DESC:CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the earlier filing date of Indian Provisional Patent Application No. IN201841015814 filed on April 26, 2018; Indian Provisional Patent Application No. IN201841020810 filed on June 04, 2018; Indian Provisional Patent Application No. IN201841034008 filed on September 10, 2018.
FIELD OF THE INVENTION
The present disclosure encompasses crystalline forms of bictegravir, amorphous form of bictegravir sodium, amorphous solid dispersion of bictegravir sodium and processes for their production and pharmaceutical compositions thereof.
BACK GROUND OF THE INVENTION
Bictegravir (formerly known as GS-9883) also referred to as bictegravir free acid is a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor that was discovered by Gilead Sciences.

Bictegravir sodium is approved as part of a single tablet regimen in combination with tenofovir alafenamide (TAF) and emtricitabine (FTC) for the treatment of HIV-1 infection under the brand name of BIKTARVY®, marketed by Gilead Sciences. Bictegravir sodium is chemically known as (2R,5S,13aR)- 2,5-Methanopyrido[1’,2’:4,5]pyrazino[2,1-b][1,3]oxazepine-10-carboxamide, 2,3,4,5,7,9, 13,13a-octahydro-8-hydroxy-7,9-dioxo-N-[(2,4,6-trifluorophenyl)methyl]-, sodium salt (1:1), having the structure below:

Formula-I

Bictegravir is disclosed in U.S Patent No. 9,216,996 B2, which is hereby incorporated by reference.

The inventors of the present disclosure have developed novel crystalline forms of bictegravir, amorphous bictegravir sodium, amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers and a process for the preparation.

SUMMARY OF THE INVENTION
In one aspect, the present invention provides crystalline bictegravir Form M1, which may be characterized by a PXRD pattern having significant peaks at 2? angles of 5.23, 10.50, 15.79 and 17.84 ± 0.2°. Crystalline bictegravir Form M1 may also be characterized by a PXRD pattern as shown in Figure 1.
In another aspect, the present invention provides a process for the preparation of crystalline bictegravir Form M1. In one embodiment, crystalline bictegravir Form M1 may be prepared by a process comprising the steps of:
a) dissolving bictegravir sodium and fumaric acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M1.

In one aspect, the present invention provides crystalline bictegravir Form M2, which may be characterized by a PXRD pattern having significant peaks at 2? angles of 5.27, 10.54, 14.25, and 15.83 ± 0.2°. Crystalline bictegravir Form M2 may also be characterized by a PXRD pattern as shown in Figure 2.
In another aspect, the present invention provides a process for the preparation of crystalline bictegravir Form M2 comprising the steps of:
a) dissolving bictegravir sodium and succinic acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M2.

In another aspect, the present invention provides crystalline bictegravir Form M3, which may be characterized by a PXRD pattern having significant peaks at 2? angles of 5.25, 10.50, 14.22 and 16.47 ± 0.2°. Crystalline bictegravir Form M3 may also be characterized by a PXRD pattern as shown in Figure 3.
In another aspect, the present invention provides a process for the preparation of crystalline bictegravir Form M3 comprising the steps of:
a) dissolving bictegravir sodium and oxalic acid in a mixture of water and polar aprotic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M3.

In another aspect, the present invention provides crystalline bictegravir Form M4, which may be characterized by a PXRD pattern having significant peaks at 2? angles of 10.96, 16.98, 20.15, 22.16 and 26.01 ± 0.2°. Crystalline bictegravir Form M4 may also be characterized by a PXRD pattern as shown in Figure 4.

Other aspect of the present invention is to provide a process for the preparation of crystalline bictegravir Form M4 comprising the steps of:
a) dissolving bictegravir sodium and oxalic acid in a mixture of water and alcohol solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M4.

In another aspect, the present invention provides crystalline bictegravir Form M5, which may be characterized by a PXRD pattern having significant peaks at 2? angles of 5.12, 6.33, 10.35 and 17.59 ± 0.2°. Crystalline bictegravir Form M5 may also be characterized by a PXRD pattern as shown in Figure 5.

Another aspect of the present invention is to provide a process for the preparation of crystalline bictegravir Form M5, comprising drying the crystalline bictegravir Form M3 at 160-200 °C.

In another aspect, the present invention provides amorphous bictegravir sodium. Amorphous bictegravir sodium may also be characterized by a PXRD pattern as shown in Figure 6.

Another aspect of the present invention is to provide a process for the preparation of amorphous bictegravir sodium, which comprises:
a) dissolving bictegravir sodium in a solvent; and
b) removing the solvent and isolating the amorphous bictegravir sodium.

In another aspect, the present invention provides amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers.

Another aspect of the present invention is to provide a process for the preparation of amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers, which comprises:
a) dissolving bictegravir sodium in a solvent;
b) adding pharmaceutically acceptable carrier to the solution obtained in step (a);
c) removing the solvent and isolating the amorphous solid dispersion of bictegravir sodium.

Another aspect of the present invention is to provide a process for the preparation of amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers, which comprises:
a) dissolving bictegravir sodium and pharmaceutically acceptable carrier in a solvent; and
b) removing the solvent and isolating the amorphous solid dispersion of bictegravir sodium.

BRIEF DESCRIPTION OF THE FIGURES
Further aspects of the present disclosure together with additional features contributing thereto and advantages accruing there from will be apparent from the following description of embodiments of the disclosure which are shown in the accompanying drawing figures wherein:
Figure 1 is an X-ray powder diffractogram of crystalline bictegravir Form M1;
Figure 2 is an X-ray powder diffractogram of crystalline bictegravir Form M2;
Figure 3 is an X-ray powder diffractogram of crystalline bictegravir Form M3;
Figure 4 is an X-ray powder diffractogram of crystalline bictegravir Form M4;
Figure 5 is an X-ray powder diffractogram of crystalline bictegravir Form M5;
Figure 6 is an X-ray powder diffractogram of amorphous bictegravir sodium.
DETAILED DESCRIPTION OF THE DISCLOSURE
The present disclosure relates to crystalline forms of bictegravir, amorphous bictegravir sodium and amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers. The present disclosure also relates to process for the preparation of crystalline forms of bictegravir, amorphous bictegravir sodium and amorphous solid dispersion of bictegravir sodium.

Within the context of the present disclosure, the term “about” when modifying a temperature measurement is meant to mean the recited temperature plus or minus five degrees. Within the context of the present disclosure, the term “about” when modifying an absolute measurement, such as time, mass, or volume, means the recited value plus or minus 10% of the value.

Within the context of the present disclosure, the term “elevated temperature” means the temperature above 35°C and it is depending on the water/organic solvent ratio and the concentration of bictegravir sodium/organic acid.

The crystalline forms of bictegravir disclosed herein may be characterized by X-ray powder diffraction pattern (PXRD). Samples of each polymorph were analyzed on a BRUKER D-8 Discover powder diffractometer equipped with goniometer of ?/2? configuration and Lynx Eye detector. The Cu-anode X-ray tube was operated at 40kV and 30mA. The experiments were conducted over the 2? range of 2.0°-50.0°, 0.030° step size and 0.4 seconds step time.

In one aspect, the present invention provides crystalline bictegravir Form M1.

Within the context of the present invention, crystalline bictegravir Form M1 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.23, 10.50, 15.79 and 17.84 ± 0.2°. In another embodiment, crystalline bictegravir Form M1 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.23, 10.50, 12.38, 13.76, 14.21, 15.79 and 17.84 ± 0.2°. In yet another embodiments, crystalline bictegravir Form M1 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.23, 9.88, 10.50, 10.89, 12.38, 12.98, 13.76, 14.21, 15.79, 16.27, 17.24, 17.59, 17.84, 18.49, 18.80, 19.35, 20.07, 20.48, 20.82, 21.22, 21.59, 21.92, 23.32, 24.03, 24.47, 24.95, 25.23, 25.71, 26.16, 26.50, 27.31, 28.77, 29.44, 30.12, 30.37, 30.80, 31.93, 32.56, 33.34, 34.04, 35.06, 36.19, 37.45, 38.09, 38.89, 40.28, 43.04, 44.08, 44.96, 46.62, 47.34, 48.21, 48.75 and 49.36 ± 0.2°.

Another aspect of the present invention provides a process for the preparation of crystalline bictegravir Form M1 comprising the steps of:
a) dissolving bictegravir sodium and fumaric acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M1.

According to the present disclosure, bictegravir sodium and fumaric acid are dissolved in a mixture of water and organic solvent at elevated temperature. The reaction mass is cooled and stirred to produce a solid. The obtained solid may then filtered and dried to get crystalline bictegravir Form M1.

Within the context of the present disclosure, bictegravir sodium and fumaric acid are dissolved in a mixture of water and organic solvent at elevated temperature, preferably of about 80-90 °C.

Within the context of this embodiment of the present invention, the organic solvent employed may include, polar aprotic solvents such as dimethylformamide, dimethyl sulfoxide, dimethylacetamide or mixtures thereof. In particular useful embodiments of the present invention organic solvent is dimethyl sulfoxide.

Within the context of this embodiment of the present invention, isolation can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation. In particular useful embodiments of the present invention the solid is isolated by filtration followed by washing and drying.

In another aspect, the present invention provides crystalline bictegravir Form M2.

Within the context of the present invention, crystalline bictegravir Form M2 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.27, 10.54, 14.25 and 15.83 ± 0.2°. In another embodiments, crystalline bictegravir Form M2 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.27, 5.64, 9.92, 10.54, 10.93, 12.42, 12.94, 14.25, 15.83, 16.30, 17.28, 17.62, 17.87, 18.53, 18.84, 19.38, 20.10, 20.86, 21.20, 21.63, 21.96, 23.36, 24.07, 24.50, 25.27, 25.75, 26.20, 26.54, 27.33, 28.64, 29.48, 30.16, 30.43, 30.84, 31.98, 32.62, 33.40, 34.06, 35.10, 36.31, 37.49, 38.12, 38.93, 40.31, 43.08, 44.11, 44.97, 47.37, 48.80 and 49.37 ± 0.2°.

Another aspect of the present invention provides a process for the preparation of crystalline bictegravir Form M2 comprising the steps of:
a) dissolving bictegravir sodium and succinic acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M2.

According to the present disclosure, bictegravir sodium and succinic acid are dissolved in a mixture of water and organic solvent at elevated temperature. The reaction mass is cooled and stirred to produce a solid. The obtained solid may then filtered and dried to get crystalline bictegravir Form M2.

Within the context of the present disclosure, bictegravir sodium and succinic acid are dissolved in a mixture of water and organic solvent at elevated temperature, preferably of about 80-90 °C.

Within the context of this embodiment of the present invention, the organic solvent employed may include, polar aprotic solvents such as dimethylformamide, dimethyl sulfoxide, dimethylacetamide or mixtures thereof. In particular useful embodiments of the present invention organic solvent is dimethyl sulfoxide.

Within the context of this embodiment of the present invention, isolation can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation. In particular useful embodiments of the present invention the solid is isolated by filtration followed by washing and drying.

In another aspect the present invention provides crystalline bictegravir Form M3.

Within the context of the present invention, crystalline bictegravir Form M3 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.25, 10.50, 14.22 and 16.47 ± 0.2°. In another embodiments, crystalline bictegravir Form M3 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.25, 6.52, 9.89, 10.50, 10.78, 12.35, 12.99, 13.48, 13.77, 14.22, 14.64, 15.80, 16.13, 16.47, 16.80, 17.26, 17.85, 18.53, 18.93, 19.35, 20.07, 20.49, 20.85, 21.26, 21.46, 21.93, 22.46, 23.10, 23.36, 23.69, 24.05, 24.48, 24.85, 25.27, 25.56, 26.19, 26.59, 27.23, 28.22, 29.57, 30.36, 30.83, 31.21, 31.52, 31.95, 32.81, 34.06, 35.15, 35.74, 36.74, 37.46, 38.08, 38.42, 38.92, 39.61, 40.31, 41.50, 42.46, 43.06, 44.06, 45.04, 46.74, 47.35, 48.30 and 48.78 ± 0.2°.

Another aspect of the present invention provides a process for the preparation of crystalline bictegravir Form M3 comprising the steps of:
a) dissolving bictegravir sodium and oxalic acid in a mixture of water and polar aprotic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M3.

According to the present disclosure, bictegravir sodium and oxalic acid are dissolved in a mixture of water and polar aprotic solvent at elevated temperature. The reaction mass is cooled and stirred to produce a solid. The obtained solid may then filtered and dried to get crystalline bictegravir Form M3.

Within the context of the present disclosure, bictegravir sodium and oxalic acid are dissolved in a mixture of water and organic solvent at elevated temperature, preferably of about 80-90 °C.

Within the context of this embodiment of the present invention, the polar aprotic solvent employed may include, dimethylformamide, dimethyl sulfoxide, dimethylacetamide or mixtures thereof. In particular useful embodiments of the present invention organic solvent is dimethyl sulfoxide.

Within the context of this embodiment of the present invention, isolation can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation. In particular useful embodiments of the present invention the solid is isolated by filtration followed by washing and drying.

In another aspect, the present invention provides crystalline bictegravir Form M4.

Within the context of the present invention, crystalline bictegravir Form M4 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.46, 6.07, 10.55 and 16.22 ± 0.2°. In another embodiments, crystalline bictegravir Form M4 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.46, 6.07, 6.54, 6.99, 8.51, 10.03, 10.55, 10.87, 11.86, 12.33, 12.76, 13.11, 13.52, 14.24, 14.64, 14.95, 15.13, 15.45, 15.95, 16.22, 16.48, 17.07, 17.31, 17.66, 18.17, 18.64, 18.93, 19.22, 19.53, 19.89, 20.87, 21.46, 22.02, 22.26, 22.57, 23.10, 24.03, 24.56, 25.26, 25.73, 26.22, 26.80, 27.23, 27.52, 28.23, 28.97, 29.25, 29.57, 30.09, 30.76, 31.16, 32.66, 34.09, 35.33, 36.13, 36.79, 37.11, 38.90, 39.71, 40.28, 40.72, 41.52, 42.45, 43.12, 43.78, 44.52, 45.96, 46.61, 47.23 and 48.00 ± 0.2°.

Another aspect of the present invention provides a process for the preparation of crystalline bictegravir Form M4 comprising the steps of:
a) dissolving bictegravir sodium and oxalic acid in a mixture of water and alcohol solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M4.

According to the present disclosure, bictegravir sodium and oxalic acid are dissolved in a mixture of water and alcohol solvent at elevated temperature. The reaction mass is cooled and stirred to produce a solid. The obtained solid may then filtered and dried to get crystalline bictegravir Form M4.

Within the context of the present disclosure, bictegravir sodium and oxalic acid are dissolved in a mixture of water and alcohol solvent at elevated temperature, preferably of about 80-90 °C.
Within the context of this embodiment of the present invention, the alcohol solvent employed may include, methanol, ethanol, isopropanol or mixtures thereof. In particular useful embodiments of the present invention organic solvent is methanol.

Within the context of this embodiment of the present invention, isolation can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation. In particular useful embodiments of the present invention the solid is isolated by filtration followed by washing and drying.

In another aspect, the present invention provides crystalline bictegravir Form M5.

Within the context of the present invention, crystalline bictegravir Form M5 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.12, 6.33, 10.35 and 17.59 ± 0.2°. In another embodiment, crystalline bictegravir Form M5 may be characterized by a PXRD pattern having significant peaks at 2? angle positions at about 5.12, 6.33, 9.68, 10.35, 10.71, 12.74, 14.34, 16.57, 17.59, 18.55, 19.01, 19.81, 21.61, 23.05, 23.68, 24.13, 24.91, 25.81, 26.95, 27.74, 28.55, 31.67, 32.77, 35.68, 37.09 and 38.60 ± 0.2°.

Another aspect of the present invention provides a process for the preparation of crystalline bictegravir Form M5 comprising drying the crystalline bictegravir Form M3 at 160-200 °C.

In another aspect, the present invention provides amorphous bictegravir sodium.

Another aspect of the present invention provides a process for the preparation of amorphous bictegravir sodium, which comprises:
a) dissolving bictegravir sodium in a solvent; and
b) removing the solvent and isolating the amorphous bictegravir sodium.

Within the context of this embodiment of the present invention, the solvent employed may include, water and water miscible organic solvents such as acetone, acetonitrile 1,4-dioxane, tetrahydrofuran (THF), diglyme, methanol, ethanol, propanol, dimethyl formamide, ethylene glycol or mixtures thereof. In particular useful embodiments of the present invention solvent is a mixture of 1,4-dioxane and water or a mixture of acetonitrile and water or a mixture of THF and water.

Within the context of this embodiment of the present invention, removing of solvent can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation, lyophilization, spray drying. In particular useful embodiments of the present invention the solvent is removed by lyophilization or spray drying.

In another aspect the present invention is to provide amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers.

Another aspect of the present invention is to provide a process for the preparation of amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers, which comprises:
a) dissolving bictegravir sodium in a solvent;
b) adding pharmaceutically acceptable carrier to the solution obtained in step (a);
c) removing the solvent and isolating the amorphous solid dispersion of bictegravir sodium.

Within the context of this embodiment of the present invention, the solvent employed may include, water and water miscible organic solvents such as acetone, acetonitrile 1,4-dioxane, diglyme, methanol, ethanol, propanol, dimethyl formamide, ethylene glycol or mixtures thereof. In particular useful embodiments of the present invention solvent is a mixture of 1,4-dioxane and water or a mixture of acetonitrile and water.

Within the context of this embodiment of the present invention, pharmaceutically acceptable carrier employed may include, povidone, copovidone, silicon dioxide, microcrystalline cellulose or mixtures thereof. Said povidone is selected from povidone K-17, povidone K-25, povidone K-30 and the like; said copovidone is selected from such as copovidones of which the brand names are Plasdone S-630 or Kollidon VA64 and the like. In particular useful embodiments of the present invention pharmaceutically acceptable carrier selected is silicon dioxide or microcrystalline cellulose.

Within the context of this embodiment of the present invention, removing of solvent can be done using any techniques in the art such as, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation, lyophilization. In particular useful embodiments of the present invention the solvent is removed by lyophilization.

Another aspect of the present invention is to provide a process for the preparation of amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carriers, which comprises:
a) dissolving bictegravir sodium and pharmaceutically acceptable carrier in a solvent; and
b) removing the solvent and isolating the amorphous solid dispersion of bictegravir sodium.

Within the context of this embodiment of the present invention, the solvent employed may include, water and water miscible organic solvents such as acetone, acetonitrile tetrahydrofuran (THF), diglyme, methanol, ethanol, propanol, dimethyl formamide, ethylene glycol or mixtures thereof. In particular useful embodiments of the present invention solvent is a mixture of THF and water.

Within the context of this embodiment of the present invention, pharmaceutically acceptable carrier employed may include, povidone, copovidone, silicon dioxide, hydroxypropyl methylcellulose (HPMC), microcrystalline cellulose or mixtures thereof. Said povidone is selected from povidone K-17, povidone K-25, povidone K-30 and the like; said copovidone is selected from such as copovidones of which the brand names are Plasdone S-630 or Kollidon VA64 and the like. In particular useful embodiments of the present invention pharmaceutically acceptable carrier selected is Plasdone S-630 or hydroxypropyl methylcellulose (HPMC).

Within the context of this embodiment of the present invention, removing of solvent can be done using any techniques in the art such as, spray drying, decantation, filtration by gravity or suction, centrifugation, slow evaporation, distillation. In particular useful embodiments of the present invention the solvent is removed by spray drying.

According to the present invention, the input bictegravir sodium is prepared by any prior-art process for example PCT publication No. WO2015196116A1.

Crystalline bictegravir Form M1, Form M2, amorphous form of bictegravir sodium and amorphous solid dispersion of bictegravir sodium with 50% Plasdone S-630 and 50% HPMC disclosed herein may exhibit enhanced stability during storage. Thus, the samples of crystalline bictegravir Form M1, Form M2, amorphous form of bictegravir sodium and amorphous solid dispersion of bictegravir sodium were stored at 40 °C/75% relative humidity (RH) and at 25 °C/60% relative humidity (RH) for 6 months. The samples were analyzed by PXRD for polymorph integrity.

Results of this testing revealed that crystalline bictegravir Form M1, Form M2 and amorphous bictegravir sodium shows no change in PXRD pattern and HPLC purity when stored for 6 months at 40°C and 75% relative humidity (RH) and at 25°C and 60% relative humidity (RH) conditions as mentioned in below Table 1.

Table 1
Conditions/ Polymorph Bictegravir
Form M1 Bictegravir
Form M2 Bictegravir Sodium
Amorphous form
PXRD HPLC purity PXRD HPLC purity PXRD HPLC purity
at 40°C/75% RH
Initial Crystalline 99.66 Crystalline 99.68 Amorphous from 99.48
1 months Stable 99.67 Stable 99.67 Stable 99.68
2 months Stable 99.69 Stable 99.69 Stable 99.54
3 months Stable 99.80 Stable 99.73 Stable 99.48
6 months Stable 99.78 Stable 99.71 Stable 99.31
at 25°C/60% RH
Initial Crystalline 99.66 Crystalline 99.68 Amorphous from 99.48
1 months Stable 99.68 Stable 99.68 Stable 99.68
2 months Stable 99.67 Stable 99.67 Stable 99.52
3 months Stable 99.73 Stable 99.73 Stable 99.54
6 months Stable 99.73 Stable 99.73 Stable 99.46

Amorphous solid dispersion of Bictegravir Sodium with 50% Plasdone S-630 shows no change in PXRD pattern and HPLC purity when stored for 6 months at 40°C and 75% relative humidity (RH) and at 25°C and 60% relative humidity (RH) conditions as mentioned in below Table 2.
Table 2
Conditions/ Polymorph Amorphous solid dispersion of Bictegravir with 50% Plasdone S-630
PXRD HPLC purity
at 40°C/75% RH
Initial Amorphous form 99.44
1 months Stable 99.66
2 months Stable 99.52
3 months Stable 99.44
6 months Stable 99.43
at 25°C/60% RH
Initial Amorphous form 99.44
1 months Stable 99.64
2 months Stable 99.51
3 months Stable 99.51
6 months Stable 99.44

Amorphous solid dispersion of Bictegravir Sodium with 50% HPMC shows no change in PXRD pattern and HPLC purity when stored for 3 months at 25°C and 60% relative humidity (RH) condition as mentioned in below Table 3.
Table 3
Conditions/ Polymorph Amorphous solid dispersion of Bictegravir Sodium with 50% HPMC
PXRD HPLC purity
at 25°C/60% RH
Initial Amorphous form 99.39
1 months Stable 99.48
2 months Stable 99.41
3 months Stable 99.40

Certain specific aspects and embodiments of the present application will be explained in greater detail with reference to the following examples, which are provided only for purposes of illustration and should not be construed as limiting the scope of the disclosure in any manner. Reasonable variations of the described procedures are intended to be within the scope of the present application. While particular aspects of the present application have been illustrated and described, it would be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to encompass all such changes and modifications that are within the scope of this disclosure.
EXAMPLES
Example 1: Preparation of crystalline bictegravir Form M1:

Bictegravir Sodium (5 g) and fumaric acid (1.23 g) were dissolved in a mixture of dimethyl sulfoxide (60 mL) and water (20 mL) at 85±5°C. The reaction mass was cooled to 25±5 °C and maintained under stirring at 25±5 °C for 15 hours. The product obtained was filtered, washed with water (10mL) and dried under vacuum at 50 °C for 13 hours. The solid obtained was identified as crystalline bictegravir Form M1.
Yield: 3.8g

Example 2: Preparation of crystalline bictegravir Form M2:

Bictegravir Sodium (5 g) and succinic acid (1.25 g) were dissolved in a mixture of dimethyl sulfoxide (62.5 mL) and water (25 mL) at 85±5°C. The reaction mass was cooled to 25±5 °C and maintained under stirring at 25±5 °C for 15 hours. The product obtained was filtered and dried under vacuum at 50 °C for 13 hours. The solid obtained was identified as crystalline bictegravir Form M2.
Yield: 3.8g

Example 3: Preparation of crystalline bictegravir Form M3:

Bictegravir Sodium (0.2 g) and oxalic acid (53.5 mg) were dissolved in a mixture of dimethyl sulfoxide (3 mL) and water (1 mL) at 85±5 °C. The reaction mass was cooled to 25±5 °C and maintained under stirring at 25±5 °C for 24 hours. The product obtained was filtered and suck-dried. The solid obtained was identified as crystalline bictegravir Form M3.
Yield: 0.15g

Example 4: Preparation of crystalline bictegravir Form M4:

Bictegravir Sodium (0.5 g) and oxalic acid (134 mg) were dissolved in a mixture of methanol (12.5 mL) and water (12.5 mL) at 80±5 °C. The reaction mass was cooled to 25±5 °C and maintained under stirring for 24 hours. The product obtained was filtered and dried under vacuum at 50 °C for 2 hours. The solid obtained was identified as crystalline bictegravir Form M4.
Yield: 0.4g

Example 5: Preparation of crystalline bictegravir Form M5:

Bictegravir Form M3 (0.2 g) was heated up to 180 °C using variable temperature powder XRD tool on Bruker D8 X-Ray Diffractometer. The resulting solid was identified as crystalline bictegravir Form M5.

Example 6: Preparation of amorphous bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of acetonitrile (30 mL) and water (30 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and subjected to lyophilisation using Labocon lyophilizer to yield amorphous bictegravir sodium.

Example 7: Preparation of amorphous bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of 1,4-dioxane (30 mL) and water (30 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and subjected to lyophilisation using Labocon lyophilizer to yield amorphous bictegravir sodium.

Example 8: Preparation of amorphous bictegravir sodium:

Bictegravir Sodium (5 g) was dissolved in a mixture of tetrahydrofuran (350 mL) and water (150 mL) at 70±5°C. The resulting clear solution was filtered to remove any undissolved particulates and subjected to spray-drying in a laboratory spray-dryer (Model: Buchi B-290) with feed rate of solution 5 mL/min and inlet temperature at 80°C with 100% aspiration to yield amorphous bictegravir sodium.

Example 9: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of 1,4-dioxane (28 mL) and water (25 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and added Silicon dioxide (0.25 g) and subjected to lyophilisation using Labocon lyophilizer to yield amorphous solid dispersion of bictegravir sodium.

Example 10: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of acetonitrile (28 mL) and water (25 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and added Silicon dioxide (0.25 g) and subjected to lyophilisation using Labocon lyophilizer to yield amorphous solid dispersion of bictegravir sodium.

Example 11: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of 1,4-dioxane (30 mL) and water (30 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and added Microcrystalline cellulose (0.25 g) and subjected to Lyophilisation using Labocon lyophilizer to yield amorphous solid dispersion of bictegravir sodium.

Example 12: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (0.25 g) was dissolved in a mixture of acetonitrile (30 mL) and water (30 mL) at 85±5°C. The resulting clear solution was filtered to remove any undissolved particulates and added Microcrystalline cellulose (0.25 g) and subjected to Lyophilisation using Labocon lyophilizer to yield amorphous solid dispersion of bictegravir sodium.

Example 13: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (4 g) and Plasdone S-630 (4 g) were dissolved in a mixture of tetrahydrofuran (280 mL) and water (120 mL) at 70±5°C. The resulting clear solution was filtered to remove any undissolved particulates and subjected to spray-drying in a laboratory spray-dryer (Model: Buchi B-290) with feed rate of solution 5 mL/min and inlet temperature at 80°C with 100% aspiration to yield amorphous solid dispersion of bictegravir sodium.

Example 14: Preparation of amorphous solid dispersion of bictegravir sodium:

Bictegravir Sodium (5 g) and HPMC (5 g) were dissolved in a mixture of tetrahydrofuran (370 mL) and water (140 mL) at 70±5°C. The resulting clear solution was filtered to remove any undissolved particulates and subjected to spray-drying in a laboratory spray-dryer (Model: Buchi B-290) with feed rate of solution 5 mL/min and inlet temperature at 80°C with 100% aspiration to yield amorphous solid dispersion of bictegravir sodium.

,CLAIMS:We Claim:
1. A crystalline bictegravir Form M1, which has a powder X-ray diffraction pattern having significant peaks at 2? angles positions at about 5.23, 10.50, 15.79 and 17.84 ± 0.2° and characterized by a PXRD pattern as shown in Figure 1.
2. A process for the preparation of crystalline bictegravir Form M1, comprising the steps of:
a) dissolving bictegravir sodium and fumaric acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M1.

3. A crystalline bictegravir Form M2, which has a powder X-ray diffraction pattern having significant peaks at 2? angles positions at about 5.27, 10.54, 14.25, and 15.83 ± 0.2° and characterized by a PXRD pattern as shown in Figure 2.
4. A process for the preparation of crystalline bictegravir Form M2, comprising the steps of:
a) dissolving bictegravir sodium and succinic acid in a mixture of water and organic solvent at elevated temperature;
b) cooling the reaction mass to 20-35 °C;
c) stirring the reaction mass to form the precipitation; and
d) isolating crystalline bictegravir Form M2.

5. The process as claimed in claims 2 and 4, wherein the organic solvent is selected from the group consisting of dimethylformamide, dimethyl sulfoxide, dimethylacetamide or mixtures thereof.
6. Amorphous bictegravir sodium.
7. A process for the preparation of amorphous bictegravir sodium, which comprising the steps of:
a) dissolving bictegravir sodium in a solvent; and
b) removing the solvent and isolating the amorphous bictegravir sodium.
wherein the solvent is selected from the group consisting of water and water miscible organic solvents such as acetone, acetonitrile 1,4-dioxane, diglyme, methanol, ethanol, propanol, dimethylformamide, ethylene glycol or mixtures thereof.

8. Amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carrier.
9. A process for the preparation of amorphous solid dispersion of bictegravir sodium with pharmaceutically acceptable carrier, comprising the steps of:
a) dissolving bictegravir sodium and pharmaceutically acceptable carrier in a solvent; and
b) removing the solvent and isolating the amorphous solid dispersion of bictegravir sodium.
wherein the solvent is selected from the group consisting of water and water miscible organic solvents such as acetone, acetonitrile 1,4-dioxane, diglyme, methanol, ethanol, propanol, dimethylformamide, ethylene glycol or mixtures thereof.