation of motor function. Furthermore, blood levels of progranulin may reflect the severity and progression of Parkinson's disease in humans (Neuroscience Letters Vol. 725, April 23, 2020, 134873). Progranulin plasma levels were found to be significantly lower in Parkinson's disease patients compared to controls, and also negatively correlated with motor symptoms, disease severity and duration, thus suggesting a neuroprotective effect of PGRN in PD. All these findings support that increasing PGRN levels may be an effective treatment for improving neurodegenerative diseases such as tauopathy and Parkinson's disease. In particular, the succinate salt of the present invention is neuroprotective and inhibits the mitochondrial toxin MPTP. + or rotenone; were found to be able to significantly reduce α-synuclein aggregation in damaged dopaminergic neurons in two well-known in vitro models of PD.

[0049] Tauopathies include, but are not limited to, Alzheimer's disease, amyotrophic lateral sclerosis and parkinsonism-dementia complex of Guam, argyrophilic granule disease, chronic traumatic encephalopathy, corticobasal degeneration, dementia pugilistica, diffuse neurofibrillary tangle disease with calcifications, familial British dementia, familial Danish dementia, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Gerstmann-Sträussler-Scheinker disease, Guadeloupe-type parkinsonism, These include: Hallervorden-Spatz disease, inclusion body myositis, multiple system atrophy, Steinert myotonic dystrophy, myotonic dystrophy type II, neurodegeneration with brain iron accumulation, Niemann-Pick disease type C, non-Guam motor neuron disease with neurofibrillary tangles, Paget's disease, Pick's disease, postencephalitic parkinsonism, progressive subcortical gliosis, progressive supranuclear palsy (PSP), SLC9A6-associated mental retardation, subacute sclerosing panencephalitis, dementia with neurofibrillary tangles, multi-infarct dementia, ischemic stroke, chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), stroke, and white matter tauopathy with globular glial inclusions.

[0050] In addition, the physicochemical properties, such as crystallinity, stability, solubility, of the succinate salts of the present invention and their solvates are particularly useful for solid and liquid drug formulations.

[0051] Thus, as described above, due to their ability to modify the metabolism of tau protein, increase the levels of PGRN neurotrophic factor, and reduce neuroinflammation, the succinate salts and solvates thereof of the present invention are useful as pharmaceuticals for treating or preventing neurodegenerative diseases, including, inter alia, tauopathies and Parkinson's disease.

[0052] The succinate salt of the present invention is therefore useful as a medicament for treating or preventing neurodegenerative diseases, including, but not limited to, tauopathies, and all diseases in which a dysfunction of tau protein phosphorylation is observed.

[0053] In one embodiment, the present invention relates to a succinate salt of the invention for use in the treatment or prevention of a disease selected from neurodegenerative diseases, including but not limited to tauopathies, and diseases in which dysfunction of tau protein phosphorylation is observed.

[0054] Thus, the present invention also relates to the treatment of Alzheimer's disease, amyotrophic lateral sclerosis of Guam and parkinsonism-dementia complex, argyrophilic granule disease, chronic traumatic encephalopathy, corticobasal degeneration, dementia pugilistica, diffuse neurofibrillary tangle disease with calcifications, familial British dementia, familial Danish dementia, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Gerstmann-Sträussler-Scheinker disease, Guadeloupe-type parkinsonism, Hallervorden-Spatz disease, inclusion body myositis, multiple system atrophy, Steinert myotonic dystrophy, myotonic dystrophy type II, brain iron accumulation and / or a medicament for the treatment and / or prevention of a disease selected from neurodegeneration associated with glaucoma, Niemann-Pick disease type C, non-Guam motor neuron disease with neurofibrillary tangles, Paget's disease, Pick's disease, postencephalitic parkinsonism, progressive subcortical gliosis, progressive supranuclear palsy (PSP), SLC9A6-associated mental retardation, subacute sclerosing panencephalitis, dementia with neurofibrillary tangles, multi-infarct dementia, ischemic stroke, chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), stroke, and leukotauopathy with globular glial inclusions. Preferably, the disease is selected from Alzheimer's disease, argyrophilic granule disease, corticobasal degeneration, diffuse neurofibrillary tangle disease with calcifications, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Pick's disease, progressive subcortical gliosis, progressive supranuclear palsy (PSP), dementia with neurofibrillary tangles, and white matter tauopathy with globular glial inclusions.More preferably, the disease is selected from Alzheimer's disease, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), progressive supranuclear palsy (PSP), dementia with neurofibrillary tangles, and leukotauopathy with globular glial inclusions. Even more preferably, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0055] In other words, the present invention also provides a method for treating and / or preventing tauopathies, in particular diseases selected from those listed above and specific examples thereof, comprising administering to a patient in need thereof a pharma- ceutical effective amount of the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine as described herein or a pharma- ceutical acceptable solvate thereof. In certain embodiments, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0056] In other words, the present invention also provides the use of the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or a pharma- ceutically acceptable solvate thereof as described herein in the manufacture of a medicament for treating and / or preventing a tauopathy, in particular a disease selected from those listed above and specific examples thereof. In certain embodiments, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0057] In another embodiment, the present invention also relates to a succinate salt of the present invention for use in delaying in a patient the onset of a disease selected from neurodegenerative diseases, including but not limited to tauopathies, and diseases in which dysfunction of tau protein phosphorylation is observed.

[0058] In a particular embodiment, the present invention also relates to a method for treating Alzheimer's disease, amyotrophic lateral sclerosis of Guam and parkinsonism-dementia complex, argyrophilic granule disease, chronic traumatic encephalopathy, corticobasal degeneration, dementia pugilistica, diffuse neurofibrillary tangle disease with calcifications, familial British dementia, familial Danish dementia, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Gerstmann-Sträussler-Scheinker disease, Guadeloupe-type parkinsonism, Hallervorden-Spatz disease, inclusion body myositis, multiple system atrophy, Steinert myotonic dystrophy, myotonic dystrophy type II, brain iron tauopathy with neurodegeneration, neurodegeneration with neurofibrillary tangles, Niemann-Pick disease type C, non-Guam motor neuron disease with neurofibrillary tangles, Paget's disease, Pick's disease, postencephalitic parkinsonism, progressive subcortical gliosis, progressive supranuclear palsy (PSP), SLC9A6-associated mental retardation, subacute sclerosing panencephalitis, dementia with neurofibrillary tangles, multi-infarct dementia, ischemic stroke, chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), stroke, and leukopathies with globular glial inclusions. Preferably, the disease is selected from Alzheimer's disease, argyrophilic granule disease, corticobasal degeneration, diffuse neurofibrillary tangle disease with calcifications, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Pick's disease, progressive subcortical gliosis, progressive supranuclear palsy (PSP), dementia with neurofibrillary tangles, and white matter tauopathy with globular glial inclusions.More preferably, the disease is selected from Alzheimer's disease, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), progressive supranuclear palsy (PSP), dementia with neurofibrillary tangles, and leukotauopathy with globular glial inclusions. Even more preferably, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0059] In other words, the present invention provides a method for delaying the onset of a tauopathy, in particular a disease selected from those listed above and specific examples thereof, in a patient, comprising administering to a patient in need thereof a pharma- ceutical effective amount of the succinate salt of the present invention or a pharma- ceutical acceptable solvate thereof. In a particular embodiment, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0060] In other words, the present invention also provides the use of a succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, or a pharma- ceutically acceptable solvate thereof, as described herein, in the manufacture of a medicament for delaying the onset of a tauopathy, in particular a disease selected from those listed above and specific examples thereof, in a patient. In certain embodiments, the disease is selected from Alzheimer's disease and progressive supranuclear palsy (PSP).

[0061] The present invention also relates to the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine as defined herein or a pharma- ceutically acceptable solvate thereof for use in treating and / or preventing Parkinson's disease.

[0062] In other words, the present invention also provides a method of treating and / or preventing Parkinson's disease, comprising the step of administering to a patient in need thereof a pharma- ceutical effective amount of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, succinate salt or a pharma- ceutically acceptable solvate thereof, as described herein.

[0063] In other words, the present invention also provides the use of a succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, or a pharma- ceutically acceptable solvate thereof, as described herein, in the manufacture of a medicament for treating and / or preventing Parkinson's disease.

[0064] In a particular embodiment, the invention also relates to the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, as defined herein, or a pharma- ceutically acceptable solvate thereof, for use in delaying the onset of Parkinson's disease in a patient.

[0065] In other words, the present invention provides a method for delaying the onset of Parkinson's disease in a patient, comprising the step of administering to a patient in need thereof a pharma- ceutical effective amount of the succinate salt of the present invention, or a pharma- ceutical acceptable solvate thereof.

[0066] In other words, the present invention also provides the use of a succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, or a pharma- ceutically acceptable solvate thereof, as described herein, in the manufacture of a medicament for delaying the onset of Parkinson's disease in a patient.

[0067] According to a further feature of the present invention there is provided a method for inhibiting pathological tau protein phosphorylation in a patient, preferably a warm-blooded animal, even more preferably a human, in need of such treatment, comprising the step of administering to said patient an effective amount of the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine of the present invention, or a pharma- ceutically acceptable solvate thereof.

[0068] According to yet a further feature of the present invention there is provided a method for inhibiting pathological tau protein phosphorylation whilst increasing the level of the neurotrophic factor progranulin (PGRN) in a patient, preferably a warm-blooded animal, even more preferably a human, in need of such treatment, comprising the step of administering to said patient an effective amount of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine succinate salt or a pharma- ceutically acceptable solvate thereof according to the present invention.

[0069] The present invention also provides a pharmaceutical composition comprising the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or a pharma- ceutically acceptable solvate thereof as described herein and at least one pharma- ceutically acceptable carrier, diluent, excipient and / or adjuvant. In one embodiment, the present invention also includes a pharmaceutical composition containing, in addition to the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or a pharma- ceutically acceptable solvate thereof as the active ingredient, an additional therapeutic agent and / or active ingredient.

[0070] According to one embodiment, the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine of the present invention, and its pharma- ceutically acceptable solvates, may be administered as part of a combination therapy. Thus, within the scope of the present invention are embodiments that include co-administration of compositions and medicaments containing additional therapeutic agents and / or active ingredients in addition to the succinate salt of the present invention or its pharma- ceutically acceptable solvates as the active ingredient. Such multi-drug regimens are often referred to as "combination therapy" and may be used in the treatment and / or prevention of any neurodegenerative disease, particularly tauopathies or Parkinson's disease. The use of such combinations of therapeutic agents is particularly appropriate for the treatment of the above-mentioned neurodegenerative diseases in patients in need of treatment or at risk of becoming such patients.

[0071] In addition to the requirement of therapeutic efficacy that may require the use of an active ingredient in addition to the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or a pharmaceutically acceptable solvate thereof, there may be additional rationales that mandate or strongly recommend the use of a drug combination with an active ingredient that corresponds to an adjunct therapy, i.e. an adjunct therapy that complements and supplements the function performed by the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or a pharmaceutically acceptable solvate thereof of the present invention. Suitable adjunctive therapeutic agents used for the purpose of adjunctive treatment include drugs that, instead of directly treating and / or preventing a disease or condition mediated or associated with pathological protein tau phosphorylation and / or neuroinflammation, treat a disease or condition that results directly from or is indirectly associated with an underlying disease or condition that is regulated by pathological protein tau phosphorylation and / or neuroinflammation.

[0072] According to a further feature of the invention, the succinate salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, a pharma- ceutically acceptable solvate thereof, may be used in combination therapy with other drugs used to treat neurodegenerative diseases, such as Alzheimer's disease, Progressive Supranuclear Palsy (PSP) and Parkinson's disease. More particularly, the compound of formula II, and pharma- ceutically acceptable solvates thereof, may be used in combination with acetylcholinesterase inhibitors, including but not limited to, donepezil (CAS No. 120014-06-4) and salts and solvates thereof, galantamine (CAS No. 357-70-0) and salts and solvates thereof, rivastigmine (CAS No. 123441-03-2) and salts and solvates thereof, tacrine (CAS No. 321-64-2) and salts and solvates thereof, or in combination with NMDA glutamate receptor antagonists, including but not limited to, memantine (CAS No. 19982-08-2) and salts and solvates thereof, or in combination with dual acetylcholinesterase inhibitors and NMDA glutamate receptor antagonists, including but not limited to, huperzine A (CAS No. 102518-79-6) and salts and solvates thereof, or in combination with, but not limited to, in combination with glucagon-like peptide 1 (GLP-1) agonists, including liraglutide (CAS No. 204656-20-2) and its salts and solvates, exenatide (CAS No. 141732-76-5) and its salts and solvates, or in combination with retinoids, including but not limited to acitretin (CAS No. 55079-83-9) and its salts and solvates, or in combination with nilvadipine (CAS No. 75530-6 in combination with calcium channel blockers (CCBs) including, but not limited to, nitrendipine (CAS No. 39562-70-4) and its salts and solvates, nimodipine (CAS No. 66085-59-4) and its salts and solvates, or in combination with angiotensin receptor blockers including, but not limited to, valsartan (CAS No. 137862-53-4) and its salts and solvates;in combination with tetracycline antibiotics, including minocycline (CAS number 10118-90-8) and salts and solvates thereof, or in combination with a monoclonal antibody selected from the group consisting of aducanumab, bapineuzumab, solanezumab, gantenerumab, crenezumab, BAN2401, GSK933776, AAB-003, SAR228810, BIIB037 / BART, ABBV-8E12, BIIB092 and UCB0107, or in combination with a glycosidase (O-GlcNAcase) inhibitor, including but not limited to carbidopa (carbodopa), pa), or in combination with dopamine prodrugs, including levodopa, optionally in combination with dopamine receptor agonists, including but not limited to pramipexole, rotigotine, ropinirole, amantadine, or in combination with anticholinergics, such as benztropine, trihexyphenidyl, or in combination with MAO-B inhibitors, including but not limited to safinamide, selegiline, and rasagiline, or in combination with COMT inhibitors, including but not limited to entacapone, opicapone, and tolcapone.

[0073] Thus, the treatment methods and pharmaceutical compositions of the present invention may employ succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or pharma- ceutically acceptable solvates thereof in monotherapy. However, the methods and compositions may also be used in polytherapy, in which one or more succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or pharma- ceutically acceptable solvates thereof are co-administered in combination with one or more other therapeutic agents.

[0074] In the above embodiments, the combination of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine succinate salt or a pharma- ceutically acceptable solvate thereof and other therapeutically active agents may be administered separately or together with each other in terms of dosage form, and sequentially or simultaneously in terms of their administration time. Thus, administration of one component agent may be prior to, simultaneous with, or subsequent to administration of the other component agent.

[0075] Generally, for pharmaceutical use, the succinate salts of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine or pharma- ceutically acceptable solvates thereof can be formulated as pharmaceutical compositions comprising at least one succinate salt or pharma- ceutically acceptable solvate thereof of the present invention, at least one pharma- ceutically acceptable carrier, diluent, excipient and / or adjuvant, and optionally one or more further therapeutic agents and / or active ingredients.

[0076] As a non-limiting example, the pharmaceutical composition may be in a form suitable for oral administration, parenteral administration (e.g., by intravenous, intramuscular or subcutaneous injection, or intravenous infusion), topical administration, inhalation, skin patch, implant, suppository, etc. Such suitable dosage forms, which may be solid, semi-solid or liquid depending on the mode of administration, as well as methods and carriers, diluents and excipients for use in their preparation will be apparent to those skilled in the art; reference is made to the latest edition of Remington's Pharmaceutical Sciences. The pharmaceutical composition may be formulated in solid form and redissolved or suspended before use. A preferred pharmaceutical composition of the succinate salt or solvate thereof of the present invention is a solid dosage form suitable for oral administration.

[0077] Some preferred, but non-limiting examples of dosage forms include tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols, ointments, creams, lotions, soft and hard gelatin capsules, suppositories, drops, sterile injectable solutions for bolus administration and / or continuous administration, and sterile packaged powders, which are typically reconstituted prior to use, which dosage forms may be combined with carriers, excipients, and diluents, which are themselves appropriate for such formulations. For example, they may be formulated with lactose, dextrose, sucrose, sorbitol, mannitol, starch, agar, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, polyethylene glycol, cellulose, (sterile) water, methylcellulose, methyl- and propylhydroxybenzoates, talc, magnesium stearate, edible oils, vegetable oils and mineral oils, or suitable mixtures thereof. Particularly preferred dosage forms of the succinate salts and their solvates of the present invention are soft and hard capsules, especially soft and hard gelatin capsules, preferably hard gelatin capsules, which are formulated with at least one microcrystalline cellulose excipient, especially Avicel® PH101. The pharmaceutical compositions may optionally contain other substances commonly used in pharmaceutical formulations, such as lubricants, wetting agents, emulsifying and suspending agents, dispersing agents, disintegrating agents, stabilizing agents, isotonic agents, extenders, fillers, preservatives, sweetening agents, flavoring agents, fragrances, coloring agents, antibacterial and / or antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, partitioning agents, flow regulators, release agents, etc. The compositions may also be formulated to provide quick, sustained, or delayed release of the active compounds contained therein.

[0078] The pharmaceutical compositions of the present invention are preferably in unit dosage form and may be suitably packaged, for example in a box, blister, vial, bottle, sachet, ampoule, or any other suitable single-dose or multi-dose holder or container, which may be appropriately labeled; optionally with one or more leaflets containing product information and / or instructions for use. Generally, such unit dosage forms will contain 0.05-1000 mg, usually 1-500 mg, for example about 10, 25, 50, 100, 200, 300 or 400 mg of at least one compound of the present invention per unit dosage form.

[0079] Typically, depending on the condition to be prevented or treated and the route of administration, the active compounds of the invention will normally be administered in an amount of 0.01 to 100 mg, more often 0.1 to 50 mg, for example 1 to 25 mg, for example about 0.5, 1, 2, 5, 10, 15, 20 or 25 mg per kg of patient body weight per day, which may be administered as a single daily dose, divided into one or more daily doses, or essentially continuously, for example using intravenous infusion.

[0080] All references to compounds of formula II include references to solvates, particularly hydrates, multi-component complexes and liquid crystals thereof.

[0081] Compounds disclosed throughout this application were named using ChemDraw® Ultra version 11.0 (CambridgeSoft, Cambridge, Mass., USA).

[0082] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine free base can be obtained as disclosed in WO 2006 / 051489. Succinic acid salts and solvates thereof can be prepared according to techniques known in the art, such as those involving precipitation, crystallization, recrystallization, lyophilization, phase transfer or ion exchange resins.

[0083] definition The following definitions and explanations pertain to terms used throughout this application, including both the specification, figures, and claims.

[0084] When describing the compounds of the present invention, the terms used, unless otherwise indicated, should be construed in accordance with the following definitions.

[0085] Unless otherwise stated, any reference herein to a compound of the invention means the compound of formula II per se and its pharma- ceutically acceptable solvates. All references to compounds of formula II include references to their pharma- ceutically acceptable solvates and all crystalline forms thereof.

[0086] The term "administration," or variations thereof (e.g., "administer"), means providing an active agent or ingredient (e.g., N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine), either alone or as part of a pharma- ceutically acceptable composition, to a patient whose condition, symptom, or disease is to be treated or prevented.

[0087] The term "Alzheimer's disease," as used herein, refers to all forms of Alzheimer's disease, including, but not limited to, sporadic and familial forms.

[0088] The phrase "inhibiting" as used herein refers to partial inhibition or reduction, as well as complete inhibition.

[0089] The term "human" refers to subjects of both genders and at all stages of development (i.e., neonate, infant, juvenile, adolescent, adult).

[0090] The term "patient" refers to a warm-blooded animal, more preferably a human, awaiting or receiving medical care, or being or will be the subject of a medical procedure.

[0091] "Pharmaceutically acceptable" means that the components of a pharmaceutical composition are compatible with each other and not harmful to the patient.

[0092] The terms "prevent", "preventing" and "prevention", as used herein, refer to a method of delaying or hindering the onset of a condition or disease and / or its attendant symptoms, a method of preventing a patient from contracting a condition or disease, or a method of reducing a patient's risk of contracting a condition or disease.

[0093] The term "sesqui" as used herein refers to 1.5 equivalents, and a sesquisuccinate salt of a compound means a succinic acid addition salt of a compound in which succinic acid is present in a 3:2 ratio compared to the free base form of the compound.

[0094] The term "solvate" is used herein to describe a compound of the present invention that contains stoichiometric or substoichiometric amounts of one or more pharma- ceutically acceptable solvent molecules, such as ethanol. The term "hydrate" is used when said solvent is water. The pharma-ceutically acceptable solvent molecules may be co-crystallized with the compound of the present invention and / or may be present in and / or adsorbed to the solid crystalline and / or amorphous phases thereof.

[0095] The compounds of the present invention include compounds of formula II as defined above, including all polymorphs and crystal habits thereof, prodrugs thereof, and isotopically labeled compounds of formula II.

[0096] The term "tauopathy" as used herein refers to disorders characterized by abnormal metabolism of tau protein, in particular abnormal phosphorylation and / or hyperphosphorylation of tau protein and / or the presence of elevated (higher than normal control levels, e.g. higher than normal control levels of an individual or population of individuals of the same age group) levels of tau or tau isoforms or tau polypeptides and / or pathological forms of tau in cells, tissues or fluids, preferably brain tissue and / or cerebrospinal fluid. More specifically, tauopathy refers to disorders in which intracellular aggregates of abnormally modified tau protein, such as neurofibrillary tangles (NFTs), Pick bodies, tufted astrocytes and / or myocyte inclusions, preferably at least neurofibrillary tangles (NFTs), are observed.

[0097] The term "therapeutically effective amount" (or more simply, "effective amount"), as used herein, means an amount of an active agent or ingredient (e.g., N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine) sufficient to achieve the desired therapeutic or prophylactic effect in the patient to which it is administered.

[0098] The terms "treat", "treating" and "treatment", as used herein, are intended to include alleviating, relieving or arresting a condition or disease and / or its attendant symptoms.

[0099] The present invention will be better understood with reference to the following examples, which are intended to represent specific embodiments of the invention and are not intended to limit the scope of the invention. [Brief description of the drawings]

[0100] [Figure 1] FIG. 2 shows the XRPD 2Θ diffractogram of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate, Form A. [Diagram 2] FIG. 2 shows the XRPD 2Θ diffractogram of the crystal form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine disulfate, Form B. [Diagram 3] FIG. 2 shows the XRPD 2Θ diffractogram of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt, Form 1. [Figure 4] FIG. 2 shows the XRPD 2Θ diffractogram of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Diagram 5] FIG. 1 shows the XRPD 2Θ diffractogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sequi-succinic acid salt hemihydrate (0.5 equivalents of water). [Figure 6] FIG. 1 shows the XRPD 2Θ diffractogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt monohydrate (1.1 equivalents of water). [Figure 7] FIG. 1 shows an HPLC chromatogram of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 8] FIG. 2 shows the TG / DT thermogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 9]FIG. 1 shows a DSC thermogram (first heating cycle) of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 10] FIG. 1 shows a GVS isotherm plot of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 11] FIG. 1 shows a GVS kinetics plot of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 12] FIG. 1 shows the post-GVS XRPD 2Θ diffractogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 13] FIG. 1 shows the FT-IR spectrum of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 14] FIG. 1 shows the H-NMR spectrum (DMSO-d, 500.12 MHz) of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 15] FIG. 1 shows the C quantitative NMR spectrum (DMSO-d, 500.12 MHz) of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 16]FIG. 1 shows the XRPD 2Θ diffractogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1, from a 7-day stability study. [Figure 17] FIG. 1 shows an overlay of XRPD 2Θ diffractograms of a batch of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, Form 1. [Figure 18] FIG. 2 shows the TG / DT thermogram of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Figure 19] FIG. 2 shows a DSC thermogram of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Figure 20] FIG. 1 shows the H-NMR spectrum (MeOH-d, 500.12 MHz) of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Figure 21] FIG. 1 shows a DVS isotherm plot of a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Figure 22] FIG. 1 shows the DVS kinetics plot of the crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate, Form 2. [Diagram 23]FIG. 1 shows the XRPD (4-35° 2Θ) diffractogram of a blend of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt Form 1 and Avicel® PH101 formulated in a hard gelatin capsule and stored at room temperature. [Figure 24] FIG. 1 shows the XRPD (4-35° 2Θ) diffractogram of a blend of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinic acid salt Form 1 and Avicel® PH101 formulated in a hard gelatin capsule and stored at 40° C. / 75% RH. [Diagram 25] Figure 1. Effect of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate form 1 on viability (A), neurite network (B) and tau phosphorylation (AT100) (C) in cortical neurons cultured with microglia after 72 h of Aβ1-42 injury. Results are expressed as percentages relative to control (CTR) condition as mean ± SEM (n=4-6). One-way ANOVA followed by Fisher's test. *; ** or *** indicate p<0.05; p<0.01 or p<0.001 vs. Aβ1-42 or ### vs. CTR, with p<0.05 considered significant. [Figure 26] Figure 1 shows the effect of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate form 1 on microglial cell activation (A) and PGRN release (B) in cortical neurons cultured with microglia after 72 h of Aβ1-42 injury. Results are expressed as percentages relative to control (CTR) condition as mean ± SEM (n=4-6). One-way ANOVA followed by Fisher's test. *; ** or *** indicate p<0.05; p<0.01 or p<0.001 vs. Aβ1-42 or ### vs. CTR, with p<0.05 considered significant. [Figure 27] Figure 1 shows the effect of pre-incubation or co-incubation of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate form 1 on viability (A), neurite network (B) and α-synuclein aggregation (C) in primary midbrain TH(+) neurons after 48 hours of MPP+ injury. Results are expressed as percentages relative to control condition as mean ± SEM (n=4-6). One-way ANOVA followed by Fisher's test. ####p<0.0001 vs. control; *<0.05; **p<0.01; ***p<0.001 or ****p<0.0001 vs. MPP+. [Figure 28] Figure 1 shows the effect of pre-incubation or co-incubation of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate form 1 on viability (A), neurite network (B) and α-synuclein aggregation (C) in primary midbrain neurons TH(+) after 24 h of rotenone injury. Results are expressed as percentages relative to control condition as mean ± SEM (n=4-6). One-way ANOVA followed by Fisher's test. ####p<0.0001 vs. control; *<0.05; **p<0.01; ***p<0.001 or ****p<0.0001 vs. rotenone. EXAMPLES

[0101] Chemical Examples The following abbreviations are used throughout this specification: °C: degree Celsius; w: water activity, DMSO: dimethyl sulfoxide, DSC: differential scanning calorimetry, GVS: gravimetric vapor sorption, δ: NMR chemical shift in ppm, eq: equivalent, EDTA: ethylenediaminetetraacetic acid, eq.: equivalent, g: gram, h: hour, HDPE: high density polyethylene, HPLC: high performance liquid chromatography, Hz: hertz, FT-IR: Fourier transform infrared, L: liter, M: mol / L, mM: mmol / L, μM: μmol / L, Me: methyl, MEK: methyl ethyl ketone, mg: milligram, MHz: megahertz, min: minute, mL: milliliter, mm: millimeter, mol: mole, mmol: millimole, μmol: micromole, MPP + : 1-methyl-4-phenylpyridin-1-ium, nm: nanometers, NMR: nuclear magnetic resonance, PBS: phosphate buffered saline, PLM: polarized light microscopy, PGRN: progranulin, ppm: parts per million, RH: relative humidity, RPM: revolutions per minute, rt: retention time, RT: room temperature (approximately 15-25°C), s: seconds, TFA: trifluoroacetic acid, TG / DTA: thermogravimetric / differential thermal analysis, UV: ultraviolet, v: volume, VH-XRPD: variable humidity X-ray powder diffraction, WB: western blot, XRPD: X-ray powder diffraction.

[0102] All reported temperatures are in degrees Celsius (° C.); all reactions were conducted at room temperature (RT) unless otherwise noted.

[0103] The experimental set-up or purification procedures used in the present invention, unless otherwise specified in detail, are assumed to be known to the skilled artisan and are described in standard reference manuals such as: i) Gordon, AJ; Ford, RA "The Chemist's Companion - A Handbook of Practical Data, Techniques, and References", Wiley: New York, 1972; ii) Vogel's Textbook of Practical Organic Chemistry, Pearson Prentice Hall: London, 1989; iii) P. Heinrich Stahl and Camille G. Wernuth "Handbook of Pharmaceutical Salts", Wiley VCH.

[0104] HPLC analysis. Method A: Equipment: Dionex Ultimate 3000 Column: Supelco Ascentis Express C18 15 x 4.6 mm 2.7 μm Column temperature: 50℃ Autosampler temperature: Room temperature UV wavelength: 275nm Injection volume: 20 μL Flow rate: 1mL / min Mobile phase A: 0.1% TFA in water Mobile phase B: 0.1% TFA in acetonitrile Gradient Program:

[0105] [Table 1]

[0106] Method B: In a variant, HPLC analysis was performed using a Zorbax Extend C18 150×4.6 mm 3.5 μm column with the same parameters as above.

[0107] NMR analysis NMR experiments were performed on a Bruker AVIIIHD spectrometer equipped with a DCH cryoprobe operating at 500.12 MHz for proton and carbon. Experiments were performed in deuterated DMSO, and each sample was prepared at a concentration of approximately 10 mM. Further analysis was performed using D 2 O and / or methanol-d 4 NMR studies were occasionally performed in . Chemical shifts are expressed in parts per million (ppm, δ units). Coupling constants are expressed in Hz. Abbreviations for the multiplicities observed in NMR spectra are as follows: s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), br (broad). UV analysis (for capsule blend uniformity only)

[0108] [Table 2]

[0109] The samples were measured using a quartz cuvette with a path length of 10 mm. Initially, UV scanning was performed in the range of 190 nm to 400 nm for solutions of salts at a concentration of approximately 20 μg / mL prepared in water. The same solvent was used for baseline correction. A fixed 280 nm wavelength was used primarily to check the blend homogeneity of the salt formulations.

[0110] X-ray powder diffraction (XRPD) XRPD analysis was performed on a PANalytical X'pert pro equipped with a PIXcel detector (128 channels) scanning the samples from 3 to 35° 2θ. The material was gently ground to release aggregates and loaded onto a multi-well plate with a Mylar polymer film to support the sample. The multi-well plate was then placed into the diffractometer and the diffractometer was operated in transmission mode (step size 0.0130° 2θ, step time 18.87 s) using a 40 kV / 40 mA generator setting with Cu Kα radiation (α 1 λ=1.54060 Å;α 2 = 1.54443 Å;β = 1.39225 Å;α 1 :α 2Ratio = 0.5) was used for analysis. Data were visualized and images were generated using the HighScore Plus 4.7 desktop application (PANalytical, Inc., 2017).

[0111] Thermogravimetric / differential thermal analysis (TG / DTA) Approximately 5 mg of material was weighed into an open aluminum pan and loaded into a simultaneous thermogravimetric / differential thermal analyzer (TG / DTA) and held at room temperature. The sample was then heated at a rate of 10°C / min from 20°C to 300°C while the change in sample mass was recorded along with any differential thermal events (DTA). Nitrogen was pumped to 300 cm 3 was used as a purge gas at a flow rate of 1 / min.

[0112] Differential Scanning Calorimetry (DSC) Approximately 5 mg of material was weighed into an aluminum DSC pan and non-hermetically sealed with a perforated aluminum lid. The sample pan was then loaded into a Seiko DSC6200 (equipped with a chiller), cooled, and held at 20°C. Once a stable heat flow response was obtained, the sample and reference were heated to 180°C at a rate of 10°C / min and the resulting heat flow response was monitored. Nitrogen was poured into 50 cm 3 was used as a purge gas at a flow rate of 1 / min.

[0113] Infrared Spectroscopy (IR) Infrared spectroscopy was performed on a Bruker ALPHA P spectrometer. Sufficient material was placed in the center of the spectrometer plate and a spectrum was obtained using the following parameters: Resolution: 4cm -1 Background scan time: 16 scans Sample scan time: 16 scans Data collection: 4000~400cm -1 Result spectrum: Transmittance Software: OPUS version 6

[0114] Gravimetric Vapor Sorption (GVS) Approximately 10-20 mg of sample was placed in a mesh vapor sorption balance pan and loaded onto a Hiden Analytical IGASorp moisture sorption analyzer balance. The sample was subjected to a ramping profile from 40-90% relative humidity (RH) in 10% increments, maintaining the sample at each step until a stable mass was achieved (98% step completion, minimum step length 30 min, maximum step length 60 min) at 25 °C. After completion of the sorption cycle, the sample was dried down to 0% RH using the same procedure and finally returned to the starting point of 40% RH. Two cycles were performed. The mass change during the sorption / desorption cycle was plotted, which allowed the hygroscopicity of the sample to be determined.

[0115] Dynamic Vapor Sorption (DVS) Approximately 10-20 mg of sample was placed in a mesh vapor sorption balance pan and loaded into a Surface Measurement Systems Intrinsic Dynamic Vapor Sorption Balance. The sample was subjected to a ramping profile from 40-90% relative humidity (RH) in 10% increments, maintaining the sample at each step until a stable mass was achieved at 25 °C (dm / dt 0.004%, minimum step length 30 min, maximum step length 500 min). After completion of the sorption cycle, the sample was dried to 0% RH using the same procedure and then subjected to a second sorption cycle back to 40% RH. Two cycles were performed. The mass change during the sorption / desorption cycle was plotted, which allowed the hygroscopicity of the sample to be determined. XRPD analysis was then performed on any solids that were retained.

[0116] Variable Humidity X-ray Powder Diffraction (VH-XRPD) VH-XRPD analyses were performed on a Philips X'Pert Pro multipurpose diffractometer equipped with a humidity chamber. Cu K radiation (α 1 λ=1.54060 Å;α 2 = 1.54443 Å;β = 1.39225 Å;α 1 :α 2The sample was scanned from 4 to 35.99° 2θ using a 350 nm NMR spectrometer (ratio = 0.5). Measurements were performed at 50%, 60%, 70%, 80%, and 90%. The sample was held at 90% for 1 hour and 30 minutes. Measurements were taken at 30 minute intervals.

[0117] Unless otherwise specified, solvents and reagents were purchased and used as received from commercial vendors.

[0118] Example 1 N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate form 1: synthesis and characterization of the crystalline form 514.6 mg of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine was weighed into a 20 mL scintillation vial. 10 mL of methyl ethyl ketone (99% purity) was added to the vial, which was stirred at 40° C. using a temperature controlled block, stir plate, and magnetic needle. A clear solution was not observed, so an additional 5 mL of MEK was added to aid dissolution at 40° C. A clear solution was obtained; the clear solution at 40° C. was polish filtered using a PTFE filter (0.45 micron) and syringe. The filtered solution was added back into a clean 20 mL scintillation vial and reheated to 40° C. 142.5 mg of succinic acid (1 molar equivalent) was added to the vial. A clear solution was initially observed. After stirring at 40° C. for 30 minutes, crystallization of material was observed. The experiment was temperature cycled from 40°C to 5°C in 3 hour cycles over 20 hours. At 5°C, the slurry was filtered using a Buchner flask and funnel under vacuum using a grade 1 Whatman filter paper (pore size = 11 μm). The wet cake was washed with 2.5 mL of chilled (5°C) MEK and dried under reduced pressure at 40°C for 2 hours. The dried isolated solid was analyzed by XRPD, TG / DTA and HPLC. The filtered mother liquor was analyzed for concentration by HPLC. An isolated yield of 78.5% was achieved, and an HPLC yield of 93.5% was determined based on the mother liquor concentration (see Table 1).

[0119] [Table 3]

[0120] HPLC (Method A) showed a purity of 99.2%; rt = 10.65 min (Figure 7). The XRPD 2Θ diffractogram showed that the material was crystalline (Figure 3) and contained peaks at diffraction angles of 2θ=3.8°±0.2° (100%), 10.3°±0.2° (11.3%), 12.4°±0.2° (6.8%), 16.2°±0.2° (23.5%), 17.9°±0.2° (11.9%), 19.8°±0.2° (10.2%), 20.4°±0.2° (13.0%), 23.8°±0.2° (23.3%) and 26.7°±0.2° (9.8%) when illuminated with a CuKα light source. The TG trace showed a mass loss of 0.4% from the start of heating to about 160 °C, which is due to surface moisture. The DT trace showed an endothermic event with an onset of about 130 °C (peak at 132 °C), which is due to a melting event. A broad endothermic event was also observed after melting with an onset of about 209 °C (peak at about 228 °C); this is associated with decomposition (Figure 8). Another batch of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, sesquisuccinate was prepared and further characterized by HPLC, XRPD, DSC, GVS, FT-IR, NMR and VH-XRPD. HPLC (Method A) showed a purity of 98.4%. The XRPD2 Θ diffractogram was identical to that of the previous batch (see top graph of FIG. 12 with reference to FIG. 3). DSC on the first heating cycle showed a sharp endothermic event with an onset of about 128° C. and a peak at 131° C. This was followed by a small exothermic event with a peak at 142° C. and then a smaller exothermic event with a peak at 147° C. (FIG. 9); DSC analysis on the first cooling and second heating cycles showed no significant events in the thermogram. GVS analysis revealed that the material took up about +0.1 wt.% at 70% RH, followed by a sharp increase of about +18.9 wt.% (roughly 7.1 equivalents of water) up to 90% RH. It is possible that channel hydrates may form at this stage. This is then quickly lost to 70% RH and gradually to 0% RH (Figure 10). The GVS kinetics plot can be seen in Figure 11, which showed a sudden increase in mass from 70 to 90% RH. XRPD analysis after GVS revealed that the material remained as the same crystalline form after exposure to GVS humidity conditions (Top: XRPD of material; Bottom: XRPD of material after GVS). The FT-IR spectrum is shown in FIG. DMSO-d 6 In 1 H and quantitative 13 The C NMR spectra are shown in Figures 14 and 15, respectively. 1 H NMR spectrum (500.12MHz - DMSO-d 6 ):δ(ppm): 7.13 (2H dd J1 = 6Hz, J2 = 3Hz), 6.87 (2H dd J1 = 6Hz, J2 = 3Hz), 6.71 (1H br s), 3.30 (2H t J = 7Hz), 2.42 (6H m, 2.33 4H dt J1 = 16Hz, J2=7Hz), 2.04 (4H d J = 7Hz), 1.74 (2H quintet J = 7Hz), 1.67 (2H septet J = 7Hz), 1.52 (2H quintet J = 7Hz), 0.85 (12H d J = 7Hz) ppm. quantitative 13 C NMR spectrum (121.16MHz - DMSO-d 6):δ(ppm): 174.3, 156.0, 119.5, 111.9, 63.9 56.1, 55.6, 53.0 (d), 29.8, 26.8, 26.6, 24.2, 21.3.Quantification 13 C NMR confirmed the stoichiometry and successful formation of the sesquisuccinate salt. VH-XRPD of sesquisuccinate Form 1 up to 90% RH revealed no change to crystallinity or morphology after exposure to 90% RH for up to 1 hour 30 minutes, remaining in the same crystalline form.

[0121] 7-day stability test A 7-day stability study was performed as follows: 15 mg of salt was weighed into three 2 mL vials. The vials were then placed at 40° C. / 75% RH, 80° C. and ambient light; after one week, the solids were analyzed by XRPD and HPLC purity (Method A). XRPD analysis of solids recovered after a 7-day stability study (at 40° C. / 75% RH, 80° C. and ambient light) showed no change to crystallinity or morphology after exposure to these conditions ( FIG. 16 ). HPLC analysis (Method A) of the solids recovered from the 7-day stability study showed no change in purity at each stability condition, values ​​are reported in Table 2.

[0122] [Table 4]

[0123] Solubility Experiments Solubility evaluation in unbuffered water showed the material to be highly soluble with a value of >500 mg / mL. pH measurements were performed giving a value of 5.28. Approximately 20 mg of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, sesquisuccinate salt Form 1 was weighed into 3 x 2 mL vials. 100 μL of the appropriate buffer was added to form a slurry. The results are listed in Table 3.

[0124] [Table 5]

[0125] Synthesis scale-up The same experimental conditions were used to synthesize two further batches of this sesquisuccinate salt Form 1, starting from 20 g and 79 g of the free base. The batches had purity of >99%, as checked by HPLC (Method A), with yields of 69% and 73%, respectively. An overlay of the XRPD2Θ diffractograms of all batches (514 mg, 20 g and 79 g scales) is shown in FIG. N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, sesquisuccinate Form 1 was reproducibly obtained on a multigram scale in good yield using one-pot salt formation / crystallization. Sesquisuccinate Form 1 is very stable (purity and polymorphic form), highly crystalline, highly soluble, not hygroscopic up to 90% relative humidity and stable under stress conditions. Therefore, this product is a suitable API and of interest especially for solid dosage forms.

[0126] Example 2 N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine trisuccinate form 2: synthesis and characterization of the crystalline form 10 mg of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine was weighed into a 1.5 mL vial and a minimum amount of ethanol was added to achieve complete dissolution of the free base. Two equivalents of succinic acid were added using a 0.5 M stock solution (596.41 mg succinic acid dissolved in 10 mL ethanol). The vial was temperature cycled from room temperature to 40° C. (4 hour cycles) with stirring for 6 days. Precipitation was observed and the solid was isolated by centrifugal filtration and then dried under vacuum at 40° C. for approximately 24 hours. The solid was analyzed by HPLC, XRPD, TG / DT, DSC, DVS, FT-IR, NMR and VH-XRPD. HPLC (Method A) showed a purity of 99.9%. The XRPD 2Θ diffractogram showed that the material was crystalline (see FIG. 4) and contained peaks at diffraction angles of 2θ=5.3°±0.2° (100%), 15.0°±0.2° (26.7%), 15.3°±0.2° (57.4%), 16.8°±0.2° (25.3%), 17.9°±0.2° (92.3%), 20.5°±0.2° (30.1%), 21.2°±0.2° (25.5%), 23.9°±0.2° (24.2%), 24.3°±0.2° (65.3%) and 26.6°±0.2° (31.5%) when illuminated with a CuKα light source. The TG trace (see FIG. 18) from the TG / DT analysis showed no mass loss up to 150° C., indicating that the material contained no residual solvent. Mass loss associated with salt dissociation was observed at temperatures above 150° C. The DT trace showed an endothermic event associated with bond dissociation / melting of the salt form with an onset of about 155.1° C. (peak 159.1° C.). The DSC thermogram (see FIG. 19) showed that trisuccinate Form 2 melted with an onset of about 155.8° C. (peak 157.7° C.). MeOH-d 4 It was carried out in 1 1 H NMR confirmed that the salt contained 3 equivalents of succinic acid (see Figure 20). 1H NMR spectrum (500.12MHz - MeOH-d 4 ):δ(ppm): 7.28 (2H dd J1 = 6Hz, J2 = 3Hz), 7.10 (2H dd J1 = 6Hz, J2 = 3Hz), 3.48 (2H t J = 7Hz), 2.78 (6H br s), 2.67 (7H m), 2.56 (12H s), 2.41 (4H d J = 7Hz), 1.95 (2H quintet J = 7Hz), 1.87 (2H septet J = 7Hz), 1.79 (2H sextet J = 7.4Hz), 1.33 (5H br m), 0.97 (12H d J = 6.7Hz) ppm. DVS analysis reveals that the material takes up about +0.1 wt.% at 70% RH, which is followed by a sharp increase of about +9.92 wt.% (roughly 4.3 equivalents of water) up to 90% RH, which is then quickly lost up to 70% RH and gradually down to 0% RH (Figure 21). The DVS isotherm plot correlated with a Type I isotherm indicating no change in structure throughout the DVS cycle, as confirmed by the DVS kinetic plot (Figure 22), where no significant change in mass was observed. XRPD analysis after DVS showed that the material remained as trisuccinate Form 2. 7-day stability showed that Form 2 was stable at 50° C., 80° C. and under ambient light conditions. The solubilities in different buffers are reported in Table 4.

[0127] [Table 6]

[0128] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine, trisuccinate form 2, was obtained in good yield using one-pot salt formation / crystallization. Trisuccinate form 2 is very stable (purity and polymorphic form), highly crystalline, highly soluble, not hygroscopic up to 90% relative humidity and stable under stress conditions. Therefore, this product is a suitable API and of interest especially for solid dosage forms.

[0129] Example 3 Preparation and Stability of Capsules Containing N-(3-(4-(3-(Diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine Sesquisuccinate Form 1 Preparation of formulation blends Into a cylindrical drum shell having a volume of 220 mL, 7.5 g of Avicel® PH101 was weighed, followed by 15 g of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate Form 1, and finally 7.5 g of Avicel® PH101. Adding the Form 1 and Avicel® PH101 excipients in this manner improved mixing of the two compounds. The final blend is 50:50 w / w Form 1:Avicel® PH101. The formulation was mixed using a TorPac ProMixer powder mixer / blender by rotating the drum at a constant speed of 55-65 rpm for 5 minute intervals with reversal every 60 seconds. After a 5 minute period, a subsample was taken to prepare a solution equivalent to 20 μg / mL Form 1 in water. This was analyzed by UV against the same salt standards and concentrations to determine the Form 1 content in the blend. Mixing was performed until a homogenous blend was obtained. As the excipients were not water soluble, the sample solution was filtered through a 0.45 μm PTFE syringe filter prior to analysis. Standards were used to ensure that the membrane selected did not adversely affect the recovery of the analytes. Once a homogenous blend was obtained, 100 hard gelatin size 1 white / white capsules were filled. The uniformity of the filled capsules was assessed by weighing 10 filled capsules from each batch. The variation in the empty shells was considered to be insignificant.

[0130] Stability sample preparation of formulation blends The filled capsules were distributed into HDPE screw-top bottles, 10 per bottle, and placed in storage. Four bottles were stored at each condition: room temperature and 40° C. / 75% RH. Ten capsules were for the initial time point and were used to determine mass uniformity. At each time point, five capsules were cut open and the contents distributed into 20 mL scintillation vials. The powders were then mixed with a spatula and sampled as required for analysis by HPLC (Method B) and XRPD.

[0131] Blend Uniformity Blend uniformity was established when the three parallel subsample concentrations matched within 5%. Sesquisuccinate Form 1 only required 30 minutes of mixing to achieve a homogenous powder.

[0132] [Table 7]

[0133] In contrast, the disulfate Form B blend required up to 60 minutes as small agglomerates were observed to form upon mixing. Excessive shear with disulfate Form B is required to break down the agglomerates and speed up the mixing process (i.e., shorten to 30 minutes), but may also adversely affect crystallinity.

[0134] Capsule uniformity: mass of filled capsules The powder formulation was easily filled into capsules due to the free flowing nature of the blend and suitable capsule uniformity was achieved.

[0135] [Table 8]

[0136] HPLC stability assay No change in purity was observed throughout the stability storage, where N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate Form 1 was maintained throughout 4 weeks storage of capsules at room temperature or 40° C. / 75% RH.

[0137] [Table 9]

[0138] XRPD stability analysis No change in crystalline morphology was observed throughout the stability storage, where N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate Form 1 was retained throughout 4 weeks of storage of capsules at room temperature or 40° C. / 75% RH (see FIG. 23 and FIG. 24).

[0139] N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate Form 1 was efficiently blended with microcrystalline cellulose excipient to provide a free-flowing powder that was easily dispensed into capsules and 4-week stability at room temperature and 40° C. / 75% RH was achieved, with the purity and crystalline morphology of the API remaining unchanged.

[0140] Biological Examples Aβ 1-42 Effects on irradiated cortical neurons Cortical neuron culture Rat cortical neurons cultured with microglia were cultured as described by Callizot et al., J Neurosci Res. 2013, 91:706-716, with modifications to include microglial cells. Pregnant female rats (Wistar rats; Janvier Labs, France) were cultured at 15 days of gestation for 24 hours at 4°C for 12 h at 4°C for 1 h at 4°C. 2After deep anesthesia with 500 mg / ml, the animals were sacrificed by cervical dislocation. The fetuses were then collected and immediately placed in ice-cold L15 Leibovitz's medium containing 2% penicillin (10,000 U / ml) and streptomycin (10 mg / ml) solution (PS) and 1% bovine serum albumin (BSA). The cortices were treated with trypsin-EDTA solution at a final concentration of 0.05% trypsin and 0.02% EDTA for 20 min at 37°C. Dissociation was stopped by the addition of Dulbecco's modified Eagle's medium (DMEM) with 4.5 g / liter glucose, containing DNase I grade II (final concentration 0.5 mg / ml) and 10% fetal calf serum (FCS). The cells were mechanically dissociated by three forced passages through the tip of a 10 mL pipette. The cells were then centrifuged at 515 x g for 10 min at 4°C. The supernatant was discarded and the pellet was resuspended in defined culture medium consisting of Neurobasal medium containing 2% solution of B27 supplement, 2 mmol / liter L-glutamine, 2% PS solution, 10 ng / mL brain-derived neurotrophic factor (BDNF), 2% heat-inactivated horse serum, 2% heat-inactivated FCS, 1 g / L glucose, 1 mM sodium pyruvate, and 100 μM non-essential amino acids. Viable cells were counted in a Neubauer cytometer using the trypan blue exclusion test. Cells were seeded at a density of 45,000 cells per well in poly-L-lysine precoated 96-well plates (for immunostaining) and incubated at 37°C in air (95%)-CO. 2 The cells were cultured in a 5% CO incubator and the culture medium was changed every 2 days.

[0141] Test compounds and human Aβ 1-42 exposure After 11 days in culture, the cortical neurons were intoxicated with Aβ solution (see below). 1-42 The preparation was performed according to the procedure described by Callizot et al., 2013. Briefly, Aβ 1-42Peptides were dissolved in the defined culture medium described above at an initial concentration of 40 μM. This solution was gently stirred in the dark at 37° C. for 3 days and used immediately after appropriate dilution in control medium to the concentration used (5 μM Aβ containing 0.5 μM Aβ oligomers (AβO) measured by WB). 1-42 Preparation). Control medium consisted of defined culture medium (as above). Test compounds were dissolved in water and mixed in the culture medium. Compounds were administered to primary cortical neurons cultured with microglia for 72 hours to induce Aβ 1-42 Co-administered with the preparation.

[0142] immunostaining After permeabilization with 0.1% saponin, cells were blocked for 15 min with PBS containing 1% fetal bovine serum. Cells were then incubated for 2 h with: a) For MAP-2 neurons: chicken polyclonal antibody (Ab) anti-microtubule associated protein 2 (MAP-2) at a dilution of 1 / 1000 in PBS containing 1% fetal bovine serum and 0.1% saponin. This antibody specifically binds to neurons and neurites, allowing the study of neuronal cell viability and neurite networks. b) For AT100 tau phosphorylation: Mouse monoclonal Ab anti-tau, phosphorylated at sites Thr212 and Ser214 (AT100), at a dilution of 1 / 400 in PBS containing 1% fetal bovine serum and 0.1% saponin. c) For OX-41 microglia: Rabbit polyclonal Ab anti-SIRP alpha / CD172a (OX-41) at a dilution of 1 / 400 in PBS containing 1% fetal bovine serum and 0.1% saponin. This Ab binds specifically to microglial cells and allows the assessment of their activation.

[0143] These antibodies were revealed with Alexa Fluor 350 donkey anti-chicken IgG, Alexa Fluor 488 goat anti-mouse IgG, and Alexa Fluor 568 goat anti-rabbit IgG at a dilution of 1 / 400 in PBS containing 1% FCS, 0.1% saponin for 1 h at room temperature.

[0144] For each condition, 30 pictures were taken automatically per well at 20x magnification using ImageXpress (Molecular Devices). All images were generated using the same acquisition parameters. Analysis was performed automatically by using the Custom Module Editor (Molecular Devices).

[0145] The following readings were investigated: - Neuronal viability: total number of neurons (MAP-2 staining) - Neuritic network (MAP-2 staining at μm scale) - Phospho-tau inside neurons: Area of ​​colocalization with AT100 and MAP-2 (μm of overlap) 2 ) - Microglial activation: total area of ​​microglial cells (μm 2 OX41 staining in units

[0146] Extracellular Progranulin quantification The levels of PGRN in the culture medium were determined by ELISA (Progranulin (rat) ELISA lit, Adipogen, Coger) according to the manufacturer's recommendations. Briefly, 100 μL of supernatant was added directly into the well strip for 1 h at 37°C. Then, 100 μL of detection antibody was added for 1 h at 37°C, and 100 μL of HRP-labeled streptavidin was added for 1 h at 37°C. Finally, 100 μL of TMB substrate solution was added for 10 min at room temperature. Optical density (OD) was evaluated spectrophotometrically at 450 nm wavelength using a Glomax device (Promega). The activity of peroxidase is proportional to the concentration of PGRN.

[0147] statistical analysis Results are expressed as percentage of control. All values ​​represent the mean + / - SEM (standard error of the mean) from 4-6 wells per condition. Graphical and statistical analysis was performed for different conditions (ANOVA followed by Dunnett's or Fisher's t-test) using GraphPad Prism software version 7.04. *p<0.05 was considered significant.

[0148] result Neuronal Viability: Aβ 1-42 Intoxication with DMSO significantly reduced the viability of cortical neurons compared to the control group (Figure 25A). Sesquisuccinate form 1 was neuroprotective at the highest doses (10 nM-100 nM). Neurite network: The total length of the neurite network is 1-42 was significantly decreased after injury (FIG. 25B). The neurite network was significantly longer in the presence of the highest doses of sesquisuccinate form 1 (10 nM-100 nM). AT100:Aβ 1-42 Upon application of , a significant increase in AT100 was observed in MAP-2 cortical neurons (Figure 25C). Sesquisuccinate Form 1 significantly reduced tau hyperphosphorylation at doses above 1 nM. Activation of microglial cells: As expected, Aβ 1-42 Intoxication with caused activation of microglial cells compared to the control group (Figure 26A). At the doses investigated, sesquisuccinate form 1 was able to reduce the activation of microglial cells. Extracellular PGRN:Aβ 1-42 In the presence of , the level of PGRN in the supernatant was significantly lower when compared to that of the control group. Sesquisuccinate Form 1 significantly increased the level of extracellular PGRN at a concentration of 10 nM (Figure 26B).

[0149] In line with these results, it can be concluded that sesquisuccinate form 1 is a) neuroprotective, b) preserves neurite network, b) reduces tau hyperphosphorylation, d) reduces microglial activation and thus neuroinflammation, and e) can promote the release of progranulin neurotrophic factor in the supernatant of cultured cells.Therefore, the succinate of the present invention is useful for the treatment of neurodegenerative diseases, particularly tauopathies and Parkinson's disease.

[0150] MPP + or effects on rotenone-damaged midbrain neurons Culturing midbrain neurons Rat dopaminergic neurons were cultured as described in Visanji et al., FASEB J. 2008, vol. 22(7):2488-2497 and Callizot et al., PlosOne 2019: https: / / doi.org / 10.1371 / journal.pone.0215277. Briefly, pregnant female rats (Wistar) at day 15 of gestation were cultured in a CO 2 The rats were sacrificed using deep anesthesia by chamber and cervical dislocation. The midbrains from 15-day-old rat embryos (Janvier, France) were dissected under a microscope. The embryonic midbrains were removed and placed in ice-cold Leibovitz (L15) medium containing 2% penicillin-streptomycin (PS) and 1% BSA. The ventral part of the midbrain flexure, a region of the developing brain rich in dopaminergic neurons, was used for cell preparation. Mesencephalons were dissociated by trypsinization (a solution with a final concentration of 0.05% trypsin and 0.02% EDTA) for 20 min at 37°C. The reaction was stopped by the addition of DMEM containing DNAase I grade II (0.5 mg / mL) and 10% FCS. The cells were then mechanically dissociated by passing three times through a 10 ml pipette. The cells were then centrifuged for 10 min at 180 x g at +4°C on a layer of BSA (3.5%) in L15 medium. The supernatant was discarded and the cell pellet was resuspended in defined culture medium consisting of Neurobasal supplemented with B27 (2%), L-glutamine (2 mM), and 2% PS solution, and 10 ng / mL BDNF and 1 ng / mL glial-derived neurotrophic factor (GDNF). Viable cells were counted in a Neubauer cytometer using the trypan blue exclusion test. Cells were seeded at a density of 40,000 cells / well in 96-well plates (precoated with poly-L-lysine) and incubated in 5% CO 2 The cells were maintained in a humidified incubator in a 95% air atmosphere at 37° C. Half of the medium was replaced with fresh medium every 2 days. For 96 well plates, only 60 wells were used: the wells in the first and last rows and columns were not used (to avoid any edge effects) and were filled with sterile water.

[0151] Test compounds and mitochondrial stress Vehicle: culture medium (0.1% PBS). Pretreatment: On day 4, sesquisuccinate form 1 was solubilized in the culture medium and added to the cultures for 48 h. MPP+ injury: On day 6 and 48 hours after or immediately after incubation with sesquisuccinate form 1, MPP + was added to a final concentration of 4 μM and diluted into control medium still in the presence of compound for 48 h. Rotenone injury: On day 6 and 48 hours after incubation with sesquisuccinate form 1 or immediately following that incubation, rotenone was added to a final concentration of 10 nM and diluted into control medium still in the presence of compound for 24 hours.

[0152] immunostaining After injury (24 or 48 hours), the cell culture supernatant was removed and the cells were fixed with a solution of 4% paraformaldehyde in PBS, pH=7.3, for 20 minutes at room temperature. The cells were washed twice in PBS. Cell membrane permeabilization and blocking of non-specific binding sites was performed with a solution of PBS containing 0.1% saponin and 1% FCS for 15 minutes at room temperature. The cells were then incubated with: a) For tyrosine hydroxylase (TH): for 2 hours at room temperature with a monoclonal anti-TH antibody raised in mice at a dilution of 1 / 10000 in PBS containing 1% FCS, 0.1% saponin. b) For alpha synuclein (α-syn): 2 hours at room temperature with a polyclonal anti-α-syn antibody raised in rabbits at a dilution of 1 / 200 in PBS containing 1% FCS, 0.1% saponin.

[0153] Primary antibodies were revealed with Alexa Fluor 488 goat anti-mouse IgG and Alexa Fluor 568 goat anti-rabbit IgG, both at a dilution of 1 / 400, in PBS containing 1% FCS, 0.1% saponin for 1 h at room temperature. Cell nuclei were labeled with Hoechst dye (1 / 1000).

[0154] For each condition, 20 pictures (representing the entire well area) were automatically taken at 10x magnification using the same acquisition parameters using ImageXpress® (Molecular Devices). From the images, analysis was performed automatically by MetaXpress® (Molecular Devices).

[0155] The following readings were investigated: - Neuronal viability: total number of TH neurons (TH staining), - Neurite network: Total length of neurite network of TH-positive neurons (unit: μm) - α-syn aggregation (μm 2(area of ​​overlap between TH and α-syn staining in units)

[0156] statistical analysis Results are expressed as percentages relative to the control. All values ​​represent the mean + / - SEM (standard error of the mean) from 4-6 wells per condition. Statistical analysis (ANOVA followed by Fisher's LSD test) and graphs for the different conditions were performed using GraphPad Prism software version 7.04. p<0.05 was considered significant.

[0157] result MPP + Effects of sesquisuccinate form 1 on TH(+) neurons injured by acetaminophen Neuronal viability: MPP + Intoxication with tetracycline significantly reduced the viability of dopaminergic (TH positive) neurons compared to the control group. The sesquisuccinate form 1 was neuroprotective at a dose of 50 nM (Figure 27A). Neurite network: The total length of the neurite network is determined by MPP + The integrity of the neurite network was significantly improved with the 50 nM dose of sesquisuccinate form 1 (FIG. 27B). α-syn aggregation: MPP + Upon application of 500 nM sesquisuccinate form 1, a significant increase in α-syn aggregation was observed in dopaminergic neurons. This aggregation was significantly reduced after preincubation with sesquisuccinate form 1 at all concentrations tested. Co-incubation with 50 or 100 nM sesquisuccinate form 1 significantly reduced α-syn aggregation (FIG. 27C).

[0158] Effect of sesquisuccinate form 1 on rotenone-injured TH(+) neurons Neuronal viability: Intoxication with rotenone induced a significant loss of dopaminergic neurons compared to the control group. Sesquisuccinate form 1 was significantly neuroprotective at doses of 10 and 50 nM when preincubated. However, it significantly increased neuronal viability at all concentrations when administered directly with rotenone (Figure 28A). Neuritic network: The integrity of the neurite network was significantly decreased after rotenone injury. Both pretreatment and cotreatment with sesquisuccinate form 1 significantly improved the neurite network at all doses from 10 to 100 nM (Figure 28B). α-syn aggregation: Rotenone significantly increased the aggregation of α-syn in dopaminergic neurons. This pathological aggregation was significantly reduced when sesquisuccinate form 1 was preincubated or applied directly with rotenone (10-100 nM). Notably, the aggregation of α-syn was prevented when 100 nM sesquisuccinate form 1 was co-administered (Figure 28C).

Claims

1. Succinic acid salt of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine and pharma- ceutically acceptable solvates thereof.

2. Formula II 【Chemistry 1】 [wherein x is 1 to 4] 2. The succinate salt of claim 1, having the formula:

3. The succinate salt and its pharma- ceutically acceptable solvates according to claim 2, characterized in that x is 1.4 to 3.

1.

4. The succinate salt and its pharma- ceutically acceptable solvates according to claim 2, characterized in that x is 1.4 to 1.

6.

5. 3. The succinate salt and its pharma- ceutically acceptable solvates according to claim 2, characterized in that x is 1.

5.

6. 3. The succinate salt and its pharma- ceutically acceptable solvate according to claim 2, characterized in that, under a crystalline form having an X-ray powder diffraction (XRPD) pattern including peaks at diffraction angles 2θ=3.8°±0.2°, 10.3°±0.2°, 12.4°±0.2°, 16.2°±0.2°, 17.9°±0.2°, 19.8°±0.2°, 20.4°±0.2°, 23.8°±0.2° and 26.7°±0.2°, x being 1.5 when irradiated with a CuKα light source.

7. The succinate salt and its pharma- ceutically acceptable solvates according to claim 2, characterized in that x is between 2.9 and 3.

1.

8. 8. A pharmaceutical composition comprising the succinate salt of any one of claims 1 to 7, or a pharma- ceutically acceptable solvate thereof, and at least one pharma- ceutically acceptable carrier, diluent, excipient and / or adjuvant.

9. 1. A process for making a crystalline form of N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine sesquisuccinate, comprising: - Step 1: N-(3-(4-(3-(diisobutylamino)propyl)piperazin-1-yl)propyl)-1H-benzo[d]imidazol-2-amine is dissolved in an organic solvent; - step 2: heating the reaction medium to temperature B, defining temperature B as comprised between 30 and 50°C; - step 3: adding a substantially equimolar amount of succinic acid; - step 4: the reaction medium is stirred at temperature B for 0.25 to 4 hours; - step 5: temperature A is defined as the temperature comprised between 0 and 10°C, and the reaction medium is subjected to a temperature cycle from temperature A to temperature B in 2-4 hour cycles over a period of 10-30 hours; - step 6: the reaction medium is cooled to a temperature A; - step 7: filtering the reaction medium at temperature A; - step 8: washing the filter cake with said organic solvent at temperature A; - Step 9: Dry the filter cake at a temperature of 30-50°C A method comprising the steps of:

10. 8. The succinate salt, or a pharma- ceutically acceptable solvate thereof, of any one of claims 1 to 7 for use as a medicament.

11. 8. A succinate salt, or a pharma- ceutically acceptable solvate thereof, according to any one of claims 1 to 7, for use in treating and / or preventing a disease selected from neurodegenerative diseases and diseases in which dysfunction of tau protein phosphorylation is observed.

12. 8. The succinate salt, or a pharma- ceutically acceptable solvate thereof, according to any one of claims 1 to 7, for use in delaying the onset in a patient of a disease selected from neurodegenerative diseases and diseases in which dysfunction of tau protein phosphorylation is observed.

13. 13. The succinate salt, or a pharma- ceutically acceptable solvate thereof, for use according to claim 11 or 12, wherein the disease is a tauopathy.

14. Tauopathies include Alzheimer's disease, Guam amyotrophic lateral sclerosis and parkinsonism-dementia complex, argyrophilic granule disease, chronic traumatic encephalopathy, corticobasal degeneration, dementia pugilistica, diffuse neurofibrillary tangle disease with calcifications, familial British dementia, familial Danish dementia, frontotemporal dementia (FTD), frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), frontotemporal lobar degeneration (FTLD), frontotemporal dementia-granulin subtype (FTD-GRN), Gerstmann-Sträussler-Scheinker disease, Guadeloupe-type parkinsonism, Hallervorden-Spatz disease, inclusion body myositis, multisystem 14. The succinate salt or a pharmacologic acceptable solvate thereof for use according to claim 13, wherein the disease is selected from the group consisting of cerebral atrophy, Steinert myotonic dystrophy, myotonic dystrophy type II, neurodegeneration with brain iron accumulation, Niemann-Pick disease type C, non-Guam motor neuron disease with neurofibrillary tangles, Paget's disease, Pick's disease, postencephalitic parkinsonism, progressive subcortical gliosis, progressive supranuclear palsy (PSP), SLC9A6-associated mental retardation, subacute sclerosing panencephalitis, dementia with neurofibrillary tangles, multi-infarct dementia, ischemic stroke, chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), stroke, and leukotauopathy with globular glial inclusions.

15. 13. The succinate salt, or a pharma- ceutically acceptable solvate thereof, for use according to claim 11 or 12, wherein the disease is Parkinson's disease.

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