HK1087718A - Crystal forms of azithromycin - Google Patents

Description

Crystalline forms of azithromycin

Background

The present invention relates to a crystalline form (crystal form) of Azithromycin (Azithromycin). Azithromycin is commercially available and is an effective antibiotic for the treatment of numerous bacterial infections. The crystalline forms of the invention are also useful as antibiotics in mammals, including humans, as well as fish and birds.

Azithromycin has the following structural formula:

azithromycin is described and claimed in U.S. Pat. nos. 4,517,359 and 4,474,768. It is also known as 9-deoxo-9 a-aza-9 a-methyl-9 a-homoerythromycin a.

Other patents or patent applications that cover azithromycin, either directly or indirectly, include: EP 298,650, claiming azithromycin dihydrate; U.S. Pat. No. 4,963,531, claims a method for treating Toxoplasma gondii strains (strains of Toxoplasma gondii species); us patent 5,633,006 claims chewable tablets or slurries of a bitter taste reduced pharmaceutical composition; U.S. patent 5,686,587 claims intermediates useful in the preparation of azithromycin; U.S. patent No. 5,605,889, claims an oral dosage form that reduces the "food effect" associated with azithromycin administration; U.S. patent 6,068,859, claims a controlled release dosage form containing azithromycin; us patent 5,498,699, claims compositions containing azithromycin and a divalent or trivalent metal; EP 925,789 claims a method of treating ophthalmic infections; chinese patent application CN 1123279A, relates to water-soluble salt of azithromycin; chinese patent application CN1046945C, relating to azithromycin sodium dihydrogen phosphate double salt; chinese patent application CN 1114960a, relates to azithromycin crystals; chinese patent application CN 1161971a, relates to azithromycin crystals; chinese patent application CN 1205338A, relates to a method for preparing azithromycin water-soluble salt; international patent publication WO 00/32203, directed to an ethanolate of azithromycin; and european patent application EP 984,020, relating to azithromycin monohydrate isopropanol clathrate.

Summary of The Invention

The present invention relates to crystalline forms of azithromycin. The term "crystalline form" or "form" as used herein, unless otherwise noted, refers to one or more crystalline forms of azithromycin.

Specifically, the present invention relates to a crystalline form of azithromycin, wherein said crystalline form is selected from the group consisting of form C, D, E, F, G, H, J, M, N, O, P, Q and form R, wherein said forms are as defined herein. F. G, H, J, M, N, O and P belong to family I (f)amily) azithromycin belonging to the monoclinic system P2₁Space group (space group), cell dimension (a) is 16.3 ± 0.3 angstrom, b is 16.2 ± 0.3 angstrom, c is 18.4 ± 0.3 angstrom, β is 109 ± 2 °. C. D, E and R belongs to Azithromycin of family II and belongs to orthorhombic system P2₁2₁2₁Space group, unit cell size is 8.9 ± 0.4 angstrom, b is 12.3 ± 0.5 angstrom, and c is 45.8 ± 0.5 angstrom. Form Q is distinct from families I and II.

The molecular formula of the F-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·0.5C₂H₅OH is a single crystal structure and is the monohydrate half ethanol solvate of azithromycin. Form F is further characterized by 2-5 wt% water and 1-4 wt% ethanol in the powder sample and has powder X-ray diffraction 2 θ peaks as defined in Table 9. Of type F¹³The C ssNMR (solid state nuclear magnetic resonance) spectrum has two chemical shift peaks at approximately 179. + -. 1ppm, which are 179.5. + -. 0.2ppm and 178.6. + -. 0.2ppm, a set of five peaks between 6.4 and 11.0ppm, and ethanol peaks at 58.0. + -. 0.5ppm and 17.2. + -. 0.5 ppm. The solvent peak may be broad and relatively weak in intensity.

The invention also relates to substantially pure azithromycin form F, azithromycin form F substantially free of azithromycin form G and azithromycin form F substantially free of azithromycin dihydrate.

The invention further relates to a process for the preparation of azithromycin form F, which comprises treating azithromycin with ethanol, dissolving completely at 40-70 ℃, cooling, while reducing ethanol or adding water to effect crystallization. Also included are processes for preparing substantially pure (substentially pure) azithromycin form F, azithromycin form F substantially free of azithromycin form G, and azithromycin form F substantially free of azithromycin dihydrate.

The molecular formula of the G-type azithromycin is C₃₈H₇₂N₂O₁₂·1.5H₂O, is a single crystal structure and is the sesquihydrate of azithromycin. Form G is further characterized by the presence of a powder sample2.5-6 wt% water and < 1 wt% organic solvent, and having powder X-ray diffraction 2 theta peaks as defined in table 9. Of type G¹³The C ssNMR spectrum has a chemical shift peak at about 179. + -.1 ppm, which is 179.5. + -. 0.2ppm (possible < 0.3ppm split), with a set of five peaks between 6.3 and 11.0 ppm.

The invention also relates to substantially pure azithromycin form G and to azithromycin form G substantially free of azithromycin dihydrate.

The invention further relates to a process for preparing substantially pure azithromycin form G and substantially azithromycin form G free of azithromycin dihydrate by treating azithromycin with a mixture of methanol and water or acetone and water, dissolving completely at 40-60 ℃, and cooling for crystallization.

The molecular formula of the H-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·C₃H₈O₂Is monohydrate half-1, 2-propanediol solvate of azithromycin.

The molecular formula of the J-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·0.5C₃H₇OH is a single crystal structure and is the monohydrate half normal propyl alcohol solvate of azithromycin. Form J is further characterized by having 2-5 wt% water and 1-5 wt% 1-propanol in the powder sample and having powder X-ray diffraction 2 θ peaks as defined in Table 9. Of the J type¹³The C ssNMR spectrum had two chemical shift peaks at approximately 179. + -. 1ppm, 179.6. + -. 0.2ppm and 178.4. + -. 0.2ppm, a set of five peaks between 6.6 and 11.7ppm, and an n-propanol peak at 25.2. + -. 0.4 ppm. The solvent peak may be broad and relatively weak in intensity.

The invention further relates to a process for preparing form J by treating azithromycin with n-propanol, fully dissolving at 25-55 ℃, cooling while adding water to effect crystallization.

The molecular formula of the M-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·0.5C₃H₇OH, which is a monohydrate hemiisopropanol solvate of azithromycin. Form M is further characterized as containing 2-5 wt% water and 1-4 wt% 2-propanol in the powder sample and having powder X-ray diffraction 2 θ peaks as defined in Table 9. Of type M¹³The C ssNMR spectrum had a chemical shift peak at approximately 179. + -. 1ppm, which was 179.6. + -. 0.2ppm, one peak at 41.9. + -. 0.2ppm, a set of six peaks between 6.9 and 16.4ppm, and an isopropanol peak at 26.0. + -. 0.4 ppm. The solvent peak may be broad and relatively weak in intensity.

The invention also relates to substantially pure azithromycin form M, azithromycin form M substantially free of azithromycin form G and azithromycin form M substantially free of azithromycin dihydrate.

The invention further relates to a process for preparing substantially pure M-type azithromycin, M-type azithromycin substantially free of G-type azithromycin and M-type azithromycin substantially free of azithromycin dihydrate, by treating azithromycin with isopropanol, completing the dissolution at 40-60 ℃, cooling after reducing the isopropanol, or adding water after cooling, for crystallization.

Azithromycin type N is a mixture of family I isoforms. The mixture may contain variable percentages of isomorphs F, G, H, J, M and others, and variable amounts of water and organic solvents, such as ethanol, isopropanol, n-propanol, propylene glycol, acetone, acetonitrile, butanol, pentanol, and the like. The weight percent of water may be 1-5%, the total weight percent of organic solvents may be 2-5%, and the content of each solvent is 0.5-4%. The N-type samples show all characteristic peaks of the members of family I in various ratios. The N-type crystal can be characterized as "mixed crystal" of the I family isomorph and "crystalline solid solution".

Chemical shifts of the N-type are represented by combinations of family I isoforms (isomorphs). Since isomorphs are mixed in variable proportions in the N-type crystalline solid solution, peaks may differ in chemical shift ± 0.2ppm and relative intensity and width.

The molecular formula of the P-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·0.5C₅H₁₂O, is a monohydrate half n-pentanol solvate of azithromycin.

The molecular formula of the Q-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·0.5C₄H₈O, is a monohydrate hemitetrahydrofuran solvate of azithromycin.

The molecular formula of the R-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·C₅H₁₂O, is the monomethylt-butylether solvate of azithromycin monohydrate.

The molecular formula of the D-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·C₆H₁₂Is a single crystal structure and is a monohydrate-cyclohexane solvate of azithromycin. Form D is further characterized by 2-6 wt% water and 3-12 wt% cyclohexane in the powder sample and has powder X-ray diffraction 2 θ peaks as defined in Table 9. Of type D¹³The C ssNMR spectrum showed a chemical shift peak at about 179. + -. 1ppm, which was 178.1. + -. 0.2ppm, peaks at 103.9. + -. 0.2ppm, 95.1. + -. 0.2ppm, 84.2. + -. 0.2ppm, with a set of three peaks between 8.4 and 11 ppm.

The invention further relates to a process for preparing form D by suspending azithromycin dihydrate with cyclohexane.

The molecular formula of the E-type azithromycin is C₃₈H₇₂N₂O₁₂·H₂O·C₄H₈O, is a monohydrate-tetrahydrofuran solvate of azithromycin.

The invention further relates to azithromycin in an amorphous state and to a process for preparing amorphous azithromycin which comprises removing water and/or solvent from the azithromycin crystal lattice. The X-ray diffraction powder pattern of amorphous azithromycin did not show a sharp 2 theta peak but had two rounded peaks (broad rounddedpeak). The first peak exists between 4 ° and 13 °. The second peak exists between 13 ° and 25 °.

The present invention also relates to a pharmaceutical composition for treating bacterial or protozoal infections in mammals, fish or birds comprising a therapeutically effective amount of the above crystalline compound, or amorphous azithromycin, and a pharmaceutically acceptable carrier.

The invention is also directed to a method of treating a bacterial infection or a protozoal infection in a mammal, fish or bird comprising administering to said mammal, fish or bird a therapeutically effective amount of the crystalline compound described above, or amorphous azithromycin.

The present invention also relates to a process for preparing a crystalline form of azithromycin which comprises suspending azithromycin in a suitable solvent, or dissolving azithromycin in a heated organic solvent or organic solvent/water solution, and cooling the solution while reducing the volume of the solvent to precipitate crystalline azithromycin, or dissolving azithromycin in a solvent or solvent mixture and adding water to the solution to precipitate crystalline azithromycin. Azithromycin is prepared in an amorphous state by heating and crystallizing azithromycin in vacuum.

The term "treatment" as used herein, unless otherwise indicated, means the treatment or prevention of a bacterial or protozoal infection as provided by the methods of the present invention, including curing the infection, reducing its symptoms, or delaying its progression. The verb "treat" is defined as the noun "treat" above.

The term "substantially free" when referring to a designated crystalline form of azithromycin means containing less than 20% (by weight) of the designated crystalline form, more preferably, containing less than 10% (by weight) of the designated crystalline form, more preferably, containing less than 5% (by weight) of the designated crystalline form, and most preferably, containing less than 1% (by weight) of the designated crystalline form. For example, azithromycin form F substantially free of azithromycin dihydrate means form F containing 20% (by weight) or less of azithromycin dihydrate, more preferably 10% (by weight) or less of azithromycin dihydrate, and most preferably 1% (by weight) or less of azithromycin dihydrate.

The term "substantially pure" when referring to a specified crystalline form of azithromycin means that the specified crystalline form contains less than 20% (by weight) of the remaining components, e.g., alternating polymorphic or isomorphic crystalline forms of azithromycin. It is preferred that the substantially pure azithromycin contains less than 10% (by weight, more preferably less than 5% (by weight), and most preferably less than 1% (by weight) of alternative crystalline forms of polymorphic or isomorphic forms of azithromycin.

The term "substantially free of azithromycin dihydrate" when referring to a quantity (bulk) of crystalline azithromycin or a composition containing crystalline azithromycin means that the crystalline azithromycin contains less than about 5% (by weight) azithromycin dihydrate, more preferably less than about 3% (by weight) azithromycin dihydrate, and most preferably less than about 1% (by weight) azithromycin dihydrate.

Unless otherwise indicated, the terms "bacterial infection" or "protozoal infection" as used herein include bacterial infections and protozoal infections and diseases caused by such infections in mammals, fish and birds, as well as conditions involving bacterial infections and protozoal infections, which may be treated or prevented by administration of antibiotics, such as the compounds of the present invention. Such bacterial and protozoal infections and conditions involving such infections include, but are not limited to, the following: pneumonia (pneumonia), otitis media (otitis media), sinusitis (sinusitis), bronchitis (bronchitis), tonsillitis (tonsillitis), and mastoiditis (mastoiditis) involving streptococcus pneumoniae (streptococcus influenzae), Moraxella catarrhalis (Moraxella catarrhalis), Staphylococcus aureus (Staphylococcus aureus), or streptococcus digesta (streptococcus spp); pharyngitis (pharynigitis), rheumatic fever (rhematous liver) and glomerulonephritis (glomerinophthalitis) involving infection by Streptococcus pyogenes (Streptococcus pycnis), Streptococcus group C and group G, Clostridium dipetheriae or Actinobacillus haemolyticus; respiratory infections involving infection with Mycoplasma pneumoniae (Mycoplasma pneumoniae), Legionella pneumophila (Legionella pneumophila), Streptococcus pneumoniae (Streptococcus pneumoniae), Haemophilus influenzae (Haemophilus influenzae), or Chlamydia pneumoniae (Chlamydia pneumoniae); to Staphylococcus aureus (Staphylococcus aureus), coagulase-positive staphylococci (i.e., Staphylococcus epidermidis (S. epidermidis), Staphylococcus haemolyticus (S. haemolyticus), etc.), Streptococcus pyogenes (Streptococcus pyogenenes), Streptococcus agalactiae (Streptococcus agalactiae), Streptococcus C-F (Streptococcus micellae), Streptococcus viridis (Streptococcus mutans), Corynebacterium parvum (Corynebacterium minutissimum), Clostridium (Clostridium spp.) or Bartonella hensis (Bartonella hensis) infection, uncomplicated skin and soft tissue infection, abscess (abscesses) and osteomyelitis (osteopenia) and heat of production (Puveria heat); uncomplicated acute urinary tract infections involving infection with Staphylococcus saprophyticus (Staphylococcus saprophyticus) or Enterococcus (Enterococcus spp.); urethritis (urethritis) and cervicitis (cervicitis); sexually transmitted diseases involving infection by Chlamydia trachomatis (Chlamydia trachomatiis), Haemophilus ducreyi (Haeophilus ducreyi), Treponema pallidum (Treponema pallidum), Ureaplasma urealyticum (Ureapalasma urealyticum) or Neisseria gonorrhoeae (Neiserria gonorrheae); toxin diseases involving staphylococcus aureus (s.aureus) (food poisoning and Toxic shock syndrome) or A, B and group C streptococcal infections (toxindiseases); ulcers involving Helicobacter pylori (Helicobacter pylori) infection; systemic febrile syndromes (systemic febrilesyndromes) involving recurrent leptospira recurrentis (Borrelia recurrensis) infection; lyme disease (lymediasea) involving Borrelia burgdorferi (Borrelia burgdorferi) infection; to conjunctivitis (conjunctivitis), keratitis (keratitis) and dacryocystitis (dacryocystitis) infected with Chlamydia trachomatis (Chlamydia trachomatis), neisseria gonorrhoeae (Neisseriagonorrhoeae), staphylococcus aureus (s. aureus), streptococcus pneumoniae (s. pnemoniae), streptococcus pyogenes (s. pyogenes), haemophilus influenzae (h. influenzae) or listeria (Listeriaspp.); a method for treating a bacterial infection in a mammal, the method comprising treating a mammal with Mycobacterium avium or Mycobacterium intracellulare (dissemited Mycobacterium complex (MAC) disease involving Mycobacterium intracellulare infection; gastroenteritis (gastrointestinal disease) involving Campylobacter jejuni infection; enterozoonosis (intestinal Protozoa) involving Cryptosporidium spp. infection; odontogenic infection (odontogenic infection) involving Streptococcus viridis (viral streptococci) infection; cough persistence (bacterial infection) involving Bordetella pertussis infection; Aerobacter coli (Clostridium perfringens) or Streptococcus pseudopezicola (Streptococcus pneumoniae) involving Clostridium perfringens) or Bacillus sporogenes infection; and/or atherosclerosis (atherosclerosis) involving Streptococcus pneumoniae infection and/or Streptococcus pneumoniae infection Bovine respiratory disease (bovine respiratory disease) infected with pasteurella multocida (p.multocida), Mycoplasma bovis (Mycoplasma bovis), or Bordetella spp; cow intestinal disease (cownteric disease) involving infection with escherichia coli or protozoa (i.e., coccidia (coccidia), cryptosporidia, etc.); mastitis (dairy cow mastitis) in cows involving infection with staphylococcus aureus (staph. aureus), streptococcus uberis (strep. uberis), streptococcus agalactiae (strep. agalactiae), streptococcus dysgalactiae (strep. dysgalaciae), Klebsiella (Klebsiella spp.), Corynebacterium (Corynebacterium) or Enterococcus (Enterococcus spp.); porcine respiratory disease involving infection with actinobacillus pleuropneumoniae (a. pleuro), pasteurella multocida (p. multocida) or Mycoplasma (Mycoplasma spp.); porcine intestinal disease involving infection with Escherichia coli, Lawsoniaintracelularis, Salmonella (Salmonella) or Serpentis hyodysenteriae (Serpulinehyodylisinosae); bovine foot gangrene (cow foot) involving clostridium sp infection; cow metritis (cow metritis) involving escherichia coli infection; cow hairy warts (cow hair warts) involving infection by Fusobacterium necrophorum (Fusobacterium necrophorum) or horseshoe arthrobacter (bacteroides) are involved; cow red eye disease (cow pink-eye) involving Moraxella bovis (Moraxella bovis) infection; premature cow birth (cow birth) involving protozoan (i.e., neospora) infection; urinary tract infections in dogs and cats involving e.coli infections; skin and soft tissue infections in dogs and cats involving infection with staphylococcus epidermidis (staph. epidermidis), staphylococcus intermedius (staph. intermedia), coagulase-negative staphylococcus (stagase neg. staph), or pasteurella multocida (p. multocida); relates to the infection of dog and cat teeth or oral cavity infected by Alcaligenes (Alcaligenes pp.), Bacteroides (Bacteroides spp.), Clostridium (Clostridium spp.), Enterobacter (Enterobacter spp.), Eubacterium (Eubacterium), Streptococcus digestus (Peptostreptococcus), Porphyromonas (Porphyromonas) or Prevotella (Prevotella). Other bacterial infections and protozoal infections and conditions involving such infections that may be treated or prevented according to The methods of The present invention are described in J.P.Sanford et al, "The Sanford Guide to Antimicrobial Therapy," 26th Edition, (Antimicrobial Therapy, Inc., 1996).

The invention also includes isotopically-labeled compounds in which one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine, for example²H、³H、¹³C、¹⁴C、¹⁵N、¹⁸O and¹⁷and O. Such radiolabeled and stable isotope labeled compounds are useful as research or diagnostic tools.

Brief description of the drawings

Figure 1 is a calculated powder X-ray diffraction pattern for azithromycin form a. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 2 is an experimental powder X-ray diffraction pattern for azithromycin form a. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 3 is an overlay of figures 1 and 2 with the calculated diffraction pattern for azithromycin form a (figure 1) at the bottom and the experimental diffraction pattern for azithromycin form a (figure 2) at the top. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 4 is a calculated powder X-ray diffraction pattern for azithromycin form C. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 5 is a calculated powder X-ray diffraction pattern for azithromycin form D. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 6 is an experimental powder X-ray diffraction pattern for azithromycin form D. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 7 is an overlay of figures 5 and 6 with the calculated diffraction pattern for azithromycin form D (figure 5) at the bottom and the experimental diffraction pattern for azithromycin form D (figure 6) at the top. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 8 is a calculated powder X-ray diffraction pattern for azithromycin form E. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 9 is a calculated powder X-ray diffraction pattern for azithromycin form F. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 10 is an experimental powder X-ray diffraction pattern for azithromycin form F. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 11 is an overlay of figures 9 and 10 with the calculated diffraction pattern for azithromycin form F (figure 9) at the bottom and the experimental diffraction pattern for azithromycin form F (figure 10) at the top. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 12 is a calculated powder X-ray diffraction pattern for azithromycin form G. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 13 is an experimental powder X-ray diffraction pattern for azithromycin form G. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 14 is an overlay of figures 12 and 13 with the calculated diffraction pattern for azithromycin form G (figure 12) at the bottom and the experimental diffraction pattern for azithromycin form G (figure 13) at the top. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 15 is a calculated powder X-ray diffraction pattern for azithromycin form J. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 16 is an experimental powder X-ray diffraction pattern for azithromycin form J. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 17 is an overlay of figures 15 and 16 with the calculated diffraction pattern for type J azithromycin (figure 15) at the bottom and the experimental diffraction pattern for type J azithromycin (figure 16) at the top. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 18 is an experimental powder X-ray diffraction pattern for azithromycin form M. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 19 is an experimental powder X-ray diffraction pattern for azithromycin form N. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 20 is an experimental powder X-ray diffraction pattern of amorphous azithromycin. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 21 is a preparation of azithromycin form a¹³C solid state NMR spectrum.

Figure 22 is of azithromycin form D¹³C solid state NMR spectrum.

Figure 23 is of azithromycin form F¹³C solid state NMR spectrum.

Figure 24 is of azithromycin form G¹³C solid state NMR spectrum.

Figure 25 is of azithromycin form J¹³C solid state NMR spectrum.

Figure 26 is of azithromycin form M¹³C solid state NMR spectrum.

Figure 27 is of azithromycin form N¹³C solid state NMR spectrum.

Figure 28 is of amorphous azithromycin¹³C solid state NMR spectrum.

Figure 29 is a pharmaceutical tablet containing azithromycin form G¹³C solid state NMR spectrum.

Figure 30 is an experimental powder X-ray diffraction pattern for azithromycin form Q. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 31 is an experimental powder X-ray diffraction pattern for azithromycin form R. The scale on the abscissa is the angle 2 θ. The ordinate is the intensity of the counts.

Figure 32 is of azithromycin form H¹³C solid state NMR spectrum.

Figure 33 is of azithromycin form R¹³C solid state NMR spectrum.

Detailed Description

It has been found that azithromycin exists in different crystalline forms. Dihydrate form a and non-stoichiometric hydrate form B are disclosed in european patent EP 298650 and us patent 4,512,359, respectively. Sixteen others are also disclosed, namely C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q and R. These forms are either hydrates or hydrates/solvates of the azithromycin free base. Form L and form K are metastable low hydrate forms of A detected at high temperatures. The crystal structure of A, C, D, E, F, G, H, J and form O has been resolved (solve). The structural data for these crystalline forms are given below:

table 1: crystallographic data for azithromycin form a

	Type A
		Empirical formula (empirical formula) formula weight (formula weight) crystal size (crystal size) (mm) space group (space group) unit cell size Z (per formula) density (g/cm)3)R	C38H72N2O12·2H2O785.20.19×0.24×0.36P212121Orthorhombic system a ═ 14.735(5), angstrom b ═ 16.844(7), angstrom c ═ 17.81(1), angstrom α ═ 90 ° β ═ 90 ° γ ═ 90 ° 41.180.060

Table 2: crystallographic data for azithromycin form C

	C type
		Experimental type	C38H72N2O12·H2O

ChemistryFormula weight crystal size (mm) space group unit cell size Z (per formula) density (g/cm)3)R

767.150.16×0.16×0.19P212121Orthorhombic system a ═ 8.809(3), angstrom b ═ 12.4750(8), angstrom c ═ 45.59(3), angstrom α ═ 90 ° β ═ 90 ° γ ═ 90 ° 41.010.106

Table 3: crystallographic data for azithromycin form D

	D type
		Empirical formula weight crystal particle size (mm) space group unit cell size Z (per formula) density (g/cm)3)R	C38H72N2O12·H2O·C6H12851.150.52×0.32×0.16P212121Orthorhombic system a ═ 8.8710(10), ab ═ 12.506(2), c ═ 45.697(7), α ═ 90 °, β ═ 90 °, γ ═ 90 ° 41.120.0663

Table 4: crystallographic data for azithromycin form E

	E type
		Empirical formula-weighted crystal grain size (mm) space group unit cell size	C38H72N2O12·H20·C4H8O839.20.17×0.19×0.20P212121Orthorhombic system a-8.869 (3) angstrom b-12.086 (3) angstrom

Density of Z (per formula) (g/cm)3)R

c 46.00(1) angstrom alpha 90 deg. beta 90 deg. gamma 90 deg. 41.130.087

Table 5: crystallographic data for azithromycin form F

	Type F
		Empirical crystal size (mm) formula weight space group unit cell size Z (per formula) density (g/cm)3)R	C38H72N2O12·H2O·0.5C2H6O0.14×0.20×0.24790.2P21Monoclinic system a ═ 16.281(2), angstrom b ═ 16.293(1), angstrom c ═ 18.490(3), angstrom α ═ 9 ° β ═ 109.33(1) ° γ ═ 90 ° 41.130.0688

Table 6: crystallographic data for azithromycin form G

	G type
		Empirical formula weight crystal size (mm) space group unit cell dimension Z (per formula)	C38H72N2O12·1.5H2O776.00.04×0.20×0.24P21Monoclinic system a ═ 16.4069(8), angstrom b ═ 16.2922(8), angstrom c ═ 18.3830(9), angstrom α ═ 90 β ═ 110.212(2) ° γ ═ 90 ° 4 °

Density (g/cm)3)R

1.120.0785

Table 7: crystallographic data for azithromycin form H

	H type
		Empirical crystal size (mm) formula weight space group unit cell size Z (per formula) density (g/cm)3)R	C38H72N2O12·H2O·0.5C3H8O20.14×0.20×0.24805.0P21Monoclinic system a ═ 16.177(1), angstrom ═ 16.241(2), angstrom ═ 18.614(1), angstrom α ═ 90 ° β ═ 108.34(1) ° γ ═ 90 ° 41.150.0687

Table 8: crystallographic data for azithromycin form J

	J type
		Empirical formula weight crystal particle size (mm) space group unit cell size Z (per formula) density (g/cm)3)R	C38H72N2O12·H2O·0.5C3H8O796.00.40×0.36×0.20P21Monoclinic system a ═ 16.191(6), angstrom b ═ 16.237(10), angstrom c ═ 18.595(14), angstrom α ═ 90 ° β ═ 108.92(4) ° γ ═ 90 ° 41.140.0789

Table 8A: crystallographic data for azithromycin form O

	O type
		Experimental type	C38H72N2O12·0.5H2O·0.5C4H10O

Formula weight crystal size (mm) space group unit cell size Z (per formula) density (g/cm)3)R

795.040.40×0.36×0.20P21Monoclinic system a is 16.3602(11), angstrom b-16.2042 (11), angstrom c-18.5459 (12), angstrom α -90 °, β -109.66 (10), γ -90 °, 41.140.0421

Two families of isoforms are identified in these sixteen crystalline forms. Family I includes F, G, H, J, M, N, O and P-type. Family II includes C, D, E and R. Form Q is distinct from families I and II. Crystalline forms within the same family are isomorphs that crystallize in the same space group, have slight variations in unit cell parameters, and contain chemically related structures, but differ in elemental composition (elemental composition). In this case, the change in chemical composition between the isoforms results from the incorporation of different water/solvent molecules. Therefore, the isomorphs show similar, but not identical, X-ray diffraction patterns and solid state NMR spectra (ssNMR). Other techniques, such as near infrared spectroscopy (NIR), Differential Scanning Calorimetry (DSC), Gas Chromatography (GC), thermogravimetric analysis (TGA) or thermogravimetric/infrared spectroscopy (TG-IR), Karl Fischer water analysis (KF), and molecular modeling/visualization, provide confirmatory identification data for isomorphs. The dehydration/desolvation temperature was determined by means of DSC with a heating rate of 5 ℃/min.

Type C: this crystalline form is the monohydrate of (table 2) -azithromycin identified from the single crystal structure. It has P2₁2₁2₁The space group of (3), the unit cell parameters are similar to those of the D-type and the E-type; thus, it belongs to family II isoforms. The calculated powder pattern was similar to forms D and E.

Type D: form D is crystallized from cyclohexane. The form D single crystal structure shows the stoichiometry of the monohydrate-cyclohexane solvate of azithromycin (table 3). The cyclohexane molecules were found to be disturbed in the crystal lattice. The calculated water and cyclohexane contents of form D were 2.1 and 9.9%, respectively, based on single crystal data. The powder pattern and calculated powder pattern for form D are similar to those for forms C and E. The desolvation/dehydration endotherm of the D-type powder sample, analyzed by DSC at 5/min from 30 to 300 ℃, shows an onset temperature of about 87 ℃ and a broad endotherm (endotherm) of 200 ℃ and 280 ℃.

Form D was prepared by slurrying azithromycin (slurry) in cyclohexane for 2-4 days; solid azithromycin form D was collected by filtration and dried.

Type E: form E was collected in TF aqueous medium and was single crystal. By single crystal analysis, it is a monohydrate and a mono-THF solvate (table 4). With its single crystal structure, the PXRD pattern was calculated to be similar to that of form C and D, making it a family II isoform.

Form E was prepared by dissolving azithromycin in THF (tetrahydrofuran); water vapor was diffused into a saturated solution of azithromycin THF over a period of time to give form E crystals.

And (3) type F: the F-type single crystal is monoclinic space group P2₁The asymmetric unit crystallized out containing two azithromycin, two waters and one ethanol as a monohydrate/hemi ethanolate (table 5). It is isomorphic and constitutes all the family I azithromycin crystalline forms. This type of calculated PXRD pattern is similar to other family I isomorphs. Theoretical water and ethanol contents are 2.3 and 2.9%, respectively. The dehydration/desolvation endotherm for the powder sample shows an onset temperature between 110 ℃ and 125 ℃. Form F was prepared as follows: dissolving azithromycin in ethanol (1-3 volumes by weight) at a temperature of about 50-70 ℃; after complete dissolution, cooling the solution to below ambient temperature to produce a precipitate; reducing the volume of ethanol by means of vacuum distillation while stirring for 1-2 hours to increase the yield; alternatively, 0.1-2 volumes of water may be added (optionally cooled to 0-20 ℃), and the solids collected within 30 minutes after the water addition; the ethanol solution of azithromycin is cooled to below 20 c, preferably below 15 c, more preferably below 10 c, most preferably 5c prior to the addition of water to produce substantially pure form of azithromycin. Solid azithromycin form F was collected by filtration and dried.

Type G: each asymmetric unit of the G-type single crystal structure consists of two azithromycin molecules and three water molecules (table 6). This corresponds to a sesquihydrate with a theoretical water content of 3.5%. The moisture content of the type G powder samples was about 2.5 to about 6%. The total residual organic solvent of the corresponding solvent used for crystallization is less than 1%, which is well below the stoichiometry of the solvate. The initial temperature for this type of dehydration is about 110-120 ℃.

Form G can be made by adding azithromycin to a pre-mixed organic solvent/water mixture (1/1, by volume), wherein the organic solvent can be methanol, acetone, acetonitrile, ethanol, or isopropanol; stirring the mixture and heating to an elevated temperature, for example 45-55 deg.C, for 4-6 hours to allow decomposition; precipitate formation during cooling to ambient temperature; solid azithromycin form G was collected by filtration and dried.

H type: this crystalline form is a monohydrate/hemi-propylene glycol solvate of azithromycin free base (table 7). It is isolated from the formulated solution containing propylene glycol. The crystal structure of form H is isomorphic with the family I crystal form.

Azithromycin form H is prepared by: azithromycin dihydrate was dissolved in 6 volumes of propylene glycol. To the resulting azithromycin in propylene glycol solution was added 2 volumes of water and a precipitate formed. The slurry was stirred for 24 hours, the solid filtered and air dried at ambient temperature to give crystalline form H.

Type J: form J is a monohydrate/hemi-n-propanol solvate (table 8). The solvent content was calculated to be about 3.8% n-propanol and about 2.3% water. Experimental data for powder samples showed about 2.5 to about 4.0% n-propanol and about 2.5 to about 3% water. Its PXRD pattern is very similar to its isomorphs F, G, H, M and N. Like F and G, the powder samples had a dehydration/desolvation heat of absorption (endotherm) at 115-125 ℃.

Form J was prepared as follows: dissolving azithromycin in 4 volumes of n-propanol at a temperature of 25-55 ℃; adding about 6-7 volumes of water at room temperature, and continuing to stir the slurry for 0.5-2 hours; solid azithromycin form J was collected by filtration and dried.

And (3) type K: PXRD patterns for form K were seen after annealing (aneal) for 3 hours at 95 ℃ in a mixture of azithromycin form a and microcrystalline wax. It is a low hydrate of type a, a metastable high temperature form.

L type: this form was observed only after heating form a dihydrate. In a variable temperature powder X-ray diffraction (VT-PXRD) experiment, a new powder X-ray diffraction pattern appeared when form A was heated to about 90 deg.C. The new form is designated form L and is a low hydrate of form a, since form a loses about 2.5 wt.% water at 90 ℃ as evidenced by TGA, and thus is equivalent to conversion to the monohydrate. Upon cooling to ambient temperature, form L rapidly reverts to form a.

M type: form M, isolated from an isopropanol/water slurry, combines water and isopropanol. Its PXRD pattern and ssNMR spectrum are very similar to family I isoforms, indicating that it belongs to family I. Similar to the known crystal structure of family I isomorphs, the M-type single crystal structure will be a monohydrate/hemi-isopropanolate. The dehydration/desolvation temperature of form M was about 115-125 ℃.

Form M can be prepared by: dissolving azithromycin in 2-3 volumes of isopropyl alcohol (IPA) at 40-50 deg.C; cooling the solution to below 15 ℃, preferably below 10 ℃, more preferably about 5 ℃, adding 2-4 volumes of cold water at about 5 ℃ to precipitate; m-type seed crystals can be added at the beginning of crystallization; stirring the slurry for less than about 5 hours, preferably less than about 3 hours, more preferably less than about 1 hour, and most preferably about 30 minutes or less, and filtering to collect the solids; the solids can be resuspended in isopropanol. This process provides form M substantially free of azithromycin dihydrate.

And (2) N type: the N-type crystals isolated from the water/ethanol/isopropanol slurry of form a may contain variable amounts of crystallization solvent and water. Its water content varies from about 3.4 to about 5.3% by weight. GC gas-on-liquid analysis (Headspace) revealed variable ethanol and isopropanol contents. The total solvent content of the N-type samples is typically less than about 5%, depending on the conditions of preparation and drying. The PXRD pattern for type N is similar to F, G, H, J and type M for family I isoforms. The dehydration/desolvation endotherm for the N-type samples may be wider and may vary between 110-130 ℃.

Azithromycin form N can be prepared by: azithromycin is recrystallized from a mixture of azithromycin lattice-binding organic solvents, such as ethanol, isopropanol, n-propanol, acetone, acetonitrile, etc.: heating the solvent mixture to 45-60 ℃, adding azithromycin to the heated solvent mixture for a total of about 4 volumes; after dissolution, adding 1-3 volume of water, and continuously stirring at 45-60 ℃; the N-type azithromycin precipitates out as a white solid; allowing the slurry to cool to ambient temperature while stirring; solid azithromycin form N is isolated by filtration and dried.

And (3) O type: this crystal form was a semi-aqueous half-n-butanol solvate of azithromycin free base as can be seen from the single crystal structure data (Table 8A). It is isolated from a solution of azithromycin in n-butanol, which is diffused with an anti-solvent (anti). The O-form crystal structure is isomorphic with the family I crystal form.

Azithromycin is completely dissolved in n-butanol. Addition of an anti-solvent such as hexane, water, IPE or other non-solvent causes precipitation of form O by diffusion.

P type: this is a proposed crystalline form which is a hemipentanal solvate of azithromycin free base. It may be isolated from a solution of azithromycin in n-pentanol diffused with an anti-solvent. The P-type crystal structure is isomorphic with the family I crystal form.

The P-type azithromycin may be prepared as follows: completely dissolving azithromycin in n-amyl alcohol; addition of an anti-solvent such as hexane, water, isopropyl ether (IPE) or other non-solvent, diffusion causes P-type to precipitate out.

Type Q: form Q exhibits a unique powder X-ray diffraction pattern. It contains about 4% water and about 4.5% THF and is a monohydrated hemithf solvate. The primary dehydration/desolvation temperature is from about 80 to about 110 ℃.

Azithromycin dihydrate was dissolved in 6 volumes of THF and 2 volumes of water were added. The solution was evaporated to dryness at ambient conditions to give crystalline form Q.

R type: this crystalline form is prepared by: adding amorphous azithromycin to 2.5 volumes of tert-butyl methyl ether (MTBE); the resulting thick white suspension was stirred for 3 days under ambient conditions; the solid was collected by vacuum filtration and air dried. The resulting bulk (bulk) azithromycin form R has a theoretical water content of 2.1% by weight and a theoretical methyl t-butyl ether content of 10.3% by weight.

Because of their structural similarity, polymorphs have a tendency to form a mixture of crystalline forms of the same family, sometimes referred to as "mixed crystals" or "crystalline solid solutions". Form N is such a solid crystalline solution that is found to be a mixture of family I polymorphs by virtue of solvent composition and solid state NMR data.

Both family I and II isoforms are hydrates and/or solvates of azithromycin. Under specific conditions, the solvent molecules within the cavities (caivies) have a tendency to exchange between the solvent and water. Thus, the solvent/water content of the isomorphs may vary to some extent.

The family I crystal form of the polymorph is more stable than form a when heated. F. G, H, J, M and the initial dehydration temperature of type N is 110-125 deg.C, which is higher than the initial dehydration temperature of type A from about 90 to about 110 deg.C, and type A is solid-state transformed into type L at about 90 deg.C.

Amorphous azithromycin: all crystalline forms of azithromycin contain water or solvent or both water and solvent. When the water and solvent are removed from the crystalline solid, the azithromycin becomes amorphous. Amorphous solids have the advantage of a high initial dissolution rate.

The starting material for the various crystal form analyses in the following examples is azithromycin dihydrate, unless otherwise noted. Other forms of azithromycin may be used, such as amorphous azithromycin or other non-dihydrate crystalline forms of azithromycin.

Examples

Example 1: preparation of form D

Form D was prepared as follows: azithromycin dihydrate is slurried in cyclohexane at elevated temperature, e.g., 25-50 ℃, for 2-4 days; the crystalline solid of form D was collected by filtration and dried.

Example 2: preparation of form F

2A: azithromycin dihydrate was slowly added to a volume of warm ethanol at about 70 c and stirred at 65 to 70 c until completely dissolved. 1-2% by weight of type F seeds may be introduced to promote crystallization. The solution was gradually cooled to 2-5 ℃ and a volume of chilled water (chilled water) was added. The crystalline solid was collected by vacuum filtration shortly after addition of water (preferably less than 30 minutes).

2B: azithromycin dihydrate was slowly added to a volume of warm ethanol at about 70 c and stirred at 65 to 70 c until completely dissolved. 1-2% by weight of type F seeds may be introduced to promote crystallization. The solution was gradually cooled to 2-5 ℃ and the volume of ethanol was reduced by vacuum distillation. After stirring for up to 2 hours, the crystalline solid was collected by vacuum filtration. The crystals are separated to provide substantially pure azithromycin form F, azithromycin form F substantially free of azithromycin form G, and azithromycin form F substantially free of azithromycin dihydrate.

Example 3: preparation of form G

The reaction vessel was charged with azithromycin form a. In a separate container, 1.5 volumes of methanol and 1.5 volumes of water were mixed. The solvent mixture is added to the reaction vessel containing azithromycin form a. The slurry was stirred while heating to 50 ℃ for about 5 hours. The heating was discontinued and the slurry was allowed to cool while stirring to ambient temperature. Azithromycin form G was collected by filtration and air dried for about 30 minutes. The collected azithromycin form G was further dried in a vacuum oven at 45 ℃. This process results in substantially pure azithromycin form G and azithromycin form G substantially free of azithromycin dihydrate.

Example 4: preparation of form J

Form J was prepared as follows: dissolving azithromycin in 4 volumes of n-propanol at a temperature of about 25 ℃; water (6.7 volumes) was added and the slurry was stirred for an additional 1 hour and then cooled to about 0 ℃; solid azithromycin form J was collected by filtration and dried.

Example 5: preparation of form M substantially free of azithromycin dihydrate

5A: azithromycin dihydrate is completely dissolved in 2 volumes of warmed isopropanol at 40-50 ℃. Type M seeds may optionally be introduced to promote crystallization. The solution was then cooled to 0-5 ℃,4 volumes of cooling water were added as anti-solvent, and the solid was collected by vacuum filtration. The solid was resuspended in 1 volume of isopropanol at 40-45 ℃ for 3-5 hours and then cooled to 0-5 ℃. The crystalline solid was collected by vacuum filtration shortly after addition of water (about 15 minutes). The solid was resuspended in 0.5 to 1 volume of isopropanol at 25-40 ℃, cooled to about 5 ℃, and then filtered to collect form M solid.

5B: azithromycin dihydrate (1940 grams) was completely dissolved in 2 volumes of warmed (45 ℃) warmed isopropanol. The resulting clear solution was filtered through an inner diameter (inline)0.2 μm filter into a clean flask. The temperature was maintained at 45 ℃ and the solution was seeded with M-type crystals. 7.8L of cooling water was added over 8 minutes. The solution was cooled to 5 ℃ and was noticed to become a thick slurry. The solid was isolated by vacuum filtration and transferred to a clean flask. Crystalline azithromycin was slurried in 1 volume of isopropanol while warming to 35 ℃. The slurry was then cooled to 5 ℃ for 30 minutes and the solid crystalline product was filtered off.

These processes result in substantially pure form M azithromycin, form M azithromycin that is substantially free of form G azithromycin, and form M azithromycin that is substantially free of azithromycin dihydrate.

Example 6: preparation of N-type

2 volumes of ethanol and 2 volumes of isopropanol were added to the reaction vessel and heated to 50 ℃. Azithromycin form a was added to the hot ethanol/isopropanol mixture while stirring to give a clear solution. The reaction vessel was charged with 2 volumes of distilled water (ambient temperature). Stirring was continued at 50 ℃ and after about 1 hour solid azithromycin form N precipitated out. The heating was discontinued for 5 hours after the addition of water. The slurry was allowed to cool to ambient temperature. The precipitated azithromycin of N-type was collected by filtration and dried in a vacuum oven at 45 ℃ for 4 hours.

Example 7: preparation of amorphous azithromycin

Azithromycin in crystalline form a was heated to 110-. The amorphous solid was collected, stored and added with desiccant as needed.

Example 8: preparation of form H

Azithromycin dihydrate or other crystalline form is dissolved in 6 volumes of propylene glycol. To the resulting azithromycin in propylene glycol solution was added 2 volumes of water and a precipitate formed. The slurry was stirred for 24 hours, the solid filtered and air dried at ambient temperature to give crystalline form H.

Example 9: preparation of form Q

The crystalline powder is prepared by: 500mg of azithromycin form A are dissolved in 2ml of THF; to the clear colorless solution was added 1ml of water at room temperature; when the solution became cloudy, another 1ml of THF was added to completely dissolve the azithromycin and the solution was stirred at ambient temperature; the solvent was evaporated over 7 days and the dried solid was collected for characterization.

Example 10: powder X-ray diffraction analysis

Powder patterns were collected using a Bruker D5000 diffractometer (Madison, Wisconsin) equipped with a copper radiation source (copper radiation), fixed slits (1.0, 1.0, 0.6mm) and a Kevex solid state detector. Data was collected over a 2 theta range of 3.0 to 40.0 degrees, step 0.04 degrees, step 1.0 second. The results are summarized in table 9.

Figure 2 shows the experimental PXRD diffraction pattern for azithromycin form a.

Figure 6 shows the experimental PXRD diffraction pattern for form D azithromycin.

Figure 10 shows the experimental PXRD diffraction pattern for azithromycin form F.

Figure 13 shows the experimental PXRD diffraction pattern for azithromycin form G.

Figure 16 shows the experimental PXRD diffraction pattern for azithromycin form J.

Figure 18 shows the experimental PXRD diffraction pattern for azithromycin form M.

Figure 19 shows the experimental PXRD diffraction pattern for azithromycin form N.

Figure 20 shows the experimental PXRD diffraction pattern for amorphous azithromycin.

Figure 30 shows the experimental PXRD diffraction pattern for azithromycin form Q.

Figure 31 shows the experimental PXRD diffraction pattern for azithromycin form R.

The experimental variability (experimental variability) from sample to sample was about ± 0.2 ° 2 θ, the same variation was observed between data calculated from single crystal structure powder and experimental data. Detailed analysis showed that: isoforms in family I can be identified by PXRD and the characteristic peak set is given in table 9.

Table 9: azithromycin powder X-ray diffraction peak with 2 theta of 0.2

A	D	F	G	J	M	N	Q
								7.2	3.9	5.7	5.0	5.0	5.0	6.2	5.7
7.9	7.3	6.2	5.8	5.7	5.6	7.3	6.1
								9.3	7.7	7.4	6.2	6.2	6.2	7.8	6.8
9.9	10.1	7.8	7.4	7.3	7.3	9.8	8.4
								11.2	10.6	8.9	7.9	7.8	7.8	11.2	9.5
12.0	11.5	9.8	9.8	8.2	8.2	11.9	10.6

12.7	12.3	10.3	10.2	9.7	9.8	12.5	11.2
								13.0	12.8	11.2	10.8	10.3	10.2	14.0	11.5
14.0	13.6	11.5	11.2	11.2	11.2	14.3	12.4
								15.6	14.5	11.9	11.6	11.4	11.9	14.7	12.7
16.0	15.4	12.2	12.0	11.9	12.2	15.3	13.4
								16.4	15.6	12.5	12.5	12.3	12.5	15.7	13.6
16.8	16.9	13.9	13.3	12.5	14.0	16.1	14.1
								17.5	18.3	14.3	14.0	13.9	14.6	16.6	14.4
18.2	19.0	14.7	14.4	14.2	15.3	17.1	14.9
								18.7	19.9	14.8	14.6	14.6	15.9	17.4	16.3
19.1	20.8	15.3	14.9	15.3	16.6	18.5	17.2
								19.8	21.4	15.7	15.3	15.7	17.1	19.0	18.2
20.5	21.6	16.2	15.7	16.0	17.5	19.6	19.0
								20.9	22.0	16.6	16.3	16.6	18.4	20.0	19.5
21.2	23.0	17.1	16.6	17.0	18.5	20.4	19.8
								21.6	23.3	17.2	17.2	17.2	19.1	21.0	20.2
21.8		17.7	17.4	17.5	19.6	21.8	20.5
								24.0		18.0	17.8	18.1	20.0	22.5	21.1
		18.5	18.1	18.5	20.4	23.5	21.6
										19.0	18.6	19.0	20.9		21.9
		19.6	19.0	19.7	21.7		22.2
										20.0	19.6	20.0	22.5		23.6
		20.5	20.0	20.4	23.2		25.1
										21.0	20.5	20.9	23.6
		21.7	21.1	21.7
										22.0	21.8	22.4
		22.4	22.5	22.6
										22.6	23.5	23.3
		23.1		23.5
										23.5
A	D	F	G	J	M	N	Q

The underlined peaks are characteristic peaks of A, D, family I and type Q.

The italicized and underlined peaks are a unique set of peaks within the family I isoform.

Family I isoforms share the following common features: diffraction peaks were 6.2, 11.2, 21.0 + -0.1 and 22.5 + -0.1 degrees 2 theta. Each isomorph shows the following representative set of diffraction peaks, each set having a characteristic spacing between peaks.

The reported diffraction peak positions are accurate to 2 theta angles ± 0.2 degrees.

A representative PXRD pattern for form a is shown in fig. 2. Form a shows peaks at 9.3, 13.0, and 18.7 degrees 2 θ.

A representative PXRD pattern for form D is shown in fig. 6. Form D shows peaks at 3.9, 10.1, 10.6, and 21.4 degrees 2 θ.

A representative PXRD pattern for form F is shown in fig. 10. Form F shows characteristic peaks and three groups of peaks for family I, with group 1 having 2 theta of 11.2 and 11.5, group 2 having 2 theta of 13.9, 14.3, 14.7 and 14.8, and group 3 having 2 theta of 16.2, 16.6, 17.1, 17.2 and 17.7.

A representative PXRD pattern for type G is shown in fig. 13. Form G shows characteristic peaks and three groups of peaks for family I, with group 1 having 2 theta of 11.2 and 11.6, group 2 having 2 theta of 14.0, 14.4, 14.6 and 14.9, and group 3 having 2 theta of 16.3, 16.6, 17.2, 17.4 and 17.8.

A representative PXRD pattern for form J is shown in fig. 16. Form J shows characteristic peaks and three groups of peaks for family I, with group 1 having 2 theta of 11.2 and 11.4, group 2 having 2 theta of 13.9, 14.2 and 14.6, and group 3 having 2 theta of 16.0, 16.6, 17.0, 17.2 and 17.5.

A representative PXRD pattern for type M is shown in fig. 18. Form M shows characteristic peaks and three groups of peaks for family I, with group 1 having a 2 theta of 11.2, group 2 having 2 theta of 14.0 and 14.6, and group 3 having 2 theta of 15.9, 16.6, 17.1 and 17.5.

A representative PXRD pattern for type N is shown in fig. 10. Type N shows characteristic peaks of family I. The peak group of N-type is similar to F, G, J and M-type, with group 1 having a 2 theta of 11.2 to 11.6, group 2 having a 2 theta of 13.9 to 15.0, and group 3 having a 2 theta of 15.9 to 17.9, and the position, intensity and width of the peaks can vary slightly due to the mixing of variable proportions of family I isoforms.

A representative PXRD pattern for form Q is shown in fig. 30. Form Q shows peaks at 6.8, 8.4 and 20.2 degrees 2 θ.

A representative PXRD pattern for form R is shown in fig. 31.

Example 11: single crystal X-ray analysis

Data were collected at room temperature using a Bruker X-ray diffractometer equipped with a copper radiation source and graphite monochromators (graphite monochromators). The (solve) structure was solved using direct method (direct method). The SHELXTL computer library provided by Bruker AXS, inc. facilitates all necessary crystallographic calculations and molecular display (SHELXTL)^TM Reference Manual，Version 5.1，Bruker AXS，Madison，Wisconsin，USA(1997))。

Example 12: calculation of PXRD patterns from Single Crystal data

To compare the results between single crystals and powder samples, a calculated powder pattern can be derived from the single crystal results. This calculation is performed using XFOG and XPOW computer programs that are part of the SHELXTL computer library. The calculated powder pattern was compared with the experimental powder pattern to confirm whether the powder sample corresponds to the specified single crystal structure (table 9A). This process was carried out for forms A, D, F, G and J of azithromycin.

Figure 1 shows the calculated PXRD diffraction pattern for azithromycin form a.

Figure 5 shows the calculated PXRD diffraction pattern for azithromycin form D.

Figure 9 shows the calculated PXRD diffraction pattern for azithromycin form F.

Figure 12 shows the calculated PXRD diffraction pattern for azithromycin form G.

Figure 15 shows the calculated PXRD diffraction pattern for azithromycin form J.

FIGS. 3, 7, 11, 14 and 17 show overlapping powder X-ray diffraction patterns of A, D, F, G and type J, respectively. The lower pattern corresponds to the calculated powder pattern (from the single crystal results) and the upper pattern corresponds to the representative experimental powder pattern. The match between the two patterns illustrates the consistency between the powder sample and the corresponding single crystal structure.

Table 9A: calculation and experimental PXRD peak of family I isomorphs

F calculation	F experiment	G calculation	G experiment	J calculation	J experiment	M experiment
									5.2	5.0
		5.7	5.8	5.8	5.7	5.6
							6.3	6.2	6.2	6.2	6.3	6.2	6.2
7.4	7.4	7.5	7.4	7.4	7.3	7.3
							7.9	7.8	7.9	7.9	7.9	7.8	7.8
8.8	8.9	8.9	9.3	8.3	8.2	8.2
							9.9	9.8	9.9	9.9	9.8	9.7	9.8
10.3	10.3		10.2	10.4	10.3	10.2
							10.9		10.9	10.8
11.3	11.2	11.3	11.2	11.2	11.2	11.2
							11.5	11.4	11.6	11.6	11.4	11.4	missing
12.0	11.9	12.0	11.9	12.0	11.9	11.9
							12.3	12.2	12.3		12.3	12.3	12.2
12.6	12.5	12.5	12.5	12.0	12.5	12.5
							14.0	14.0	13.4	13.3	14.0	13.9	14.0
14.3	14.3	14.1	14.0	14.2	14.2	missing
									14.4	14.4
14.7	14.7	14.7	14.6	14.7	14.6	14.6
							14.9	14.8	14.9	14.9	14.8
15.4	15.3	15.4	15.3	15.3	15.3	15.3
							15.8	15.7	15.7	15.7	15.8	15.7	15.9
16.2	16.2	16.3	16.3	16.0	16.0	missing
							16.6	16.6	16.6	16.6	16.7	16.6	16.6
17.1	17.2	17.1		17.1	17.0	17.1
							17.3	17.3	17.3	17.2	17.4	17.2	missing
17.5	17.4	17.5	17.4	17.6	17.5	17.5
							17.7	17.7	17.9	17.8	17.9
18.0	18.0	18.1	18.1	18.2	18.1	18.4
							18.6	18.5	18.7	18.7	18.5	18.5	18.5
19.1	19.0	19.1	19.0	19.1	19.0	19.1
							19.7	19.6	19.6	19.5	19.8	19.7	19.6
20.0	20.0	20.0	20.0	20.1	20.0	20.0
							20.5	20.4	20.6	20.5	20.5	20.4	20.4
21.1	21.0	21.2	21.0	20.8	20.9	20.9
							21.8	21.7		21.6	21.6	21.7	21.7
22.1	22.0	21.8	21.8	21.8
							22.5	22.4	22.3	22.2	22.5	22.4	22.5
22.7	22.6	22.5	22.5	22.8	22.6
							23.1	23.1	22.9		23.4	23.3	23.2
23.6	23.5	23.5	23.5	23.7	23.5	23.6

Example 13: solid state NMR analysis

Solid state NMR analysis:

all of¹³The C solid state NMR spectra were collected on an 11.75T spectrometer (Bruker Biospin, Inc., Billerica, Mass.) and corresponded to 125MHz¹³And C, frequency. Spectra were collected using a cross-polarization magic angle spinning (CPMAS) probe operated at ambient temperature and pressure. Depending on the number of samples analysed, 300mg and 75mg samples were accommodated using 7mm BL or 4mm BLBruker probes, respectively, with maximum speeds of 7kHz and 15kHz, respectively. The data was processed using a line broadening function of 5.0 Hz. Proton decoupling was performed at 65kHz and 100kHz using 7mm and 4mm probes, respectively. Sufficient amount of the harvest was averaged to obtain a signal to noise ratio suitable for all peaks. Typically, 600 scans are shown for a cycle of 3.0 seconds, corresponding to a total acquisition time of about 30 minutes. The magic angle was adjusted using KBr powder as per standard NMR vendor practice. Spectra were referenced against 17.3ppm Hexamethylbenzene (HMB) methyl resonance or 29.5ppm Adamantane (ADM) high magnetic field resonance. For the same spectrum introduced as ADM, the chemical shift of the spectrum introduced as HMB shows a downward shift of 0.08ppm of all peaks. The spectral window comprises at least a spectral region of 190 to 0 ppm. The results are summarized in table 10. The ss NMR spectra of M, H and R are referred to as ADM. A. The ss NMR spectra of D, G, F, J and N are referenced as HMB. The H and R forms spin at a rate of 15 kHz.

Table 10: process for preparing azithromycin¹³css-NMR chemical shifts (+ -0.2 ppm)

A	D	G	F	J	M	N	H	R
									178.1	178.1	179.5 *	179.5	179.6	179.6	179.6	179.5	177.9
104.1	103.9	105.5	178.6	178.4	105.6	178.7	178.7	104.6
									98.4	95.1	103.5	105.5	105.5	103.4	105.6	105.4	103.6
84.6	84.2	95.0	103.4	103.4	94.9	103.6	103.2	95.3
									82.6	79.4	86.2	94.9	95.0	86.7	95.0	95.0	85.4
79.3	78.9	83.1	86.4	86.4	82.9	86.5	86.4	84.0
									78.3	75.7	78.9	83.0	82.9	79.3	83.1	82.7	79.4
75.6	74.6	78.2	79.1	79.2	78.1	79.0	79.2	79.0
									74.7	74.0	77.6	78.1	78.1	77.0	77.9	78.3	75.6
73.9	72.9	76.4	77.9	76.8	76.7	76.5	78.0	74.5
									73.5	71.9	75.7	76.5	76.2	74.7	74.8	76.4	73.9
70.8	71.0	74.7	74.7	74.7	74.2	74.2	74.7	73.9
									68.0	69.4	74.3	74.1	74.1**	71.3	73.6	74.1	72.9
66.2	67.8	73.5	73.5	72.0	69.2	71.5	73.5	71.8
									63.8	65.7	71.3	71.4	71.3	68.6	69.2	73.1	71.0
63.2	64.7	69.1	69.1	69.2	67.3	68.7	71.2	69.1
									52.2	49.2	68.8	68.6	68.6	66.2	67.3	69.1	67.5

44.3	45.8	67.4	67.3	67.3**	65.5	66.2	68.4	65.6
									42.6	43.1	65.9	66.1	66.2**	63.8	65.7	67.3	64.5
41.7	40.6	65.2	65.6	65.5**	63.3	63.7	66.9	49.4
									39.1	37.1	64.0	63.6	63.7	50.0	58.1	66.1	45.7
35.4	36.4	63.3	58.0	50.0	47.1	50.1	65.5*	42.9
									34.6	29.6	50.0	50.0	46.9	45.9	47.1	63.7*	41.6
26.9	29.3	46.9	47.0	45.9	44.7	46.0	49.9	40.4
									26.3	28.0	46.0	45.9	44.7	43.8	44.8	46.8	37.0
23.7	27.7	44.5	44.7	43.7	41.9	43.8	45.9	36.2
									23.3	22.1	43.7	43.7	41.6	41.1	41.5	44.5	29.4
21.7	21.1	41.5	41.5	41.0	37.4	41.1	43.8*	29.0
									19.5	18.6	40.8	41.1	37.1	36.2	37.3	41.7	28.2
17.5	16.7	37.5	37.3	36.5**	33.6	36.5	40.9	27.4
									15.9	16.1	36.5	36.4	35.4**	30.1	33.7	37.1	21.4
13.2	10.6	33.6	33.6	33.5	28.1	30.4	36.3	20.8
									11.3	9.0	30.0	30.3	30.4	27.2	28.1	33.7	18.7
7.2	8.6	27.9	28.0	28.0	26.0	27.2	33.3	16.5
											27.3	27.1	27.1	23.2	26.0	30.5*	16.1
		23.1	23.2	25.2	22.8	23.2	27.9	15.7
											22.5	22.6	23.2	22.5	22.6	27.1	10.3
		21.9	21.9	22.5**	21.8	22.0	23.1	9.6

The chemical shifts marked in bold and underlined are representative peaks or groups of peaks for each crystalline form. The italicized chemical shifts are solvent peaks, possibly broad and variable (± 0.4 ppm). Chemical shifts marked with a single star number may show < 0.3ppm splitting. Chemical shifts marked with double asterisks may show a difference of ± 0.3 ppm.

Table 10 (next): process for preparing azithromycin¹³css-NMR chemical shifts (+ -0.2 ppm)

A	D	G	F	J	M	N	H	R
											20.9	20.8	21.9**	20.2	20.8	22.6	8.9
		20.2	20.4	20.7	18.9	19.0	22.3	8.6
											18.8	18.9	18.9	17.4	16.9	21.9
		17.0	16.8	16.8	16.3	15.8	20.7
											16.0	17.2	15.6**	15.5	12.2	20.3
		12.2	15.7	12.1	12.1	9.9	18.8
											10.4	12.2	11.5	10.3	9.4	17.1
		9.9	10.1	12.1	9.6	7.9	16.6
											9.3	9.8	10.0	9.3	6.6	15.8

		7.6	9.3	9.3	7.7		15.4
											6.5	7.9	8.1	7.1		12.0
			6.6	6.8 **			9.9
																9.1
							7.9
																7.0

The bold and underlined chemical shifts are representative peaks or groups of peaks for each crystalline form. The italicized labeled chemical shifts are solvent peaks, possibly broad and variable (± 0.4 ppm). Chemical shifts marked with a single star number may show < 0.3ppm splitting. Chemical shifts marked with double asterisks may show a difference of ± 0.3 ppm.

The reported chemical shifts are accurate to. + -. 0.2ppm unless otherwise indicated.

Representatives of form A¹³The C ssNMR spectrum is shown in FIG. 21. Form A showed a peak at 178.1ppm and group peaks at 104.1, 98.4, 84.6, 26.9, 13.2, 11.3 and 7.2 ppm.

Representatives of form D¹³The C ssNMR spectrum is shown in FIG. 22. Form D showed the highest chemical shift peak at 178.1ppm and chemical shift peaks at 103.9, 95.1, 84.2, 10.6, 9.0 and 8.6 ppm.

Representatives of form F¹³The C ssNMR spectrum is shown in FIG. 23. Form F has two chemical shift peaks at approximately 179.1 + -2 ppm, which are 179.5ppm and 178.6ppm, a set of 5 peaks at 10.1, 9.8, 9.3, 7.9, and 6.6ppm, and ethanol peaks at 58.0 + -0.5 ppm and 17.2 + -0.5 ppm. The solvent peak may be broad and relatively weak in intensity.

Representatives of form G¹³The C ssNMR spectrum is shown in FIG. 24. Form G has the highest chemical shift peak of 179.5ppm, is unimodal, has a possible split of < 0.3ppm, and also has a set of 5 peaks at 10.4, 9.9, 9.3, 7.6 and 6.5 ppm.

Representatives of form J¹³The C ssNMR spectrum is shown in FIG. 25. Form J has two chemical shift peaks at approximately 179.1 + -2 ppm, which are 179.6ppm and 178.4ppm, a set of 4 peaks at 10.0, 9.3, 8.1 and 6.8ppm, and n-propanol peaks at 11.5 + -0.5 ppm and 25.2 + -0.5 ppm. The solvent peak may be broad and relatively weak in intensity.

Representatives of type M¹³The C ssNMR spectrum is shown in FIG. 26. Form M has a chemical shift peak at about 179. + -. 1ppm, which is 179.6ppm, two at 41.9 and 16.3ppmPeaks, with a set of 5 peaks at 10.3, 9.6, 9.3, 7.7 and 7.1ppm and an isopropanol peak at 26.0 ± 0.5 ppm. The solvent peak may be broad and relatively weak in intensity.

Representatives of the N type¹³The C ssNMR spectrum is shown in FIG. 27. Chemical shifts of the N-type are shown as combinations of family I isoforms. Since the N-type crystalline solid solution is mixed with isomorphs in a variable ratio, chemical shifts and relative intensities and widths of peaks may be different from each other.

Representatives of the amorphous form¹³The C ssNMR spectrum is shown in FIG. 28. Amorphous azithromycin exhibits a broad chemical shift. The positions of the characteristic chemical shift peaks are 179 and 11. + -. 0.5 ppm.

Table 10 gives a list of ssNMR peaks observed for A, D, F, G, H, J, M, N and azithromycin form R.

Example 14: NMR analysis of dosage forms

To prove that¹³The ability to identify the crystal form of azithromycin contained in a pharmaceutical dosage form by C ssNMR, preparing azithromycin coated tablets containing form G of azithromycin by means of¹³C ssNMR analysis. The tablets were wet granulated and compressed on F-Press (Manesty, Liverpool, UK) using a 0.262 "x 0.531" format. Tablets were formulated containing 250mg of azithromycin form G, with a total tablet weight of 450mg, the formulation given below. The tablets were uniformly coated with pink Opadry II  (lactose monohydrate, hydroxypropylmethyl cellulose, titanium dioxide, a mixture of 30 red and triacetin for pharmaceutical and cosmetic use) (Colorcon, West Point, PA).

Raw materials	Percentage of	Batches (g)
			Azithromycin type G	58.23	174.69
Pregelatinized corn starch	6.00	18.00
			Anhydrous dicalcium phosphate (anhydrous dicalcium phosphate)	30.85	92.55
Croscarmellose sodium (sodium croscarmelose)	2.00	6.00
			Magnesium stearate containing 10% sodium lauryl sulfate	2.92	8.76
Total of	100.00	300.00

The coated tablets were lightly crushed and the crushed samples were packed in a solid state rotor (solid state rotor) with a packing tool (packing tool) without containing¹³And C, background. The sample analysis was performed under the conditions described in example 13.

Representative of tablets containing azithromycin form G¹³The C ssNMR spectrum is shown in FIG. 29.

Example 15: antimicrobial activityProperty of (2)

The activity of the crystalline forms of the invention against bacterial and protozoan pathogens is demonstrated by the ability of the compounds to inhibit the growth of defined human pathogens (assay I) or animal pathogens (assays II and III).

Assay I

The following assay I, using conventional methods and interpretation criteria, is designed to provide a direction for chemical modification that can generate compounds that circumvent the defined mechanism of macrolide resistance. In assay I, a panel of bacterial strains (a panel of bacterial strains) was pooled, including various target pathogen species, including representatives of macrolide resistance mechanisms that have been identified. The chemical structure/activity relationships with respect to potency (potency), activity spectrum (spectrum of activity) and structural elements (structures) or modifications (modification) can be determined using this group of strains, which may be necessary to avoid the resistance mechanism. The bacterial pathogens comprising the screening groups are shown in the table below. In many cases, macrolide-susceptible parent strains and macrolide-tolerant strains derived therefrom are useful to provide a more accurate assessment of the ability of compounds to circumvent resistance mechanisms. Strains containing the gene designated ermA/ermB/ermC are resistant to macrolide, lincosamide (lincosamide) and streptogramin B antibiotics, since the 23S rRNA molecule is modified (methylated) by the Erm methylase, thus generally preventing the binding of all three structural species. Two types of macrolide effluents (efflux) have been described: msrA encodes an efflux system component in staphylococci that prevents the entry of macrolides and streptogramins, while mefA/E encodes a transmembrane protein that appears to only shed macrolides. Phosphorylation of the 2' -hydroxyl group (mph) or cleavage of the macrolide (esterase) can both cause and mediate inactivation of macrolide antibiotics. Strains can be identified using conventional Polymerase Chain Reaction (PCR) techniques and/or sequencing of drug resistance determinants. The use of PCR technology in this application is described in J.Sutcliffe et al, "Detection of Erythromycin-resist primers By PCR", antibiotic Agents and Chemothersapy, 40(11), 2562, 2566 (1996). The assay was carried out in a microtiter dish, the basis for the interpretation beingPerformance Standards for Antimicrobial Disk Susceptibility Tests- Sixth Edition；Approved StandardInstructions published by The National Committee for Clinical Laboratory Standards (NCCLS); strains were compared using the Minimum Inhibitory Concentration (MIC). The crystalline compound was first dissolved in dimethyl sulfoxide (DMSO) as a 40mg/ml stock solution.

Strain nomenclature	Mechanism of macrolide resistance
		Staphylococcus aureus 1116	Sensitive matrix
Staphylococcus aureus 1117	ErmB
		Staphylococcus aureus 0052	Sensitive matrix
Staphylococcus aureus 1120	ErmC
		Staphylococcus aureus 1032	msrA, mph, esterase
Hemolytic staphylococcus 1006	msrA，mph
		Streptococcus pyogenes 0203	Sensitive matrix
Streptococcus pyogenes 1079	ErmB
		Streptococcus pyogenes 1062	Sensitive matrix
Streptococcus pyogenes 1061	ErmB
		Streptococcus pyogenes 1064	ErmB
Streptococcus agalactiae 1024	Sensitive matrix
		Streptococcus agalactiae 1023	ErmB
Streptococcus pneumoniae 1016	Sensitivity of the composition

Streptococcus pneumoniae 1046	ErmB
		Streptococcus pneumoniae 1095	ErmB
Streptococcus pneumoniae 1175	MefE
		Streptococcus pneumoniae 0085	Sensitivity of the composition
Haemophilus influenzae 0131	Sensitivity of the composition
		Moraxella catarrhalis 0040	Sensitivity of the composition
Moraxella catarrhalis 1055	Intermediate resistance to erythromycin
		Escherichia coli 0266	Sensitivity of the composition

Assay II was used to test the activity against Pasteurella multocida and assay III was used to test the activity against Pasteurella haemolytica.

Assay II

The assay is based on the microtiter format (m)icroliter format). A single colony of pasteurella multocida (strain 59a067) was inoculated into 5ml of heart brain infusion (BHI) broth. Test compounds were prepared by solubilizing 1mg of the compound in 125. mu.l of dimethyl sulfoxide (DMSO). Dilutions of test compounds were prepared using uninoculated BHI broth. The concentration of test compound used ranged from 200. mu.g/ml to 0.098. mu.g/ml, with two-fold serial dilutions. BHI inoculated with Pasteurella multocida was diluted with uninoculated BHI broth to give 10⁴Cells/200. mu.l suspension. The BHI cell suspension was mixed with each serial dilution of test compound and incubated at 37 ℃ for 18 hours. The Minimum Inhibitory Concentration (MIC) is equal to the concentration at which the compound exhibits 100% inhibition of the growth of pasteurella multocida, as determined by comparison with an uninoculated control.

Assay III

The assay was based on the agar dilution method using a stees Replicator. Between 2 and 5 colonies isolated from agar plates were inoculated in BHI broth and incubated overnight at 37 ℃ with shaking (200 rpm). The next morning, 300. mu.l of a well-grown Pasteurella haemolytica (P.haemolytica) preculture was inoculated in 3ml of fresh BHI broth and incubated at 37 ℃ with shaking (200 rpm). Appropriate amounts of test compounds were dissolved in ethanol to prepare a series of two-fold serial dilutions. 2ml of each dilution series was mixed with 18ml of melted BHI agar and allowed to solidify. When the inoculated culture of Pasteurella haemolytica reached a standard density of 0.5McFarland, approximately 5. mu.l of the culture of Pasteurella haemolytica was inoculated using a Steers Replicator onto BHI agar plates containing various concentrations of the test compound and incubated at 37 ℃ for 18 hours. The initial concentration range for the test compounds was 100-200. mu.g/ml. The MIC was equal to the concentration of test compound showing 100% inhibition of the growth of pasteurella haemolytica, as determined by comparison with the uninoculated control.

The in vivo activity of the crystalline forms of the invention may be determined by routine animal protection studies well known to those skilled in the art, typically in mice.

After mice arrived, they were distributed into cages (10 per cage) and acclimated for a minimum of 48 hours prior to use. Intraperitoneal inoculation of 3X 10 animals³CFU/ml bacterial slurry (P.multocida strain 59A 006). Each experiment had at least 3 non-dosed control groups, including one group infected with 0.1X challenge dose (challenge dose) and two groups infected with 1X challenge dose; the data set may also be attacked using 10X. In general, all mice in a given study can be challenged within 30-90 minutes, particularly when given a challenge using a reciprocating syringe (e.g., a Cornwalls syringe). 30 minutes after the start of challenge, the first compound treatment was given. If all animals have not been challenged at the end of 30 minutes, a second person may be required to begin compound administration. The route of administration is subcutaneous or oral. Subcutaneous administration is on the flaccid skin behind the neck, while oral administration is via a feeding needle. In both cases, a volume of 0.2ml was used per mouse. Compounds were administered 30 minutes, 4 hours and 24 hours after challenge. Control compounds of known efficacy were included in each trial administered by the same route. Animals were observed daily and the number of survivors per group was recorded. Pasteurella multocida model monitoring lasted 96 hours (four days) after challenge.

PD₅₀Is the calculated dose of test compound to protect 50% of mice in a group from death due to bacterial infection that would be fatal in the absence of drug treatment.

The crystalline forms of the invention (hereinafter "active compound") may be administered by the oral, parenteral, topical or rectal route to treat or prevent bacterial or protozoal infections. In general, the most desirable dosage range for administration of the active compound is from about 0.2mg per kg body weight per day (mg/kg/day) to about 200 mg/kg/day in single or multiple administrations (i.e., 1 to 4 times per day), although variations will necessarily occur depending on the species, body weight and condition of the subject and the particular route of administration chosen. However, a dosage level in the range of about 2 mg/kg/day to about 50 mg/kg/day is most preferably employed. Variations may nevertheless exist depending on the species of mammal, fish or bird being treated and its individual response to the drug treatment, as well as the type of pharmaceutical formulation selected and the time period and interval at which such administration is carried out. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful side effects, provided that such larger doses are first divided into several small doses for administration throughout the day.

The active compounds may be administered by the routes previously described, either alone or in combination with a pharmaceutically acceptable carrier or diluent, and such administration may be carried out in single or multiple doses. More specifically, the active compounds can be administered in a wide variety of different dosage forms, that is, they can be combined with a variety of pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, cachets, oral powders, aqueous slurries, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media, and various non-toxic organic solvents, and the like. Furthermore, oral pharmaceutical compositions may be suitably sweetened and/or flavored. Generally, the concentration level of the active compound in such dosage forms ranges from about 1.0% to about 70% by weight.

For oral administration, tablets may be employed which contain various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine, and various disintegrants such as starch (preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, together with granulation binders such as polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricants such as magnesium stearate, sodium lauryl sulfate, and talc are often very useful for tableting purposes. Solid compositions of a similar type may also be employed as fillers in gelatin capsules; preferred materials in this regard also include lactose or milk sugar and high molecular weight polyethylene glycols. When aqueous slurries and/or elixirs are desired for oral administration, the active ingredient may be combined with various sweetening or flavoring agents, coloring matter or dyes, and emulsifying and/or suspending agents, if desired, together with diluents such as water, ethanol, propylene glycol, glycerin and various combinations thereof.

For parenteral administration, solutions of the active compounds in sesame or peanut oil or aqueous propylene glycol may be employed. The aqueous solution should be suitably buffered (preferably at a pH greater than 8) if necessary, first to render the liquid diluent isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oil solution is suitable for intra-articular, intramuscular and subcutaneous injection purposes. Preparation of all these solutions under sterile conditions is readily accomplished using standard pharmaceutical techniques well known to those skilled in the art.

In addition, it is also possible to administer the active compounds topically, which can be done with the aid of creams, jellies, gels, pastes, ointments and the like, in accordance with standard pharmaceutical practice.

For administration to animals other than humans, such as cattle or livestock, the active compound may be administered in animal feed or orally as a veterinary drench composition.

The active compounds can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine or phosphatidylcholines.

Claims (15)

1. A crystalline form of azithromycin selected from the group consisting of form D, form E, substantially pure form F, substantially pure form G, form H, form J, form M substantially free of azithromycin dihydrate, form N, form O, form P, form Q and form R.

2. A crystalline form of azithromycin according to claim 1 wherein said form is form D, further characterised by¹³The C solid state NMR spectrum had chemical shift peaks of about 178.1ppm, 103.9ppm, 95.1ppm, 84.2ppm, 10.6ppm, 9.0ppm, and 8.6 ppm.

3. A crystalline form of azithromycin according to claim 1 wherein said form is form E.

4. A crystalline form of azithromycin according to claim 1 wherein said form is substantially pure form F further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.5ppm, 178.6ppm, 58.0ppm, 10.1ppm, 9.8ppm, 9.3ppm, 7.9ppm, and 6.6 ppm.

5. A crystalline form of azithromycin according to claim 4 wherein said azithromycin comprises 90% or more by weight of form F azithromycin.

6. The crystalline form according to claim 1, wherein said crystalline form is substantially pure form G, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.5ppm, 10.4ppm, 9.9ppm, 9.3ppm, 7.6ppm, and 6.5 ppm.

7. A crystalline form of azithromycin according to claim 6 wherein said azithromycin comprises 90% or more by weight of form G azithromycin.

8. The crystalline form according to claim 1, wherein said crystalline form is form H, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.5ppm, 178.7ppm, 9.9ppm, 9.1ppm, 7.9ppm, and 7.0 ppm.

9. The crystalline form according to claim 1, wherein said crystalline form is form J, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.6ppm, 178.4ppm, 25.2ppm, 11.5ppm, 10.0ppm, 9.3ppm, 8.1ppm, and 6.8 ppm.

10. The crystalline form according to claim 1, wherein said crystalline form is substantially free of aForm M in the presence of spectinomycin dihydrate, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.6ppm, 41.9ppm, 26.0ppm, 16.3ppm, 10.3ppm, 9.6ppm, 9.3ppm, 7.7ppm, and 7.1 ppm.

11. The crystalline form according to claim 1, wherein said crystalline form is form N, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 179.6ppm, 178.7ppm, 105.6ppm, 58.1ppm, 26.0ppm, 9.9ppm, 9.4ppm, 7.9ppm, and 6.6 ppm.

12. The crystalline form according to claim 1, wherein the crystalline form is form O.

13. The crystalline form according to claim 1, wherein the crystalline form is form P.

14. The crystalline form according to claim 1, wherein the crystalline form is form Q.

15. The crystalline form according to claim 1, wherein said crystalline form is form R, further characterized by¹³The C solid state NMR spectrum had chemical shift peaks of about 177.9ppm, 103.6ppm, 95.3ppm, 10.3ppm, 9.6ppm, 8.9ppm, and 8.6 ppm.