(19) TZZ__T (11) EP 1 945 654 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C07J 13/00 (2006.01) A61K 31/575 (2006.01) 19.08.2015 Bulletin 2015/34 A61P 31/00 (2006.01) (21) Application number: 06805540.9 (86) International application number: PCT/DK2006/000600 (22) Date of filing: 30.10.2006 (87) International publication number: WO 2007/051468 (10.05.2007 Gazette 2007/19) (54) PREPARATION OF AN ANTIBIOTIC CRYSTALLINE FUSIDIC ACID HERSTELLUNG EINER ANTIBIOTISCHEN KRISTALLINEN FUSIDINSÄURE PREPARATION D’UNE SUBSTANCE ANTIBIOTIQUE CRISTALLINE DE L’ ACIDE FUSIDIQUE (84) Designated Contracting States: • ANDERSEN, Niels, Rastrup AT BE BG CH CY CZ DE DK EE ES FI FR GB GR DK-2720 Vanløse (DK) HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (56) References cited: BE-A- 619 287 DE-A1- 1 468 178 (30) Priority: 31.10.2005 US 731247 P ES-A1- 2 204 331 ES-A1- 2 208 110 FR-A- 1 326 076 GB-A- 930 786 (43) Date of publication of application: RU-C2- 2 192 470 23.07.2008 Bulletin 2008/30 • HIKINO HIROSHI ET AL: "Fungal metabolites. II. (73) Proprietor: LEO PHARMA A/S Fusidic acid, a steroidal antibiotic from Isaria 2750 Ballerup (DK) kogane" CHEMICAL AND PHARMACEUTICAL BULLETIN, PHARMACEUTICAL SOCIETY OF (72) Inventors: JAPAN, TOKYO, JP, vol. 20, no. 5, 1972, pages • JENSEN, Jan 1067-1069, XP008080392 ISSN: 0009-2363 DK-2980 Kokkedal (DK) Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 1 945 654 B1 Printed by Jouve, 75001 PARIS (FR) EP 1 945 654 B1 Description FIELD OF THE INVENTION 5 [0001] The present invention relates to a novel crystalline form of fusidic acid, to its preparation, pharmaceutical compositions containing it, and to the use of said crystalline fusidic acid form that can be used as a medicament in treatment of infectious diseases. BACKGROUND OF THE INVENTION 10 [0002] Fusidic acid [CAS6990-06-3] [Nature, Vol. 193, No. 4819, p. 987, 1962] which can be isolated from the fer- mentation broth of Fusidium coccineum is the most antibiotically active compound of the fusidanes and is the only fusidane used clinically in treatment of infectious diseases. Fusidic acid (Fucidin ®) is used clinically for the treatment of severe staphylococcal infections, particularly in bone and joint infections, in both the acute and the intractable form of 15 the disease (The Use of Antibiotics, 5th Ed., A. Kucers and N.McK. Bennett (Eds.), Butterworth 1997, pp. 580-587, and references cited therein). 20 25 30 35 [0003] Although fusidic acid is most commonly used against staphylococci, it is also used against several other gram- positive species. The clinical value of fusidic acid is also due to its efficient distribution in various tissues, low degree o f toxicity and allergic reactions and the absence cross-resistance with other clinically used antibiotics. Fusidic acid is widely used in local therapy for a number of skin and eye infections caused by staphylococci. It is generally given in combination with common antibiotics such as penicillins, erythromycins or clindamycin. It has also been used as an 40 alternative to vancomycin for the control of Gostridium difficile. Compared to staphylococci, several other gram-positive cocci are often less susceptible to fusidic acid. As an example, streptococcal species are generally up to 100-fold less sensitiveto fusidic acid thanstaphylococci [Kucherset al; supra]. Other sensitive bacteria include gram-positive anaerobic cocci, such as Peptococcus and Peptostreptococcus spp., aerobic or anaerobic gram-positive bacteria, such asCo- rynebacterium diphtheriae, Clostridium tetani, Clostridium difficile and Clostridium perfringens. Gram-negative bacteria 45 are resistant except for Neisseria spp. and Legionella pneumophila. The drug is highly potent against both intracellular and extracellular M. leprae. [0004] The solid form, such as the crystal form, of a drug substance or active pharmaceutical ingredient used in a pharmaceutical formulation or medicament is important based on solubility, dissolution rate, hygroscopicity, bioavaila- bility, and stability differences between the different solid forms. Thus the existence of various solid forms, such as 50 polymorphism or pseudo polymorphism can affect the properties of the quality of the drug product. [0005] Hence, a specific crystal form, including solvates and hydrates, might be preferable over another one. Further- more certain forms may be preferable depending on the specific formulation and/or application. For example, the prop- erties of a drug, such as the dissolution rate of the active ingredient, may be tuned by the proper choice of a certain crystal form, or mixtures thereof. 55 [0006] In a specific commercial pharmaceutical formulation, fusidic acid is presently marketed [see Monographs in the European Pharmacopeia 5.0] as a hemihydrate, which is the only hemihydrate form which has been described. [0007] Patent GB 930,786 discloses salts of fusidic acid with organic and inorganic bases, solvates of fusidic acid, namely a benzene solvate and a methanol solvate. This patent further discloses an unspecified fusidic acid form with 2 EP 1 945 654 B1 -1 22 IR absorption bands (KBr) at 1265, 1385, 1695, 1730 and 3450 cm and having a specific rotation [α]D of minus 9 degrees (1% solution in CHCl 3) obtainable by crystallisation of the methanol solvate of fusidic acid from ether. However, this form is distinct from the form of the present invention evident from the depicted IR spectrum in GB 930,786 which indicates that this form actually corresponds to the presently marketed hemihydrate form. 5 [0008] Solvates and salts of fusidic acid have also been disclosed in British patent GB 999,794. Patent ES 2208110 discloses two solvent free crystalline forms of fusidic acid called Form I and Form II, and a crystalline hemihydrate called Form III which is identical to the presently marketed hemihydrate, respectively. The crystalline forms were identified and characterised by IR spectroscopy, differential scanning calorimetry, X-ray diffraction and melting points. [0009] Patent WO 96/03128 discloses tablets containing a sodium salt form of fusidic acid and WO 86/03966 describes 10 an ophthalmic gel composition comprising an undefined form of suspended fusidic acid. SUMMARY OF THE INVENTION [0010] The present invention surprisingly provides a novel crystalline form of fusidic acid and a process for the prep- 15 aration of said crystalline fusidic acid. [0011] In one aspect, this invention relates to crystalline fusidic acid characterised by exhibiting one or more of the following features a)-f), respectively: a) a fourier transform (FT-NIR) Raman spectrum exhibiting one or more of the following intensity peaks at 3008, 20 2937, 2871, 172 5, 1707, 1666, 1651, 1468, 1379, 1348, 1195, 1078, 1032, 972, 917, 792, 745, 696, 612, 569, 547, 527, 463, 175, 120, or 86 (63 cm-1), respectively; b) an attenuated total reflectance fourier transform infrared (FTIR-ATR) spectrum exhibiting one or more of the following attenuated total reflectance peaks at 3644, 3489, 2992, 2937, 2871, 1722, 1708, 1442, 1381, 1352, 1283, 1255, 1218, 1204, 1175, 1149, 1109, 1069, 1048, 1028, 962, 941, 917, 851, 828, 791, 750, 690, or 656 ( 63 cm’ 1), 25 respectively; c) a near infrared (FT-NIR) spectrum exhibiting one or more of the following absorbance peaks at 10414, 8373, 7115, 6846, 6503, 5824, 4996; 4889, 4831, 4680, 4365, 4306, or 4067 ( 65 cm-1), respectively; d) an X-ray powder diffractogram (XRD) exhibiting one or more of the following angles of reflection 2 θ (60.1) at 7.2, 9.3, 9.9, 12.6, 13.1, 14.3, 14.7, 14.9, 15.4, 16.7, 17.9, 18.1, 18.5, 18.9, 19.5, 20.8, 21.8, 22.7, 23.5, 24.0, 24.4, 25.3, 30 26.0, 26.6, 26.8, 28.2, 28.9, or 29.7, respectively; e) a 13C CP/MAS solid-state NMR spectrum exhibiting one or more of the following resonances at 173.9, 169.3, 146.1, 137.0, 133.3, 120.6, 76.2, 71.1, 69.1, 49.7, 49.4, 45.0, 39.9, 38.5, 36.9, 35.8, 34.5, 32.7, 30.9, 29.5, 28.0, 26.5, 20.7, 20.0, 18.0, or 16.9 (60.5) ppm, respectively; or f) one or more of the following single-crystal X-ray diffraction experimental data: crystal system = monoclinic, space 35 group = P21, a [Å] = 12.2, b [A] = 8.0, c [A] = 13.9, α [°] = 90 β [°] = 94, γ [°] = 90, cell volume [Å3] = 1360, or Z = 2, respectively. [0012] In yet another aspect, this invention relates to isolated crystalline fusidic acid of the present invention as defined above which has a polymorphic purity of at least 80%, such as 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 40 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. [0013] In yet another aspect, this invention relates to isolated fusidic acid of the present invention as defined above which has a degree of crystallinity of at least 80%, such as %, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. [0014] In yet another aspect, this invention relates to a mixture or composition of crystalline forms of fusidic acid, 45 including pseudopolymorphs of fusidic acid, comprising crystalline fusidic acid of the present invention as defined above.