ME02261B - Process for preparing atazanavir bisulfate and novel forms - Google Patents

Description

PROCEDURE FOR THE PREPARATION OF ATAZANAVIR BISULFATE AND NEW FORMS

 

Description

 

INVITATION TO OTHER APPLICATIONS

 

[0001] The presented application has the priority of US provisional application no. 60/568,043, which was filed on May 4, 2004, and 60/607,533, which was filed on September 7, 2004.

 

OBLAST PRONALASKA

 

[0002] The present invention relates to a process for the preparation of the HIV protease inhibitor atazanavir bisulfate and its new forms.

 

OSNOVA PRONALASKA

 

[0003] USA Patent no. 5,849,911 to Fässler et al. describes a series of azapeptide HIV protease inhibitors (which include atazanavir) having the structure

 

where

 

R1 is lower alkoxycarbonyl,

R2 is secondary or tertiary lower alkyl or lower alkylthio-lower alkyl,

R3 is phenyl which is unsubstituted or substituted with one or more lower alkoxy radicals, or C4-C8 cycloalkyl,

R4 is phenyl or cyclohexyl each substituted at position 4 by an unsaturated heterocyclyl which is attached through a ring carbon atom, has from 5 to 8 ring atoms, contains from 1 to 4 hetero atoms selected from nitrogen, oxygen, sulfur, sulfinyl (-SO -) and sulfonyl (-SO2-) and is unsubstituted or substituted with lower alkyl or with phenyl-lower alkyl,

R5, independently of R2, has one of the meanings given for R2, i

R 6 , independently of R 1 , is lower alkoxycarbonyl, or a salt thereof, with the proviso that at least one salt-forming group is present and includes various pharmaceutically acceptable acid addition salts.

[0004] Several procedures are provided for the preparation of azapeptides including the preparation of compounds where R1 and R6, and R2 and R5 are in each case two identical radicals, wherein the diamino compound of the structure

 

(a)

 

is condensed with the acid structure

(b)

 

or with a reactive acid derivative thereof, wherein R1' and R2' are as defined for R1 and R6, and for R2 and R5, respectively.

 

[0005] In the formation of atazanavir using the aforementioned procedure, the diamino compound (a) will have the structure

 

was prepared by coupling epoxy

 

with hirazinocarbamate

 

in the presence of isopropyl alcohol to form the protected diamine

 

which is treated with hydrochloric acid in the presence of a solvent such as tetrahydrofuran to form the diamine (a)

 

[0006] The diamine was isolated and used in the next coupling step where it reacted with acid (b)

 

or its reactive ester using a coupling agent such as O-(1,2-dihydro-2-oxo-1-pyridyl)-N,N,N1,N1-tetramethyluronium-tetrafluoro-borate (TPTU).

[0007] The diamine free base was found to be unstable and therefore undesirable for use in the preparation of atazanavir free base.

[0008] USA Patent no. 6,087,383 to Singh et al. describes the bisulfate salt of the azapeptide HIV protease inhibitor known as atazanavir having the structure

 

(also labeled as atazanavir bisulfate or atazanavir sulfate).

[0009] Example 3 of Singh et al. describes the preparation of atazanavir bisulfate in type-II crystals which are hydrated hygroscopic and crystalline forms, and type-I crystals which appear to be anhydrous/desolvated crystalline forms.

 

BRIEF DESCRIPTION OF THE INVENTION

 

[0010] In accordance with the present invention, new forms of atazanavir bisulfate are provided which include form C material and form E3. Form C material is preferred.

[0011] In addition, in accordance with the present invention, there is provided a process for the preparation of atazanavir bisulfate in the form of crystals of Form A (Pharmaceutical substance) (which are designated as crystals of type I in Example 3 of US Patent No. 6,087,383 to Singh et al) . Form A crystals prepared by the process of the invention have the desired substantially consistent particle size distribution and substantially consistent mean particle size, and are used in the conversion to form C material, a partially crystalline material, which is formulated with various excipients to prepare a drug product.

[0012] The process according to the invention for the preparation of crystals of form A of atazanavir bisulfate salt uses a modified cubic crystallization technique where sulfuric acid is added at an increasing rate according to the cubic unit (as described hereinbelow), and comprises the steps of reacting a solution of atazanavir free base in an organic solvent that is acetone or a mixture of acetone and N-methyl pyrrolidone with the first portion of concentrated sulfuric acid in an amount to react with less than about 15%, preferably less than about 12%, by weight of atazanavir free base, adding atazanavir bisulfate form A crystals into the reaction mixture, and as atazanavir bisulfate form crystals, adding additional concentrated sulfuric acid in multiple stages at increasing rates according to the cubic equation to achieve form A crystals.

[0013] Additionally, in accordance with the present invention, a process is provided for the preparation of a form of atazanavir derived from and comprising atazanavir bisulfate, and designated as Form C material. Form C may be produced by suspending crystals of Form A in water and drying . Alternatively, the Form C material can be formed by subjecting the Form A crystal to a high relative humidity of greater than about 95% RH (water vapor) for at least 24 hours. Form C material can also be formed by wet granulating atazanavir bisulfate or a combination of atazanavir bisulfate and excipients and drying the wet granulation.

[0014] In a preferred embodiment, crystals of Form A are mixed with formulation excipients such as one or more bulking agents, for example lactose, one or more disintegrants, such as crospovidone, and wet granulated to directly form material of form C mixed with excipients.

[0015] Further in accordance with the present invention, a new form of atazanavir bisulfate is provided, namely, form E3 which is a highly crystalline form of the triethanolate solvate of atazanavir bisulfate.

[0016] Form E3 was prepared by preparing a thick suspension of atazanavir free base in ethanol, treating the thick suspension with concentrated sulfuric acid, heating and seeding the resulting solution with ethanol-moistened E3 crystals, treating the mixture with heptane (or another solvent such as toluene or hexane) , filtering and drying.

[0017] Further in accordance with the presented invention, a process for the preparation of crystals of form A of atazanavir bisulfate is provided, which includes the steps of preparing the triamine salt of the structure

 

(preferably HCl (3 mol) salt) and without isolating the triamine salt, the reaction of the triamine salt with the active ester, preferably with the structure

 

in the presence of a base and an organic solvent to form atazanavir free base which, without isolation, was converted to atazanavir bisulfate via a modified cubic crystallization technique as described herein.

[0018] Additionally, a composition of atazanavir bisulfate comprising atazanavir bisulfate as Form A crystals or Form C material, and a pharmaceutically acceptable carrier therefor, is described. A pharmaceutically acceptable carrier may include fillers, binders, disintegrants, lubricants, and other common excipients.

[0019] Different forms of atazanavir bisulfate according to the invention can be characterized using different techniques, which are well known to those skilled in the art. Shapes can be characterized and distinguished using single crystal X-ray diffraction, which is based on unit cell measurements of a single crystal shape at a fixed analytical temperature. A detailed description of unit cells is given in Stout & Jensen, X-Ray Structure Determination: A Practical Guide, Macmillan Co., New York (1968), Chapter 3, which is incorporated herein by reference. Alternatively, the unique spatial arrangement of atoms within the crystal lattice can be characterized by recorded fractional atomic coordinates. The next means of characterizing the crystal structure is by X-ray powder diffraction analysis in which the experimental or recorded diffraction profile is compared to a simulated profile representing the pure powder material, both performed at the same analytical temperature, and the measurements for the subject shape are characterized as a series of 2θ values.

[0020] Other means of shape characterization can be used, such as solid state nuclear magnetic resonance (SSNMR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). These parameters can also be used in combination to characterize the shape of the subject.

[0021] Form A crystals can be characterized by unit cell parameters that are substantially the same as the following:

 

Cell dimensions:

[0022]

 

a =9.86(5) Å

b= 29.245(6) Å

c = 8.327(2) Å

α = 93.56(2)°

β = 114.77(3)°

γ = 80.49(3)°

 

Space group 1

Molecules/asymmetric unit 2

where the crystalline form is at about +22°C.

[0023] Form A can be characterized by fractional atomic coordinates substantially as listed in Table 3 and crystal structure substantially as shown in Figure 2 .

[0024] Form A can be characterized by simulated and recorded X-ray powder diffraction patterns substantially as shown in Figure 1 .

[0025] Form A can be characterized by a differential scanning calorimetry (DSC) thermogram having an endotherm with a peak onset at about 165.6°C significantly as shown in Figure 3.

[0026] Form A can be characterized by a thermal gravimetric analysis (TGA) curve having negligible weight loss up to about 100°C to 150°C significantly as shown in Figure 4 .

[0027] Form A can be characterized by solid state NMR (SSNMR) chemical shifts significantly as shown in Table 4 and by spectra significantly as shown in Figure 5.

[0028] Form A can be characterized by fractional atomic coordinates substantially as listed in Table 5.

[0029] Form A salt can be characterized by moisture-sorption isotherms with about 0.1% weight gain in the range of 25 to 75% RH at 25°C.

[0030] In one aspect of the present invention, pattern C can be characterized by a recorded X-ray powder diffraction pattern substantially as shown in Figure 6 .

[0031] In a different aspect of the present invention, pattern C can be characterized by a differential scanning calorimetry thermogram substantially as shown in Figure 7 having an endotherm typically in the range of about 76.7 to about 96.6°C and from about 156.8 to about 165.9°C. .

[0032] In a different aspect of the present invention, Form C can be characterized by a thermal gravimetric analysis curve having a weight loss of about 2.4% at about 125°C and a weight loss of about 4.4% up to about 190°C significantly as shown in FIG. Pictures 8.

[0033] In accordance with the present invention, form E3 can be characterized by crystallographic data as shown in Table 5, substantially equal to the following:

 

a = 10.749 Å

b = 13.450(4) Å

c = 9.250(2) Å

α = 98.33(2)°

β = 95.92(3)°

γ = 102.82(3)°

 

Spatial group P1

Molecules/asymmetric unit 1

when the crystalline form is at about -23°C.

[0034] In a different aspect of the present invention, the E3 form can be characterized using fractional atomic coordinates substantially as listed in Table 6.

[0035] In a different aspect of the present invention, form E3 can be characterized by simulated and recorded X-ray powder diffraction patterns substantially as shown in Figure 9 .

[0036] In a different aspect of the present invention, form E3 can be characterized by a differential scanning calorimetry thermogram having an endotherm typically within the range of about 89.4 to about 96.6°C substantially as shown in Figure 11.

[0037] In a different aspect of the present invention, form E3 can be characterized by a thermal gravimetric analysis curve having a weight loss of about 14.7% at about 150°C significantly as shown in Table 8.

[0038] In a different aspect of the invention, form E3 can be characterized using a crystal structure as shown in Figure 10.

 

BRIEF DESCRIPTION OF PICTURES

[0039]

Figure 1 shows the calculated (simulated) (22°C) and recorded (experimental at room temperature) X-ray powder diffraction patterns (CuKα λ = 1.5418 A) of form A;

Figure 2 shows the crystal structure of Form A;

Figure 3 shows a differential scanning calorimetry (DSC) thermogram of form A;

Figure 4 shows the thermal gravimetric analysis (TGA) curve of form A;

Figure 5 shows C-13 solid state NMR of Form A;

Figure 6 shows the recorded (experimental at room temperature) X-ray powder diffraction pattern (CuKα λ = 1.5418 Å) of pattern C;

Figure 7 shows a differential scanning calorimetry thermogram of pattern C;

Figure 8 shows the thermal gravimetric analysis curve of Form C;

Figure 9 shows the calculated (simulated) (22°C) and recorded (experimental at room temperature) X-ray powder diffraction patterns (CuKα λ = 1.5418 Å) of form E3;

Figure 10 shows the crystal structure of form E3; and

Figure 11 shows the differential scanning calorimetry (DSC) thermogram of form E3, and the thermal gravimetric analysis curve of form E3.

 

 

 

DETAILED DESCRIPTION OF THE INVENTION

 

[0040] The present invention provides, at least in part, forms of atazanavir bisulfate, namely form E3 and form C, as new materials, particularly in a pharmaceutically acceptable form. The term "pharmaceutically acceptable", as used herein, means those compounds, materials, compositions, and/or dosage forms which, within the scope of sound medical judgment, are suitable for contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problematic complications commensurate with a reasonable benefit/risk ratio. In certain preferred embodiments, the crystalline forms of the free base I and its salts are in substantially pure form. The term "substantially pure", as used herein, means a compound having a purity greater than about 90% including, for example, about 91%, about 92%, about 93%, about 94%, about 95%, about 96% , about 97%, about 98%, about 99%, and about 100%.

[0041] As used herein, "polymorph" refers to crystalline forms having the same chemical composition, but different spatial arrangements of the molecules, atoms and/or ions that form the crystal.

[0042] As used herein "solvate" means a crystalline form of molecules, atoms and/or ions that further contains molecules of one or more solvents incorporated into the crystalline structure. The solvent molecules in the solvate can be present in a regular arrangement and/or a disordered arrangement. A solvate can contain either a stoichiometric or a non-stoichiometric amount of solvent molecules. For example, a solvate with a non-stoichiometric amount of solvent molecules may result from partial loss of solvent from the solvate.

[0043] Samples of crystalline forms may be provided with substantially pure phase homogeneity, indicating the presence of a dominant amount of one crystalline form and optionally minor amounts of one or more other crystalline forms. The presence of more than one crystalline form in a sample can be determined using techniques such as powder X-ray diffraction (PXRD) or solid state nuclear magnetic resonance spectroscopy (SSNMR). For example, the presence of additional peaks in the comparison of the experimentally measured PXRD pattern with the simulated PXRD pattern may indicate more than one crystalline form in the sample. Simulated PXRD can be calculated from single crystal X-ray data. See Smith, D.K., "A FORTRAN Program for Calculating X-Ray Powder Diffraction Patterns," Lawrence Radiation Laboratory, Livermore, California, UCRL-7196 (April 1963). Preferably, the crystalline form has substantially pure phase homogeneity as indicated by less than 10%, preferably less than 5%, and more preferably less than 2% of the total peak area in the experimentally measured PXRD pattern arising from additional peaks absent from of the simulated PXRD pattern. Most preferred is a crystalline form having substantially pure phase homogeneity with less than 1% of the total peak area in the experimentally measured PXRD pattern arising from additional peaks absent from the simulated PXRD pattern.

[0044] Procedures for the preparation of crystalline forms are known in the art. Crystalline forms can be prepared by various methods, including, for example, crystallization or recrystallization from a suitable solvent, sublimation, melt growth, solid state transformation from a second phase, crystallization from a supercritical fluid, and jet spraying. Techniques for crystallization or recrystallization of crystalline forms from a solvent mixture include, for example, evaporating the solvent, lowering the temperature of the solvent mixture, seeding crystals of a supersaturated solvent mixture of molecules and/or salts, freeze-drying the solvent mixture, and adding an anti-solvent ("anti-solvent ") into the solvent mixture.

[0045] Drug crystals, including polymorphs, procedures for the preparation and characterization of drug crystals are discussed in Solid-State Chemistry of Drugs, S.R. Bym, R.R. Pfeiffer, and J.G. Stowell, 2nd Edition, SSCI, West Lafayette, Indiana (1999).

[0046] For crystallization techniques that use a solvent, the choice of one or more solvents typically depends on one or more factors, such as the solubility of the compound, the crystallization technique, and the vapor pressure of the solvent. Combinations of solvents may be used, for example, the compound may be solubilized in a first solvent to obtain a solution, followed by the addition of an anti-solvent to reduce the solubility of the compound in the solution and to ensure crystal formation. An anti-solvent is a solvent in which the compound has low solubility. Suitable solvents for crystal preparation include polar and non-polar solvents.

[0047] In one process for the preparation of crystals, atazanavir bisulfate is suspended and/or mixed in a suitable solvent to obtain a thick suspension, which can be heated to stimulate dissolution. The term "thick suspension", as used herein, means a saturated solution of atazanavir bisulfate or a salt thereof, which may also contain an additional amount of atazanavir bisulfate or a salt thereof to obtain a heterogeneous mixture of atazanavir bisulfate or a salt thereof and a solvent at a given temperature. Suitable solvents in this sense include, for example, polar aprotic solvents and polar protic solvents, and mixtures of two or more thereof as mentioned herein.

[0048] Seeding crystal seeds can be added to any crystallization mixture to stimulate crystallization. As will be apparent to one skilled in the art, seeding is used as a means of controlling the growth of a particular crystal form or as a means of controlling the particle size distribution of a crystalline product. Therefore, the calculation of the amount of seeds required for seeding depends on the size of seeds available and the desired average particle size of the product as described, for example, in "Programmed cooling of batch crystallizers," J.W. Mullin and J. Nyvlt, Chemical Engineering Science (1971) 26:369-377. In general, smaller seed sizes are required to effectively control crystal growth in a batch. Smaller-sized seeds can be generated by sieving, grinding or micronizing larger crystals or using solution micro-crystallization. It is necessary to take care that the grinding or micronization of the crystal does not result in any change in crystallinity from the desired crystal form (ie change to amorphous or to another polymorph).

[0049] The cooled mixture can be filtered under vacuum, and the isolated solids can be washed with a suitable solvent, such as a cold recrystallization solvent, and dried under a nitrogen purge to obtain the desired crystalline form. The isolated solids can be analyzed using a suitable spectroscopic or analytical technique, such as SSNMR, DSC, PXRD, or the like, to ensure the formation of the desired crystalline form of the product. The resulting crystalline form is typically produced in an amount greater than about 70% by weight of the isolated yield, but preferably greater than 90% by weight based on the weight of atazanavir bisulfate originally used in the crystallization process. The product can be simultaneously ground or passed through a sieve to remove lumps from the product, if necessary.

[0050] The crystalline forms can be prepared directly from the reaction medium of the final step of the procedure for the preparation of atazanavir bisulfate. This can be achieved, for example, by using in the final step of the process a solvent or solvent mixture from which atazanavir bisulfate can be crystallized. Alternatively, crystalline forms can be obtained by distillation or solvent addition techniques. Suitable solvents for this purpose include any of the solvents described herein, including protic polar solvents such as alcohols, and aprotic polar solvents such as ketones.

[0051] As a general guide, the reaction mixture can be filtered to remove any unwanted impurities, inorganic salts and the like, followed by washing with the reaction or crystallization solvent. The resulting solution may be concentrated to remove excess solvent or gaseous constituents. If distillation is used, the final amount of distillate collected may vary, depending on process factors including, for example, vessel size, stirring capability, and the like. As a general guide, the reaction solution can be distilled to about {fraction (1/10)} of the original volume before solvent exchange is performed. The reaction can be sampled and tested to determine the extent of the reaction and severity. % of product in accordance with standard procedure techniques. If desired, additional reaction solvent can be added or removed to optimize the reaction concentration. Preferably, the final concentration is adjusted to about 50 wt. % at which point a thick suspension typically results.

[0052] It may be desirable to add the solvents directly to the reaction vessel without distilling the reaction mixture. Preferred solvents for this purpose are those that can eventually participate in the crystal lattice as discussed above in relation to solvent change. Although the final concentration may vary depending on the desired purity, isolation, and the like, the final concentration of free base I in solution is preferably about 4% to about 7%. The reaction mixture can be stirred after the addition of the solvent and simultaneously heated. By way of illustration, the reaction mixture may be stirred for about 1 hour while heating to about 70°C. The reaction is preferably hot filtered and washed with either reaction solvent, additional solvent, or a combination thereof. Crystal seeds can be added to any crystallization solution to initiate crystallization.

[0053] The various forms described herein can be distinguished from each other through the use of various analytical techniques known to those skilled in the art. Such techniques include, but are not limited to, solid state nuclear magnetic resonance spectroscopy (SSNMR), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and/or thermogravimetric analysis (TGA).

[0054] It will be clear to one skilled in the art that an X-ray diffraction pattern can be obtained with a measurement error that is dependent on the measurement conditions used. In particular, it is generally known that the intensities in the X-ray diffraction pattern can fluctuate depending on the measurement conditions used and the shape or morphology of the crystal. It should be further understood that the relative intensities may also vary depending on the experimental conditions and, therefore, the exact order of the intensities should not be taken into account. In addition, the measurement error of the diffraction angle for a conventional X-ray diffraction pattern is typically about 0.2% or less, preferably about 0.1% (as discussed hereinbelow), and such a degree of measurement error should be considered as referring to previously mentioned diffraction angles. Consequently, it is to be understood that the crystalline forms of the present invention are not limited to those crystal forms which give X-ray diffraction patterns identical to the X-ray diffraction patterns shown in the accompanying figures herein. All crystalline forms which give X-ray diffraction patterns substantially identical to those shown in the accompanying Figures are within the scope of the present invention. The ability to determine the significant identities of X-ray diffraction patterns is within the scope of one of ordinary skill in the art.

[0055] The term "form" as used herein in connection with form A and form E3 means a homogeneous crystalline structure.

[0056] The term "pattern" as used herein in connection with pattern C material means a characteristic X-ray diffraction pattern.

[0057] The term "atazanavir bisulfate" as used herein refers to atazanavir bisulfate as well as atazanavir sulfate.

[0058] In carrying out the procedure according to the invention for the preparation of crystals of form A of atazanavir bisulfate salt, a technique of modified cubic crystallization was used where atazanavir free base is dissolved in an organic solvent in which atazanavir bisulfate salt is significantly insoluble and which is acetone, or a mixture of acetone and N -methyl pyrrolidone, to obtain a solution having a concentration of atazanavir free base within the range of about 6.5 to about 9.7% by weight, preferably from about 6.9 to about 8.1% by weight of atazanavir free base.

[0059] A solution of atazanavir free base is heated to a temperature within the range of 35 to 55°C, preferably 40 to 50°C, and reacted with an amount of concentrated sulfuric acid (containing about 95 to about 100% H 2 SO 4 ) to react with less than 15%, preferably from 5 to less than 12%, more preferably from 8 to 10% by weight of total atazanavir free base. Thus, the starting solution of atazanavir free base will initially react with less than 15%, preferably 5 to 12%, by weight of the total amount of sulfuric acid to be used. During the reaction, the reaction mixture was maintained at a temperature within the range of 35 to 55°C, preferably 40 to 50°C.

[0060] The reaction is allowed to proceed for a period of from about 12 to about 60 minutes, preferably from about 15 to about 30 minutes.

[0061] The reaction mixture was seeded with atazanavir bisulfate Form A crystals using a seed amount within the range of 0.1 to 80% by weight, preferably 3 to 8% by weight, based on the weight of atazanavir free base remaining in the reaction mixture while maintaining the reaction mixture at temperature within the range of 35 to 55°C, preferably from 40 to 50°C.

[0062] The reaction was allowed to proceed until crystallization began. Next, sulfuric acid is added in multiple stages at an increasing rate according to the cubic equation as described below to form atazanavir bisulfate which on drying produces crystals of form A.

[0063] The size of the crystal particles and the morphology of the formed atazanavir bisulfate salt depend on the rate of addition of sulfuric acid, which determines the rate of crystallization. A modified "cubic" crystallization technique (acid added at an increasing rate according to the cubic equation) was found to yield relatively larger, more defined crystals of atazanavir bisulfate, along with a narrower particle size range and smaller particle size, than constant addition rate crystallization. A slow initial acid flow rate has been shown to favor crystal growth over secondary nucleation. Thus, as surface area increases with particle size, the germ layer is able to accommodate increasing acid flow rates without inducing secondary nucleation. The slow initial addition rate allows time for the crystals to grow, increasing the mean size. Cubic crystallization produces a less compressible filter cake, which aids in efficient cake liquid removal and washing, as well as giving a more easily dried product with fewer hard lumps than the constant feed rate crystallization product.

[0064] The cubic crystallization procedure used is temperature-controlled crystallization derived from Mullin, "Crystallization, 3rd Ed.", 1993, Butterworth-Heineman, Pubs. and is defined by the following simplified equation:

 

where

 

Tmax = initial temperature for crystallization

Tmin = final temperature for crystallization

time = time spent in crystallization

time total = total crystallization time.

 

[0065] Considering that the crystallization of atazanavir bisulfate is controlled by the rate of addition of sulfuric acid, the temperature variable is replaced by the volume of acid in equation (1). In this equation, the variable representing the minimum volume has been removed.

 

where

 

Vtime = Volume of sulfuric acid added during the elapsed time period

Vtotal = Total volume of acid representing 90% filling

time = Time elapsed in crystallization

time total = Total crystallization time.

 

Equation (2) is labeled the "cubic equation."

[0066] By controlling the crystallization rate using this expression, nucleation is controlled within acceptable limits as the system maintains a constant low level of super-saturation.

[0067] Form A crystals were identified by X-ray powder diffraction pattern and crystal structure as shown in Figures 1 and 2, respectively.

[0068] Form A crystals of atazanavir bisulfate or form C material as well as form E3 prepared as described above are final atazanavir bisulfate and can be used as drug products for administration to patients.

[0069] According to the process according to the invention, the material of form C can be prepared by exposing crystals of form A to water after drying.

[0070] In a further process in accordance with the present invention, the form C material can be formed by exposing the form A crystal to a high relative humidity of more than about 95% RH, preferably from about 95 to about 100% RH (water vapor), for at least 24 hours. , preferably from about 24 to about 48 hours.

[0071] In the following embodiment of the invention, the Form C material is prepared by wet granulating atazanavir bisulfate form A to produce atazanavir bisulfate granules and then drying the granules.

[0072] In performing the wet granulation process, atazanavir bisulfate will be granulated in water and dried at a temperature within the range of about 40 to about 80°C, preferably within the range of about 50 to about 60°C. The drying step will preferably be carried out for at least about 2 hours, up to about 20 hours, preferably from about 8 to about 10 hours.

[0073] Form C material may also be formed by wet granulation of atazanavir bisulfate form A in the presence of conventional pharmaceutical excipients, for example, one or more bulking agents, preferably lactose, one or more disintegrants, preferably crospovidone, and drying as is described above to form the material of form C in the mixture with excipients.

[0074] It is a form C, form A or form E3 material, preferably a form C material, which is formulated for use in the treatment of viral diseases as described hereinbelow.

[0075] Form C material was characterized by its X-ray powder diffraction pattern as shown in Figure 3.

[0076] Form E3 was prepared by suspending atazanavir free base in ethanol, treating the thick suspension with concentrated sulfuric acid using an acid:free base molar ratio ranging from about 1:1 to about 1.1:1, heating the resulting solution to from about 30 to about 40°C, seeding the solution with ethanol-moistened atazanavir sulfate E3 crystals, treating the mixture with heptane (or other solvent such as hexane or toluene), filtering, and drying to produce atazanavir bisulfate form E3 (triethanol solvate).

[0077] The seeding step will use an amount of seed to achieve E3 crystal formation, for example a molar ratio of atazanavir bisulfate E-3:free base seed within the range of about 0.02:1 to about 0.04:1.

[0078] Form E3 was identified by the X-ray powder diffraction pattern as shown in Figure 7 and the crystal structure as shown in Figure 6.

[0079] In accordance with the presented invention, atazanavir in the form of its free base was prepared by solution treatment of the protected triamine salt structure

 

(where PG represents a protecting group such as t-butyloxycarbonyl (Boc) or trifluoroacetyl, preferably Boc, with an acid, preferably hydrochloric acid (where Boc was used), or a base (where trifluoroacetyl was used) in the presence of an organic solvent such as methylene chloride, tetrahydrofuran or methanol, wherein the solvent is preferably methylene chloride, at a temperature within the range of about 25 to about 50°C, preferably from about 30 to about 40°C, to form the triamine acid salt, preferably the hydrochloride salt of the structure

 

and without isolating the triamine acid salt, by reacting the triamine acid salt with the active acid ester of the structure

 

preferably with an active ester structure

 

in the presence of a base such as K2HPO4, diisopropylethylamine, N-methylmorpholine, sodium carbonate, or potassium carbonate, preferably K2HPO4, in the presence of an organic solvent such as methylene chloride, a mixture of ethyl acetate and butyl acetate, acetonitrile or ethyl acetate, preferably methylene chloride, at a temperature within the range of 25 to 50°C, preferably 30 to 40°C to form the atazanavir free base.

[0080] The protected triamine starting material was prepared by an epoxide reaction

 

where PG is preferably Boc such as N-(tert-butyloxycarbonyl)-2(S)-amino-1-phenyl-3(R)-3,4-epoxy-butane, with hydrazine carbamate

 

where PG is preferably Boc in the presence of isopropyl alcohol or another alcohol such as ethanol or butanol.

[0081] Atazanavir bisulfate is useful for administration to warm-blooded animals, particularly humans, for the treatment or prevention of disease responsive to inhibition of a retroviral protease, particularly a retroviral aspartate protease, such as HIV-1 or HIV-II gag protease, for example retroviral diseases, such as AIDS or its preliminary stages.

[0082] Atazanavir bisulfate, especially material of form C, form A or form E3, preferably material of form C or form A, can be used for the treatment of diseases caused by viruses, especially retroviruses, especially AIDS or its preliminary stages, where it is therapeutically effective. an amount of atazanavir bisulfate form C, form A or form E3 material applied in a dose effective in the treatment of the said disease especially to a warm-blooded animal, for example a human being, which on account of one of the said diseases, especially AIDS or its preliminary stages, requires such treatment. A preferred dose to be administered to warm-blooded animals, for example human beings of approximately 70 kg body weight, is from about 3 mg to about 1.5 g, preferably from about 10 mg to about 1.25 g, for example from about 50 mg to about 600 mg per person per day, divided preferably into 1 to 4 individual doses which may, for example, be of the same size. Usually, children receive half the adult dose. It is preferably administered orally.

[0083] The atazanavir bisulfate form C, form A or form E3 material is used for the pharmaceutical uses described above. Suitable compositions containing Form C material or Form A or Form E3 for oral administration include tablets, powders, capsules and elixirs. About 10 to 600 mg of the active ingredient is admixed with a physiologically acceptable carrier, carrier, excipient, binder, preservative, stabilizer, flavor enhancer, etc., in a unit dosage form as indicated by accepted pharmaceutical practice.

[0084] Pharmaceutical compositions for oral administration can be obtained by combining the active ingredient with solid carriers, if desired by granulating the resulting mixture, and processing the mixture, if desired or if necessary, after adding appropriate excipients, into tablets, dragee cores, capsules or powders for oral use. It is also possible for the active ingredients to be incorporated into plastic carriers that allow the active ingredients to diffuse or be released in metered amounts.

[0085] Bulking agents or fillers will be present in the pharmaceutical compositions of the invention in an amount within the range of about 0 to about 95% by weight and preferably from about 10 to about 85% by weight of the composition. Examples of bulking agents or fillers suitable for use herein include, but are not limited to, cellulose derivatives such as microcrystalline cellulose or wood cellulose, lactose, sucrose, starch, pregelatinized starch, dextrose, mannitol, fructose, xylitol, sorbitol, corn starch , modified corn starch, inorganic salts such as calcium carbonate, calcium phosphate, dicalcium phosphate, calcium sulfate, dextrin/dextrates, maltodextrin, compressible sugars, and other known bulking agents or fillers, and/or mixtures of two or more of the foregoing mentioned, preferably lactose.

[0086] The binding agent will optionally be present in the pharmaceutical compositions of the invention in an amount within the range of about 0 to about 20% by weight, preferably from about 1 to about 10% by weight of the composition. Examples of binders suitable for use herein include, but are not limited to, hydroxypropyl cellulose, corn starch, pregelatinized starch, modified corn starch, polyvinyl pyrrolidone (PVP) (molecular weight in the range of about 5,000 to about 80,000, preferably about 40,000), hydroxypropylmethyl cellulose (HPMC), lactose, gum acacia, ethyl cellulose, cellulose acetate, as well as a waxy binding agent such as carnauba wax, paraffin, spermaceti, polyethylene or microcrystalline wax, as well as other conventional binding agent and/or mixtures of two or more of them, preferably hydroxypropyl cellulose.

[0087] The disintegrant will optionally be present in the pharmaceutical composition of the invention in an amount within the range of about 0 to about 20% by weight, preferably from about 0.25 to about 15% by weight of the composition. Examples of disintegrants suitable for use herein include, but are not limited to, croscarmellose sodium, crospovidone, potato starch, pregelatinized starch, corn starch, sodium starch glycolate, microcrystalline cellulose, or other known disintegrant, preferably croscarmellose sodium.

[0088] The lubricant will optionally be present in the pharmaceutical composition of the invention in an amount within the range of about 0.1 to about 4% by weight, preferably from about 0.2 to about 2% by weight of the composition. Examples of tabletable lubricants suitable for use herein include, but are not limited to, magnesium stearate, zinc stearate, calcium stearate, talc, carnauba wax, stearic acid, palmitic acid, sodium stearyl fumarate or hydrogenated vegetable oils and fats, or other known tabletable lubricants, and/or mixtures of two or more of the above, preferably magnesium stearate.

[0089] Capsules are hard gelatin capsules and also soft, sealed capsules made from gelatin and a plasticizer, such as glycerol or sorbitol. Hard gelatin capsules may comprise the active ingredient in granule form, for example with fillers such as lactose, binding agents such as starches, crospovidone and/or glidants such as talc or magnesium stearate, and if desired with stabilizers. In soft gelatin capsules, the active ingredient is preferably dissolved or suspended in suitable oily excipients, such as fatty oils, paraffin oil or liquid polyethylene glycols, where it is similarly possible to add stabilizers and/or antibacterial agents.

[0090] The following examples represent examples of implementation according to the invention.

 

FIRST 1

 

1-[4-(Pyridin-2-yl)phenyl]-5(S)-2,5-bis{[N-(methoxycarbonyl)-L-tert-leucinel]amino}-4-(S)-hydroxy- 6-phenyl-2-azahexane, Bisulfate so (oblique A) (Atazanavir bisulfate – oblique A)

A.

[0091]

 

(1-[4-(Pyridin-2-yl)phenyl]-5(S)-2,5-bis[tert-butyloxycarbonyl)amino]-4(S)-hydroxy-6-phenyl-2-azahexane.3HCl (Triamine.3HCl))

 

[0092] The protected triamine 1-[4-(pyridin-2-yl)phenyl]-5(S) was added to a 1000 mL three-necked, round-bottomed vessel equipped with a mechanical stirrer, nitrogen inlet, and temperature probe. -2,5-bis[tert-butyloxycarbonyl)amino]-4(S)-hydroxy-6-phenyl-2-azahexane

 

(100 g, 0.178 mol), and CH2Cl2 (500 mL; 5 mL/g protected starting triamine) (prepared as described in Z. Xu et al., Process Research and Development for an Efficient Synthesis of the HIV Protease Inhibitor BMS -232,632, Organic Process Research and Development, 6, 323-328 (2002)) and the resulting thick suspension was stirred while maintaining the temperature at from about 5 to about 22°C.

[0093] Concentrated hydrochloric acid (68 mL, 0.82 mol, 4.6 eq.) was added to the reaction mixture at a rate such that the temperature of the reaction mixture was maintained between 5 and 30°C. The reaction mixture was heated to 30 to 40°C and stirred until the reaction was judged to be complete by HPLC assay.

[0094] Water was added (70-210 mL, 0.7-2.1 mL/g protected input triamine) to the reaction mixture, the reaction mixture was stirred for 15 minutes and the phases were allowed to separate. The upper phase, product-rich aqueous oil (triamine.3HCl salt) was transferred to the addition funnel.

 

B.

[0095]

 

(Active ester of N-methoxycarbonyl-L-tert-leucine

 

 

[0096] Into a 3000 mL three-necked, round-bottomed vessel equipped with a mechanical stirrer, addition funnel, nitrogen inlet, and temperature probe was added N-methoxycarbonyl-L-tert-leucine (77.2 g, 0.408 mol, 2.30 eq.), 1-hydroxybenzotriazole (HOBT) (60.8 g, 0.450 mol, 2.53 eq.), and N-ethyl N'-dimethylaminopropyl carbodiimide (EDAC) (82.0 g, 0.430 mol, 2.42 eq.), followed by CH2Cl2 ( 880 mL; 8.8 mL/g protected input triamine) and the mixture was stirred at ambient temperature (18-25°C) until formation of the active ester was complete, as judged by HPLC.

 

C. 1-[4-(Pyridin-2-yl)phenyl]-5(S)-2,5-bis{[N-(methoxycarbonyl)-L-tert-leucinyl]amino}-4(S)-hydroxy -6-phenyl-2-azahexane (atazanavir free base)

 

[0097] Anhydrous dibasic potassium phosphate (K2HPO4; 226 g, 1.30 mol, 7.30 equiv protected triamine wrt) was dissolved in 1130 mL water (11.3 mL/g protected amine; 5 mL/g K2HPO4).

[0098] The K2HPO4 solution was added to the active ester solution prepared in part B. To the mixed active ester/aqueous K2HPO4 solution, an aqueous solution of form A of the hydrochloride salt was slowly added over a period of 1.5 to 2.0 h while maintaining stirring and the vessel temperature between 5 and 20°C.

[0099] After the addition of part A solution of the hydrochloride salt was completed, the reaction mixture (coupling reaction) was heated to 30-40°C and stirred until the coupling reaction was judged complete by HPLC assay.

[0100] The coupling mixture is cooled to 15 to 20°C and the lower, product-rich organic phase is separated from the upper, spent aqueous phase.

[0101] The product-rich organic phase was washed with 1M NaH2PO4 (880 mL; pH=1.5; 8.8 mL/g protected triamine input; 5 mol eq. protected triamine wrt), allowed to separate, and the spent aqueous phase was removed.

[0102] The washed product-rich organic phase was mixed with 0.5 N NaOH (800 mL; 8 mL/g protected feedstock) until HPLC assay of the rich organic phase indicated that each of the active esters was below 0.3 I.I. The phases were allowed to separate and the spent aqueous phase was removed.

[0103] The rich organic phase was washed with 5% NaH 2 PO 4 (450 mL, 4.5 mL/g protected input triamine; pH=4.3), the phases were allowed to separate and the spent aqueous phase was removed.

[0104] The rich organic phase was washed with 10 w/v% NaCl (475 mL, 4.75 mL/g protected input triamine) and the spent aqueous phase was removed.

[0105] The concentration of the title free base in solution was 120 to 150 mg/mL with a yield calculated in the process of 95-100 mol%.

 

D. Solvent change from CH2Cl2 to acetone/N-methylpyrrolidone

 

[0106] To a rich solution of part C free base in a 3000 mL three-necked round-bottom vessel equipped with a mechanical stirrer, temperature probe, and distillation condenser, was added N-methylpyrrolidone (148 mL; 1.25 mL/g part C free bases based on in-process quantification test). The solution is concentrated to about 360 mL (2.5-3.5 mL/g of part C free base) using a wraparound heater temperature of 70°C or less; 500 mL of acetone (4-5 mL/g of part C free base) was added to the concentrated solution and the mixture was distilled to a volume of about 400 mL or less.

[0107] Addition of acetone and distillation were repeated until the in-process test showed that the CH2Cl2 level had reached the target end point. At the crystallization volume, the content of CH2Cl2 in the rich organic solution was 0.77 vol./vol. %. Acetone was added to the concentrated free base solution to reach a total solution of 16 mL/g free base. The temperature of the bath was maintained at 40-50°C to prevent crystallization of the free base. The solution was filtered with a polished filter, through a 10-micron or finer filter while maintaining the temperature at 40 to 50°C. The polished filter was washed with acetone (125 mL, 1.0 mL/g free base) and the wash residue was added to the free base-rich acetone/N-methylpyrrolidone solution used in the next step.

 

E. 1-[4-(Pyridin-2-yl)phenyl]-5(S)-2,5-bis{[N-(methoxycarbonyl)-L-tert-leucinel]amino}-4(S)-hydroxy by -6-phenyl-2-azahexane bisulfation

 

[0108] About 10% (2 g) of the total charge of concentrated sulfuric acid (19 g, 1.10 eq.) was added to the free base and acetone/N-methylpyrrolidone solution of Part D, maintaining the temperature at 40-50°C, via -surface addition.

[0109] The reaction mixture was seeded with 5.0 wt. % (calculated free base wrt in solution) of the bisulfate salt. The seeded mixture was stirred at 40-50°C for at least 30 minutes during which time the bisulfate salt began to crystallize as confirmed by the increase in transparency of the mixture over time.

[0110] The remaining sulfuric acid (17.8 g) was added over about 5 h in five stages according to the following protocol, defined by the cubic equation, while maintaining the temperature at 40-50°C.

[0111] The rate of each additional stage is determined according to the cubic equation described hereinabove and is tabulated below.

 

TABLE 1

Stadium

mL/kg/h

mL(H2SO4)/h

g(H2SO4)/h

Duration (min)

1

4.62

0.579

1.065

60

2

6.93

0.868

1.597

60

3

16.55

2.073

3.814

60

4

30.26

3.790

6.974

60

5

48.47

6.071

11.171

23

 

[0112] After the addition of H2SO4 was complete, the thick suspension was cooled to 20-25°C for at least 1 h with stirring. The thick suspension was stirred at 20-25°C for at least 1 h. The bisulfate salt was filtered and the mother liquor was recycled as necessary to achieve complete transfer. The filter cake was washed with acetone (5-10 mL/g free base; 1200 mL acetone). The bisulfate salt was dried at NMT 55°C under vacuum to LOD <1% to produce crystalline material.

[0113] The crystalline product was analyzed by PXRD, DSC and TGA patterns and SSNMR spectra and found to be (non-solvated) crystals of the title bisulfate form A (see Figures 1 to 5).

TABLE 2

Table of crystallographic data

Form A

T°C

a(A)

b(A)

c(A)

a°

b°

c°

V(Å3)

WITH'

sg

dcalc

R

+22

9.861(5)

29.245(6)

8.327(2)

93.56(2)

114.77(3)

80.49(3)

2150(2)

2

P1

1.240

0.06

T= temp(°C) for crystallographic data.

Z' = number of drug molecules per asymmetric unit

 

 

TABLE 3

Table of fractional parameters and their estimated standard deviations for form A

Atom

x

and

With

B(A2)

S1

0.3230(4)

0.5467(1)

0.5608(5)

8.0(1)

O100

0.431(1)

0.5060(3)

0.649(1)

11.1(3)

O102

0.335(1)

0.5498(4)

0.383(1)

12.0(4)

O103

0.360(1)

0.5877(4)

0.655(2)

12.0(4)

O104

0.176(1)

0.5384(4)

0.528(1)

11.8(4)

S51

0.6177(4)

0.4505(1)

0.4003(5)

7.2(1)

O150

0.596(1)

0.4430(4)

0.564(1)

12.5(4)

O152

0.518(1)

0.4921(4)

0.317(1)

13.8(4)

O153

0.588(1)

0.4121(3)

0.289(2)

12.2(4)

O154

0.768(1)

0.4587(4)

0.454(1)

12.1(4)

O4

0.6985(7)

0.1753(3)

0.6456(9)

5.7(2)

O7

0.1687(8)

0.1941(3)

0.3411(9)

6.5(2)

O11

-0.0352(7)

0.2482(3)

0.0308(8)

5.7(2)

O14

0.2280(7)

0.1769(3)

-0.233(1)

6.1(2)

O15

0.0399(8)

0.1335(3)

-0.330(1)

6.4(2)

O17

0.6169(7)

0.2821(3)

0.963(1)

7.1(2)

O18

0.3750(7)

0.2905(3)

0.9136(9)

6.2(2)

N2

0.5015(9)

0.2182(3)

0.902(1)

4.5(2)

N5

0.4642(8)

0.1647(3)

0.6001(9)

4.2(2)

N9

0.2317(9)

0.2788(3)

0.256(1)

5.1(2)

N10

0.1820(9)

0.2760(3)

0.069(1)

4.6(2)

N13

-0.0148(8)

0.2083(3)

-0.280(1)

4.6(2)

N39

-0.087(1)

0.5265(3)

0.272(1)

6.1(3)

C1

0.491(1)

0.2627(4)

0.924(1)

5.5(3)

C3

0.6381(9)

0.1908(3)

0.892(1)

4.0(2)

C4

0.600(1)

0.1764(4)

0.702(1)

4.6(3)

C6

0.420(1)

0.1551(4)

0.403(1)

5.1(3)

C7

0.295(1)

0.1936(4)

0.297(1)

5.1(3)

C8

0.357(1)

0.2400(4)

0.346(2)

5.4(3)

C11

0.051(1)

0.2592(4)

-0.028(1)

4.9(3)

C12

0.024(1)

0.2531(4)

-0.223(1)

4.5(3)

C14

0.094(1)

0.1732(4)

-0.280(1)

4.7(3)

C16

0.146(2)

0.0943(5)

-0.342(2)

10.9(5)

C19

0.616(1)

0.3313(4)

0.996(2)

8.1(4)

C20

0.701(1)

0.1485(4)

1.025(1)

5.8(3)

C21

0.842(1)

0.1219(5)

1.007(2)

7.9(4)

C22

0.583(2)

0.1160(5)

0.997(2)

8.0(4)

C23

0.748(2)

0.1713(5)

1.215(1)

8.2(4)

C24

0.365(1)

0.1079(4)

0.356(2)

6.6(4)

C25

0.484(1)

0.0691(4)

0.470(1)

6.5(3)

C26

0.643(2)

0.0684(5)

0.520(2)

8.4(5)

C27

0.753(2)

0.0293(6)

0.622(2)

11.4(6)

C28

0.709(3)

-0.0044(7)

0.691(3)

15.0(9)

C29

0.553(2)

-0.0032(5)

0.644(2)

14.2(7)

C30

0.441(2)

0.0343(5)

0.534(2)

10.8(4)

C31

0.291(1)

0.3229(4)

0.311(2)

5.7(3)

C32

0.177(1)

0.3650(4)

0.259(1)

5.4(3)

C33

0.224(1)

0.4064(4)

0.262(2)

6.3(3)

C34

0.122(1)

0.4487(5)

0.233(2)

6.9(4)

C35

-0.031(1)

0.4469(4)

0.189(1)

4.8(3)

C36

-0.081(1)

0.4043(4)

0.180(1)

5.6(3)

C37

0.019(1)

0.3629(4)

0.218(1)

5.4(3)

C38

-0.136(1)

0.4918(4)

0.170(1)

5.3(3)

C40

-0.170(1)

0.5683(4)

0.279(2)

7.8(4)

C41

-0.318(2)

0.5736(5)

0.158(2)

9.1(5)

C42

-0.376(2)

0.5403(5)

0.035(2)

9.0(5)

C43

-0.283(1)

0.4964(5)

0.039(2)

8.1(4)

C44

-0.096(1)

0.2937(4)

-0.345(1)

6.2(3)

C45

-0.258(1)

0.2901(5)

-0.366(2)

8.5(4)

C46

-0.085(2)

0.2890(6)

-0.530(2)

10.8(5)

C47

-0.057(2)

0.3393(5)

-0.265(2)

8.9(5)

O54

0.2347(7)

0.8167(3)

0.8392(8)

5.3(2)

O57

0.7713(8)

0.7950(3)

1.0561(9)

5.9(2)

O61

0.9725(7)

0.7436(3)

0.9141(8)

5.3(2)

O64

0.7062(7)

0.8164(3)

0.427(1)

5.9(2)

O65

0.8911(8)

0.8598(2)

0.535(1)

6.1(2)

O67

0.3150(8)

0.7090(3)

1.184(1)

6.4(2)

O68

0.5587(9)

0.6986(3)

1.377(l)

6.6(2)

N52

0.4313(9)

0.7713(3)

1.271(1)

4.9(2)

N55

0.4709(8)

0.8265(3)

1.0332(9)

4.2(2)

N60

0.7555(8)

0.7179(3)

0.728(1)

4.6(2)

N63

0.9491(8)

0.7852(3)

0.601(1)

4.4(2)

N89

1.026(1)

0.4719(3)

0.711(1)

6.0(3)

C51

0.442(1)

0.7247(4)

1.282(1)

5.4(3)

C53

0.296(1)

0.7996(4)

1.141(1)

5.1(3)

C54

0.3347(9)

0.8159(3)

0.989(1)

4.1(3)

C56

0.519(1)

0.8353(4)

0.887(1)

4.7(3)

C57

0.644(1)

0.7959(4)

0.886(1)

4.5(3)

C58

0.587(1)

0.7494(4)

0.854(1)

5.2(3)

C61

0.884(1)

0.7334(4)

0.766(1)

4.2(3)

C62

0.914(1)

0.7392(4)

0.603(1)

4.4(3)

C64

0.839(1)

0.8196(4)

0.513(1)

4.6(3)

C66

0.785(2)

0.8996(5)

0.433(3)

12.1(7)

C69

0.323(1)

0.6588(4)

1.202(2)

8.8(5)

C70

0.237(1)

0.8409(4)

1.232(1)

5.6(3)

C71

0.092(1)

0.8701(5)

1.080(2)

7.6(4)

C72

0.352(1)

0.8744(4)

1.328(2)

7.1(4)

C73

0.187(1)

0.8195(6)

1.362(1)

8.9(4)

C74

0.570(1)

0.8825(4)

0.907(2)

6.4(3)

C75

0.450(1)

0.9206(4)

0.919(1)

6.3(3)

C76

0.296(2)

0.9236(5)

0.813(2)

8.1(4)

C77

0.188(2)

0.9614(6)

0.826(2)

11.2(5)

C78

0.244(2)

0.9942(6)

0.960(2)

15.2(7)

C79

0.405(3)

0.9935(6)

1.062(2)

13.9(7)

C80

0.504(2)

0.9552(4)

1.043(2)

9.3(5)

C81

0.644(1)

0.6672(4)

0.832(2)

6.2(3)

C82

0.762(1)

0.6266(3)

0.839(1)

4.7(3)

C83

0.723(1)

0.5934(4)

0.696(2)

6.1(3)

C84

0.822(1)

0.5547(4)

0.695(2)

5.9(3)

Q85

0.967(1)

0.5478(4)

0.828(1)

5.0(3)

C86

1.009(1)

0.5783(4)

0.971(2)

6.6(4)

C87

0.908(1)

0.6184(4)

0.971(2)

6.4(4)

C88

1.076(1)

0.5070(4)

0.827(1)

5.5(3)

C90

1.111(1)

0.4326(4)

0.690(2)

7.4(4)

Q91

1.258(2)

0.4262(5)

0.792(2)

17.8(4)

Q92

1.324(2)

0.4578(5)

0.918(2)

8.7(5)

C93

1.230(1)

0.4994(5)

0.936(2)

6.9(4)

C94

1.038(1)

0.7005(4)

0.584(1)

4.8(3)

C95

1.196(1)

0.7055(4)

0.717(2)

6.7(4)

C96

1.021(2)

0.7049(5)

0.392(2)

8.9(4)

C97

0.998(1)

0.6536(4)

0.614(2)

7.6(4)

N59

0.7084(8)

0.7114(3)

0.866(1)

5.1(2)

H391

0.047

0.523

0.383

6.0*

H891

0.931

0.477

0.646

5.8*

H15’

0.491

0.471

0.600

3.8*

H15"

0.440

0.512

0.322

4.6*

 

[0114] Most hydrogens are omitted; only the hydrogens at N9 and the acid are included.

[0115] Anisotropically processed atoms are given in the form of an isotropically equivalent substitution parameter defined as: (4/3) * [a2*B(1,1) + b2*B(2,2) + c2*B(3,3) + ab(cos gamma)*B(1,2)x+ ac(cos beta)*B(1,3) + bc(cos alpha)*B(2,3)].

[0116] Form A was characterized by a differential scanning calorimetry thermogram having an endotherm typically in the range of about 165.6°C to about 200.9°C as shown in Figure 3 .

[0117] Form A was also characterized by a thermal gravimetric analysis curve to have negligible weight loss up to about 100 to 150°C.

[0118] Crystals produced using cubic crystallization where H 2 SO 4 is added at an increasing rate according to the cubic equation described above were relatively larger and more defined, and had a narrower particle size range and smaller particles, than crystals obtained using constant addition rate crystallization. .

[0119] The resulting filter cake using the cubic crystallization technique was less compressible than that obtained using constant addition rate crystallization, which helped in efficient cake liquid removal and washing and produced a homogeneous product.

 

TABLE 4

Carbon-13 SSNMR chemical shifts for form A, measured relative to TMS (tetramethyl silane)

d/ppm

26.9

27.5

33.9

37.7

49.2

53.5

62.7

63.3

66.0

69.2

69.5

122.6

123.7

125.3

126.1

127.6

128.5

129.4

131.1

134.4

138.8

139.7

140.6

143.2

143.9

149.9

150.3

153.9

159.3

172.0

 

FIRST 2

 

Atazanavir Bisulfate - Form C material

 

Procedure A:

 

[0120] Form A crystals of atazanavir bisulfate (prepared as described in Example 1) (25.33 g) were suspended in 200 mL of water and the mixture was stirred mechanically to produce a thick gel which was dried.

[0121] The dried mixture was milled with a spatula to produce material form C. The X-ray powder diffraction pattern of material form C is shown in Figure 6 .

 

Procedure B:

 

[0122] Form A crystals of atazanavir bisulfate were wet granulated using a sufficient amount of water (about 40% w/w) in a suitable mixer-granulator. The wet mass was dried in the oven. The product is sorted by size using a convenient sieve. The X-ray diffraction pattern of the obtained product is consistent with the sample C material as shown in Figure 6.

[0123] Form C is characterized by the differential scanning calorimetry thermogram shown in Figure 7 having an endotherm typically in the range of about 76.7 to about 96.6°C and from about 156.8 to about 165.9°C.

[0124] Form C was also characterized by a thermal gravimetric analysis curve having a weight loss of about 2.4% at about 125°C and about 4.4% at about 190°C as shown in Figure 8 .

 

FIRST 3

 

Atazanavir Bisulfat – oblique E3 (triethanol solvate)

 

[0125] Atazanavir free base (prepared as described in Example 1, part C) (3.0 g, 4.26 mmol) was suspended in dry, 200 strength ethanol (20.25 mL, 6.75 mL/g free base) in a 100 mL beaker. with three necks and a round bottom that is equipped with a mechanical stirrer, a temperature probe and a funnel for adding liquid that equalizes the pressure.

[0126] Concentrated H 2 SO 4 (0.25 mL, 0.46 g, 4.69 mmol, 1.1 eq.) was added to a thick suspension of atazanavir free base that was maintained at 20-25°C. The resulting solution (KF from 0.2 to 1.0% water) was filtered through a smooth filter (Whatman #1 paper), the filter was washed with 2.25 mL of absolute ethanol, and the liquid residue from the wash was added to the filtered solution. The solution was heated to 37°C and seeded with 10 mg of amorphous atazanavir bisulfate derived from form E3 crystals (by exposing form E3 crystals to ambient temperature), and the mixture was stirred for 15 min. Heptane (380 mL, 8.25 mL/g free base) was added over 1 hour. The resulting crystallization mixture was stirred for 8 hours at 15-25°C. Crystallized atazanavir bisulfate was filtered on a Büchner funnel. The product cake was washed with 184 mL (4 mL/g free base) of 1:1 ethanol:heptane. The product cake was washed with 46 mL (1 mL/g free base) of heptane. The obtained product was dried under vacuum at 40-50°C until it had LOD = 0.97%. The product yield was 47.7 g (0.0594 mol, 74.3 mol %) of atazanavir bisulfate form E3 (triethanol solvate) with HPLC HI=100.0 (see Figures 9 and 10).

 

TABLE 5

Table of crystallographic data

Form E3

T°C

a(Å)

b(A)

c(A)

a°

b°

c°

V(Å3)

WITH'

sg

dcalc

R

-23

10.749(5)

13.450(4)

9.250(2)

98.33(2)

95.92(3)

102.82(3)

1277(2)

1

P1

1.223

0.06

T= temp(°C) for crystallographic data.

Z' = number of drug molecules per asymmetric unit

 

TABLE 6

Table of fractional parameters and their estimated standard deviations for form E3

Atom

x

and

With

B(A2)

Busy if not equal to 1

S99

0.5568(1)

0.0760(1)

0.5936(1)

3.45(2)

 

O1

0.4200(5)

0.5541(4)

0.8496(5)

6.9(1)

 

O2

0.2889(5)

0.6016(4)

1.0066(6)

8.1(1)

 

O4

0.7004(4)

0.4509(3)

1.0233(4)

4.23(8)

 

O8

0.2913(4)

0.2932(3)

1.1074(4)

4.23(8)

 

O12

0.1057(4)

0.1088(3)

0.9299(4)

4.16(8)

 

O15'

0.329(1)

-0.0602(9)

1.064(1)

4.8(3)*

.3

O15"

0.324(2)

-0.156(1)

1.003(2)

3.2(3)*

.17

O15

0.3312(7)

-0.1150(6)

1.0380(8)

4.9(1)*

.53

Q16

0.1810(5)

-0.1433(3)

1.1819(4)

5.7(1)

 

O86

0.391(1)

0.6646(7)

0.6196(9)

11.5(4)

 

O89

0.3714(7)

0.5646(5)

0.3408(6)

6.5(2)

 

O90

0.7502(4)

0.2721(3)

0.8957(5)

4.99(9)

 

O95

0.4984(4)

0.0446(3)

0.7188(4)

4.50(8)

 

O96

0.6644(4)

0.0315(3)

0.5660(4)

4.83(8)

 

O97

0.4651(4)

0.0667(3)

0.4636(4)

5.08(9)

 

O98

0.6112(5)

0.1957(3)

0.6332(5)

5.9(1)

 

N2

0.4938(5)

0.6229(3)

1.0921(5)

4.8(1)

 

N5

0.5365(4)

0.4385(3)

1.1609(4)

3.16(8)

 

N10

0.2952(4)

0.2239(3)

0.8056(4)

3.17(8)

 

N11

0.2716(4)

0.1163(3)

0.7961(4)

3.08(8)

 

N14

0.1336(5)

-0.0874(4)

0.9743(5)

4.9(1)

 

N38

-0.2764(4)

0.0574(3)

0.2878(4)

3.24(8)

 

C1

0.4011(6)

0.5893(4)

0.9712(7)

5.3(1)

 

C3

0.6225(5)

0.6026(4)

1.0813(5)

3.9(1)

 

C4

0.6231(5)

0.4896(3)

1.0873(5)

3.19(9)

 

C6

0.5220(5)

0.3284(3)

1.1691(5)

3.14(9)

 

C8

0.4026(5)

0.2632(3)

1.0653(5)

3.21(9)

 

C9

0.4165(5)

0.2747(4)

0.9050(5)

3.6(1)

 

C12

0.1740(5)

0.0661(4)

0.8596(5)

3.4(1)

 

C13

0.1592(5)

-0.0523(4)

0.8367(5)

3.8(1)

 

Q15

0.2248(6)

-0.1124(5)

1.0627(6)

4.6(1)

 

C17

0.2720(9)

-0.1732(6)

1.2842(7)

7.3(2)

 

C18

0.1818(9)

0.5715(9)

0.894(1)

11.2(3)

 

C19

0.7292(7)

0.6818(4)

1.1928(7)

5.8(2)

 

C20

0.725(1)

0.7914(6)

1.169(1)

10.7(3)

 

C21

0.8613(9)

0.6645(8)

1.165(1)

10.5(3)

 

C22

0.710(1)

0.6694(7)

1.3507(8)

10.2(3)

 

C23

0.5158(5)

0.3135(4)

1.3298(5)

3.8(1)

 

C24

0.6305(6)

0.3765(4)

1.4359(5)

4.0(1)

 

C25

0.7519(7)

0.3708(6)

1.4192(7)

6.1(2)

 

C26

0.8581(7)

0.4279(9)

1.5213(9)

7.9(2)

 

C27

0.8398(8)

0.4935(6)

1.6375(8)

8.6(2)

 

C28

0.715(1)

0.5002(6)

1.6576(7)

8.0(2)

 

C29

0.6112(8)

0.4430(5)

1.5589(6)

6.0(2)

 

C30

0.3043(5)

0.2519(4)

0.6582(5)

3.6(1)

 

C31

0.1813(5)

0.2051(4)

0.5532(5)

3.4(1)

 

C32

0.0645(5)

0.2123(4)

0.5934(5)

3.9(1)

 

C33

-0.0489(5)

0.1725(4)

0.4957(5)

3.8(1)

 

C34

-0.0441(5)

0.1243(4)

0.3503(5)

3.16(9)

 

C35

0.0756(5)

0.1176(4)

0.3097(5)

3.9(1)

 

C36

0.1867(5)

0.1568(4)

0.4095(5)

3.9(1)

 

C37

-0.1615(5)

0.0853(4)

0.2417(4)

3.11(9)

 

C39

-0.3885(5)

0.0247(4)

0.1969(5)

3.9(1)

 

C40

-0.3891(5)

0.0200(4)

0.0470(5)

4.2(1)

 

C41

-0.2737(6)

0.0469(4)

-0.0057(5)

4.1(1)

 

C42

-0.1596(5)

0.0781(4)

0.0890(5)

3.7(1)

 

C43

0.0488(6)

-0.1114(4)

0.7094(6)

4.6(1)

 

C44

-0.0819(7)

-0.0958(6)

0.7378(9)

6.8(2)

 

C45

0.0496(9)

-0.2266(5)

0.6929(9)

7.8(2)

 

C46

0.0797(8)

-0.0738(5)

0.5667(7)

6.2(2)

 

C84

0.569(1)

0.7880(9)

0.725(1)

6.3(3)

 

Q85

0.448(1)

0.7726(9)

0.673(2)

8.4(4)

 

C87

0.204(1)

0.449(1)

0.405(2)

10.6(4)

 

C88

0.240(1)

0.517(1)

0.316(1)

8.6(3)

 

Q91

0.8826(7)

0.2919(5)

0.8896(8)

5.8(2)

 

Q92

0.9613(7)

0.3439(6)

1.035(1)

7.8(2)

 

H381

-0.275

0.053

0.403

3.2

 

H891

0.397

0.602

0.446

6.6

 

H981

0.658

0.219

0.717

6.6

 

 

[0127] Most of the hydrogens are omitted; only the hydrogens at N9 and the acid are included.

[0128] The anisotropically processed atoms are given in the form are given in the form of the isotropically equivalent substitution parameter defined as: (4/3) * [a2*B(1,1) + b2*B(2,2) + c2*B( 3,3) + ab(cos gamma)*B(1,2)x+ ac(cos beta)*B(1,3) + bc(cos alpha)*B(2,3)].

[0129] Form E3 was characterized by a differential scanning calorimetry thermogram having an endotherm typically within the range of about 89.4 to about 96.6 as shown in Figure 11 .

[0130] Form E3 was also characterized by a thermal gravimetric analysis curve having a weight loss of about 14.7% at about 150°C as shown in Figure 11 .

 

FIRST 4

 

[0131] Form C atazanavir bisulfate capsule formulations having the following composition were prepared as described below.

 

Ingredient

Granulation flow (% wt./wt.)

50-mg capsule (mg/capsule)

100-mg capsule (mg/capsule)

200-mg capsule (mg/capsule)

Atazanavir bisulfate

63.2

56.84b

113.67b

227.34b

Lactose, Monohydrate, NF

30.4

27.33c

54.69c

109.35c

krospovidon, NF

6.0

5.39

10.79

21.58

Magnesium stearate, NF

0.4

0.36d

0.72d

1.44d

Purified Water, USP or Water for Injection, USP

Sufficient quantity

Sufficient quantity

Sufficient quantity

Sufficient quantity

Capsule size #4

-

After 1

-

-

Capsule size #2

-

-

After 1

-

Capsule size #0

-

-

-

After 1

Total weight of filling

100.0

89.9

179.9

359.7

and Atazanavir bisulfate stock granulation for capsules (55.5% w/w as free base) was used to produce 50 mg, 100 mg, and 200 mg capsules.

b This amount is expressed according to atazanavir bisulfate at 100% potency, and is equal to 55.5% w/w. as a free base.

c The amount of lactose, hydrated will vary depending on the purity of atazanavir bisulfate and the amount of magnesium stearate used.

d The amount of magnesium stearate used can vary from 0.4% w/w. up to 0.8% w/w

e This was used for processing only and was removed by drying.

 

[0132] A granulation stock of atazanavir bisulfate was prepared as follows, in which the material of form C was formed.

[0133] Atazanavir bisulfate form A, hydrated lactose and a portion of crospovidone (3% by weight of the total crospovidone present) were mixed in a planetary mixer. The resulting mixture was wet granulated with purified water to convert Form A to Form C material. The wet granulation was dried in a rack dryer and sized using a hammer mill. The remaining crospovidone was added to the ground granulation and the mixture was blended in a PK V-blender. Magnesium stearate was added and the mixture was mixed until a substantially uniform stock granulation was formed.

[0134] Appropriate weights of stock granules were filled into capsules to produce 50 mg, 100 mg and 200 mg capsules containing atazanavir bisulfate.

 

FIRST 5

 

[0135] Atazanavir bisulfate Form A powder material for oral formulation having the following composition was prepared as described below.

 

Ingredients

Quantity (% w/w)

Atazanavir Bisulfate Oblik A

3.79

Aspartame, NF

10.00

Saharoza, N.F

81.21

Aroma of orange and vanilla

5.00

 

[0136] Atazanavir bisulfate form A is mixed with aspartame, orange-vanilla flavor and sucrose in a suitable mixer. The mixture was milled using a hammer mill, followed by a second mixing operation to obtain a uniform mixture. The product is filled in high-density polyethylene bottles.

 

Claims (27)

1. A process for the preparation of atazanavir bisulfate in the form of crystals of form A, comprising the reaction of a solution of atazanavir free base in an organic solvent, which is acetone or a mixture of acetone and N-methylpyrrolidone, with the first portion of concentrated sulfuric acid in an amount such that it reacts with less than about 15 % by weight of atazanavir free base, adding form A crystals of atazanavir bisulfate to the reaction mixture, as atazanavir bisulfate crystals form, adding additional concentrated sulfuric acid in multiple stages at an increasing rate according to the following equation where Vtime = volume of sulfuric acid added during the elapsed time time period Vtotal = total volume of acid representing 90% filling time = time elapsed in crystallization time total = total crystallization time or total time for acid loading to achieve atazanavir bisulfate crystal formation, and drying of atazanavir bisulfate to form A-form crystals. 2. The method according to claim 1 characterized in that the atazanavir free base solution initially reacts with from 5 to 15% by weight of the total amount of sulfuric acid used. 3. The method according to patent claim 1 characterized in that the atazanavir free base solution initially reacts with 8 to 12% by weight of the total amount of sulfuric acid used. 4. The method according to patent claim 1 characterized in that the atazanavir free base reacts with the first part of sulfuric acid at a temperature within the range of 35 to 55°C. 5. The method according to claim 1 characterized in that the atazanavir free base solution is heated to a temperature within the range of 35 to 55°C before reacting with sulfuric acid. 6. The method according to patent claim 1 characterized in that the reaction mixture of atazanavir free base and sulfuric acid is seeded with from 0.1 to 80% by weight of crystals of form A based on the weight of atazanavir free base. 7. The method according to patent claim 1 characterized in that the seeded reaction mixture is heated at a temperature within the range of 35 to 55°C. 8. The method according to patent claim 1 characterized in that the organic solvent for atazanavir free base is a mixture of acetone and N-methyl pyrrolidone. 9. A process for preparing atazanavir bisulfate form C material, comprising subjecting the atazanavir bisulfate form A crystals to a high relative humidity of at least about 95% RH for at least 24 hours and then drying. 10. A process for preparing atazanavir bisulfate Form C material, comprising (a) reacting a solution of atazanavir free base in an organic solvent, which is acetone or a mixture of acetone and N-methylpyrrolidone, with a first portion of concentrated sulfuric acid in an amount such that it reacts with less than about 15% by weight of atazanavir free base, addition of form A crystals of atazanavir bisulfate to the reaction mixture, as crystals of atazanavir bisulfate form, addition of concentrated sulfuric acid in multiple stages at an increasing rate according to the following equation where Vtime = volume of sulfuric acid added in during the elapsed time period Vtotal = total volume of acid representing 90% loading time = time elapsed in crystallization timetotal = total crystallization time or total time for acid loading to achieve atazanavir bisulfate crystal formation, and drying of atazanavir bisulfate to form crystals form A; (b) suspending the Form A atazanavir bisulfate crystals from step (a) in water and drying the suspension to form the Form C material; or (c) subjecting the Form A atazanavir bisulfate crystals of step (a) to a high relative humidity of greater than 95% RH for at least 24 hours to form the Form C material or (d) mixing the Form A crystals of step (a) with one or multiple formulation excipients and wet granulation of the mixture obtained directly from the Form C material in the mixture with the excipients. 11. The process according to patent claim 1 for the preparation of atazanavir bisulfate in the form of crystals of form A, which contains the preparation of the triamine salt of the structure and without isolation of the triamine salt, the reaction of the triamine salt with the active ester of the acid of the structure and a base in the presence of an organic solvent to form a solution of free atazanavir base structure and converting the free base into the corresponding bisulfate salt by treating a solution of the free base in methylene chloride with N-methyl pyrrolidone and acetone, heating the aforementioned mixture to remove the methylene chloride, and treating the aforementioned mixture with sulfuric acid to form the bisulfate salt of the free bases where sulfuric acid is added at an increasing rate according to the following equation where Vtime = volume of sulfuric acid added during the elapsed time period Vtotal = total volume of acid representing 90% filling time = elapsed time in crystallization time total = total crystallization time or total time to charge acid. 12. The method according to patent claim 11 characterized in that the triamine salt is a hydrochloride salt 13. The method according to claim 11, characterized in that the active acid ester has a structure 14. The method according to patent claim 11 characterized in that the base is alkali metal hydroxide, alkaline earth metal hydroxide, alkali metal carbonate, alkaline earth metal carbonate, alkali metal phosphate, alkaline earth metal phosphate or an organic base. 15. The method according to claim 14 characterized in that the base is NaOH, KOH, Mg(OH)2, K2HPO4, MgCO3, Na2CO3, K2CO3, triethylamine, diisopropylethylamine or N-methylmorpholine and the organic solvent is methylene chloride, ethyl acetate, dichloroethane, tetrahydrofuran, acetonitrile or N,N-dimethylformamide. 16. The method according to patent claim 11 characterized in that the triamine salt and the active ester reacted at a temperature within the range of 30 to 40°C. 17. The method according to patent claim 16 characterized in that the triamine salt and the active ester reacted in the presence of K2HPO4 as a base and methylene chloride as a solvent. 18. The process according to claim 11 including the step of seeding the mixture of free base, acetone and N-methylpyrrolidone with crystals of atazanavir bisulfate. 19. A process for the preparation of atazanavir bisulfate comprising the preparation of the triamine hydrochloride salt of the structure, the reaction of the triamine hydrochloride salt with the active ester of the structure and K2HPO4 in the presence of methylene chloride to form a solution of the free base of the structure in methylene chloride, and the conversion of the free base into the corresponding bisulfate salt via the technique cubic crystallization where sulfuric acid is added at an increasing rate according to the following equation where Vtime = volume of sulfuric acid added during the elapsed time period Vtotal = total volume of acid representing 90% filling time = elapsed time in crystallization time total = total crystallization time or total time for charging acid. 20. Form E3 atazanavir bisulfata. 21. The compound according to claim 20 prepared as a triethanolate solvate of atazanavir bisulfate. 22. The compound of claim 20 as indicated by an X-ray powder diffraction pattern substantially consistent with that shown in Figure 9. 23. The compound of claim 20 having the crystal structure substantially shown in Figure 10. 24. A compound according to claim 20 which is indicated by fractional atomic coordinates substantially as listed in Table 6. 25. The compound of claim 20 which is characterized by crystallographic data substantially equal to the following: cell dimensions: a = 10.749(5) Å b= 13.450(4) Å c = 9.250(2) Å α = 98.33(2)° β = 95.92 (3)° γ= 102.82(3)° space group P1 molecules/asymmetric unit 1 where the stated crystal form is at about -23°C. 26. The compound of claim 20 which is characterized by differential scanning calorimetry thermogram data substantially consistent with that shown in Figure 11. 27. A compound according to claim 20 which is indicated by a thermal gravimetric analysis curve substantially in accordance with that shown in Figure 11.