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The present invention relates to novel hydrates of sodium dolutegravir and their methods of preparation. In addition, the invention relates to a novel crystalline form of sodium dolutegravir, which is a useful intermediate for the preparation of one of the new hydrates. The invention also relates to the use of the new hydrates for the production of pharmaceutical compositions.
Finally, the invention relates to pharmaceutical compositions comprising an effective amount of the novel hydrates, oral dosage forms comprising these pharmaceutical compositions, a process for preparing said oral dosage forms, and the use of such pharmaceutical compositions or dosage forms in the treatment of retroviral infections such as HIV infections -1.
Dolutegravir, chemically designated (4f?, 12aS)-/V-(2,4-difluorobenzyl)-7-hydroxy-4-methyl-6,8-dioxo-3,4,6,8, 12, 12a-hexahydro-2H-pyrido[1 ',2':4,5]pyrazino[2, 1- ?][1 ,3]oxazine-9-carboxamide, is a human immunodeficiency virus type 1 (HIV-1 ) integrase strand transfer inhibitor (INSTI) indicated in combination with other a nti retroviral agents for the treatment of HIV-1 infection. The marketed finished dosage form (TIVICAY™) contains dolutegravir as its sodium salt, chemically denominated sodium (4f?,12aS)-9-((2,4-difluorobenzyl)carbamoyl)-4-methyl-6,8-dioxo-3,4,6,8,12, 12a-hexahydro-2H-pyrido[1 ',2':4,5]pyrazino[2, 1- ?][1 ,3]oxazin-7-olate, which is represented by the following general chemical formula (I):
WO 2010/068253 A1 discloses a monohydrate and an anhydrous form of dolutegravir sodium as well as a crystalline form of the free compound. Processes for the preparation of said forms are also provided in the application.
WO 2013/038407 A1 discloses amorphous dolutegravir sodium and processes for preparing the same.
Hydrates of pharmaceutical drug substances are of particular interest as they provide new opportunities for preparing novel pharmaceutical compositions with improved quality, activity and/or compliance. This is due to the fact that hydrates have different physicochemical properties compared to their anhydrous counterparts such as melting point, density, habitus, chemical and physical stability, hygroscopicity, dissolution rate, solubility, bioavailability etc., which influence the formulation process and also impact the final drug product.
If an anhydrous form is selected, phase changes during the formulation process induced by hydrate formation must be avoided. This can be particularly difficult if for example wet granulation is used with a substance that is able to form hydrates like dolutegravir sodium.
Hence, a stable hydrate of dolutegravir sodium would allow to easily formulate dolutegravir sodium in a controlled manner and subsequently also facilitate storage and packaging.
However, the so far known dolutegravir sodium monohydrate disclosed in WO 2010/068253 A1 shows excessive water uptake when exposed to moisture and on the other hand already dehydrates below 30% relative humidity.
Therefore, there is a need for hydrates of dolutegravir sodium with improved physicochemical properties, e.g. for hydrates which are stable over a broad humidity range, in particular for hydrates absorbing only low amounts of water at elevated humidity and on the other hand preserving their crystal structure also at dry conditions. In addition, there is a need for pharmaceutical compositions comprising these hydrates, and thus also for hydrates that allow for improved formulation of dolutegravir sodium in pharmaceutical compositions.
SUMMARY OF THE INVENTION
The present invention relates to novel hydrates of dolutegravir sodium and to processes for their preparation. Specifically, the present invention provides crystalline forms of dolutegravir sodium of formula (I) according to respective claims 1 , 5 and 6, with preferred embodiments being set forth in sub-claim 2. The present invention also provides processes for their preparation according to respective claims 3, 7 and 8, with preferred process embodiments being set forth in sub-claim 4. The present invention further provides the uses according to claims 9 and 16, and a pharmaceutical composition according to claim 10, and preferred embodiments thereof according to sub-claims 1 1 and 12. The present invention also provides a process for the preparation of the pharmaceutical composition according to claim
13, and preferred embodiments thereof according to sub-claim 14. The pharmaceutical composition for therapeutic use is set forth in claim 15.
The novel hydrates are physically and chemically stable over a broad humidity range, show only low water uptakes when exposed to moisture and are even stable at dry conditions. Therefore, the novel hydrates are especially suitable for the preparation of pharmaceutical compositions, e.g. in terms of time and costs.
In particular, it has been found that crystal Form HxA exhibits improved properties which allow for improved formulation of Form HxA in pharmaceutical compositions.
In addition, the present invention relates to a novel crystalline form of dolutegravir sodium, which, for the first time, allows the preparation of one of the novel hydrates and is therefore a valuable intermediate.
WO2016016279, NEW PATENT, DOLUTEGRAVIR SODIUM, LEK PHARMACEUTICALS D.D. , SANDOZ AG