PREPARATION OF LATANOPROSTENE BUNOD OF DESIRED, PRE-DEFINED QUALITY BY GRAVITY CHROMATOGRAPHY

Abstract

The subject of the invention is a process for the preparation of Latanoprostene bunod of formula (I) with a purity higher than 95% where chromatography is used applying normal phase gravity silica gel column chromatography where the used silica gel is irregular silica gel or spherical silica gel an as eluent and eluent mixture consisting of an apolar and a polar solvent is used and if desired, contamination of the purified compound of formula I arising from the solvents are removed by silica gel filtration chromatography.

Claims

1. Process for the preparation of Latanoprostene bunod of formula (I) with a purity higher than 95% ##STR00007## characterized in that the crude Latanoprostene bunod of formula (I) is purified by chromatography, applying normal phase gravity silica gel column chromatography, using as silica gel a.) normal phase, irregular silica gel of particle size 63-200 micron, or b.) normal phase spherical silica gel of particle size 50-150 micron, and as eluent, an eluent mixture consisting of an apolar and a polar solvent, and if desired, impurities arising from the eluents used for purification chromatography of compound of formula (I) are removed by silica gel filtration chromatography.

2. Process a.) or b.) as defined in claim 1, characterized in that, the eluent mixture contains as apolar solvent straight- or branched-chain aliphatic, cyclic or aromatic hydrocarbons, halogenated aliphatic hydrocarbons or ether-type solvents.

3. Process as defined in claim 2, characterized in that, as apolar solvent pentane, hexane, heptane, cyclohexane, dichloromethane or diisopropyl ether, preferably hexane is applied.

4. Process a.) or b.) as defined in claim 1, characterized in that, as polar solvent an alcohol-, ester- or ketone-type solvent containing straight- or branched-chain alkyl group is applied.

5. Process as defined in claim 4, characterized in that, as polar solvent a C1-5 alcohol, preferably ethyl alcohol or isopropyl alcohol is applied.

6. Process as defined in claim 3, characterized in that, the eluent mixture is a gradient mixture containing hexane and ethyl alcohol in 6:1-8:1 volume ratios.

7. Process as defined in claim 4, characterized in that, as polar solvent a ketone-type solvent, preferably acetone is applied.

8. Process as defined in claim 3, characterized in that, the eluent mixture contains hexane and acetone in 2:1 volume ratio.

9. Filtration chromatography process as defined in claim 1, characterized in that, the eluent mixture contains an apolar and a polar solvent.

10. Process as defined in claim 9, characterized in that, the eluent mixture contains as apolar solvent an optionally halogen-substituted straight or branched open-chain, or cyclic or aromatic hydrocarbon.

11. Process as defined in claim 9, characterized in that, the eluent mixture contains as polar solvent an alcohol-, ether-, ester- or ketone-type solvent containing straight or branched open-chain or cyclic alkyl or cycloalkyl group.

12. Process as defined in claim 11, characterized in that, the eluent mixture contains dichloromethane and ethyl acetate in 2:1 volume ratio.

13. High purity Latanoprostene bunod of formula (I) which meets following quality requirements: TABLE-US-00023 Latanoprostene Bunod Related impurities (HPLC) 15S-Latanoprostene bunod 0.15% 5,6-trans-Latanoprostene bunod 0.50% Latanoprost 0.10% Latanoprost acid 0.10% Non-identified impurities individually 0.10% Non-identified impurities, total 0.30% Sum of impurities 0.80%.

14. Pure Latanoprostene bunod of formula (I) which meets the following quality requirements: TABLE-US-00024 Latanoprostene bunod Related impurities (HPLC) 15S-Latanoprostene bunod 0.50% 5,6-trans-Latanoprostene bunod 3.5% Latanoprost 0.50 Latanoprost acid 0.50% Non-identified impurities individually 0.10% Non-identified impurities, total 0.30% Sum of impurities 5.0%.

15. Process as defined in claim 5, characterized in that, the eluent mixture is a gradient mixture containing hexane and ethyl alcohol in 6:1-8:1 volume ratios.

16. Process as defined in claim 7, characterized in that, the eluent mixture contains hexane and acetone in 2:1 volume ratio.

17. Process as defined in claim 12, characterized in that, the eluent mixture contains dichloromethane and ethyl acetate in 2:1 volume ratio.

Description

EXAMPLES

1. Example

Purification of Latanoprostene Bunod

4-nitrooxybutyl (Z)-7-[(1R,2R,3R,5S)-3,5-dihydroxy-2-[(3R)-3-hydroxy-5-phenyl-pentyl]cyclopentyl]hept-5-enoate

[0073] 461.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. The solution is purified by gravity chromatography on a column packed with 100-fold amount (counted for the crude product) of 60 Angstrom pore diameter, 63-200 micron particle size irregular silica gel, using hexane:ethanol=8:1-6:1 eluent mixture. The fractions of appropriate purity are united and evaporated. Yield: 401.1 g (87%). Impurities of the product arising from the eluents used for purification chromatography are removed by filtration chromatography. For dissolution dichloromethane:ethyl acetate mixture is used. The solution is purified by gravity chromatography on a column packed with 10-fold amount (counted for the evaporated product) of 60 Angstrm pore diameter, 63-200 micron particle size irregular silica gel, using dichloromethane:ethyl acetate=2:1 eluent mixture. The tractions of appropriate purity are united and evaporated. Yield: 364.9 g (91%).

Improvement of the Quality of Latanoprostene Bunod During Purification (HPLC Area %):

[0074]

TABLE-US-00006 Purification Filtration Impurities Crude chroma- chroma- (HPLC area %) product tography tography RRT = 0.33 23.31% 0.11% 0.00% RRT = 0.70 0.08% 0.00% 0.00% (Latanoprost) RRT = 0.81 0.14% 0.00% 0.00% (Latanoprost acid) 15S-Latanoprostene bunod 0.11% 0.08% 0.08% Latanoprostene bunod 72.69% 96.65% 97.52% 5,6-trans- 2.03% 2.25% 2.27% Latanoprostene bunod RRT = 1.46 1.30% 0.07% 0.09% Other impurities, total 0.34% 0.84% 0.04%

2. Example

[0075] 50.0 g of crude Latanoprostene bunod is dissolved in toluene. Hexane:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 5000 g of 75 micron particle size, 60 Angstrm pore diameter YMC spherical silica gel, using hexane:acetone=2:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 38.0 g (76%).

TABLE-US-00007 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.09% Latanoprostene bunod 72.88% 99.70% 5,6-trans-Latanoprostene bunod 2.03% 0.13% RRT = 1.46 1.24% 0.08% other impurities, total 0.34% 0.00%

3. Example

[0076] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Diisopropyl ether:methanol mixture is added and the solution is purified by gravity chromatography on a column packed with 25 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel using diisopropyl ether:methanol gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.704 g (70%).

TABLE-US-00008 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 1.09% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.16% Latanoprostene bunod 72.88% 95.69% 5,6-trans-Latanoprostene bunod 2.03% 2.82% RRT = 1.46 1.24% 0.16% other impurities, total 0.34% 0.08%

4. Example

[0077] 1.0 g of crude Latanoprostene bunod is dissolved in toluene. Hexane:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 50 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:acetone=2:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.55 g (55%).

TABLE-US-00009 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.43% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.13% Latanoprostene bunod 72.88% 97.42% 5,6-trans-Latanoprostene bunod 2.03% 1.06% RRT = 1.46 1.24% 0.86% other impurities, total 0.34% 0.10%

5. Example

[0078] 1.0 g of crude Latanoprostene bunod is dissolved in toluene. Hexane:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:acetone=2:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.51 g (51%).

TABLE-US-00010 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.17% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.13% Latanoprostene bunod 72.88% 98.47% 5,6-trans-Latanoprostene bunod 2.03% 0.61% RRT = 1.46 1.24% 0.52% other impurities, total 0.34% 0.10%

6. Example

[0079] 1.0 of crude Latanoprostene bunod is dissolved in toluene. Hexane:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 75 micron particle size, 60 Angstrm pore diameter YMC spherical silica gel, using hexane:acetone=2:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.74 g (74%).

TABLE-US-00011 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.08% Latanoprostene bunod 72.88% 99.71% 5,6-trans-Latanoprostene bunod 2.03% 0.12% RRT = 1.46 1.24% 0.09% other impurities, total 0.34% 0.00%

7. Example

[0080] 1.0 of crude Latanoprostene bunod is dissolved in toluene. Hexane:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 75 micron particle size, 60 Angstrm pore diameter YMC spherical silica gel, using hexane:acetone=3:2 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.61 g (61%).

TABLE-US-00012 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.12% Latanoprostene bunod 72.88% 99.40% 5,6-trans-Latanoprostene bunod 2.03% 0.29% RRT = 1.46 1.24% 0.19% other impurities, total 0.34% 0.00%

8. Example

[0081] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Diisopropyl ether:acetone mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using diisopropyl ether:acetone gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.47 g (47%).

TABLE-US-00013 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.13% Latanoprostene bunod 72.88% 98.57% 5,6-trans-Latanoprostene bunod 2.03% 0.70% RRT = 1.46 1.24% 0.49% other impurities, total 0.34% 0.11%

9. Example

[0082] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:isopropanol mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:isopropanol=5:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.56 g (56%).

TABLE-US-00014 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.15% Latanoprostene bunod 72.88% 96.64% 5,6-trans-Latanoprostene bunod 2.03% 2.73% RRT = 1.46 1.24% 0.40% other impurities, total 0.34% 0.08%

10. Example

[0083] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:ethanol=8:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.52 g (52%).

TABLE-US-00015 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.12% Latanoprostene bunod 72.88% 98.99% 5,6-trans-Latanoprostene bunod 2.03% 0.66% RRT = 1.46 1.24% 0.12% other impurities, total 0.34% 0.11%

11. Example

[0084] 1.0 of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 75 micron particle size, 60 Angstrm pore diameter YMC spherical silica gel, using hexane:ethanol=6:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.57 g (57%).

TABLE-US-00016 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.12% Latanoprostene bunod 72.88% 99.30% 5,6-trans-Latanoprostene bunod 2.03% 0.33% RRT = 1.46 1.24% 0.25% other impurities, total 0.34% 0.00%

12. Example

[0085] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on a column packed with 25 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:ethanol gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.64 g (64%).

TABLE-US-00017 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 1.12% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.17% Latanoprostene bunod 72.88% 95.45% 5,6-trans-Latanoprostene bunod 2.03% 2.80% RRT = 1.46 1.24% 0.36% other impurities, total 0.34% 0.10%

13. Example

[0086] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on a column packed with 50 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:ethanol gradient mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.75 g (75%).

TABLE-US-00018 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.17% Latanoprostene bunod 72.88% 96.67% 5,6-trans-Latanoprostene bunod 2.03% 2.87% RRT = 1.46 1.24% 0.21% other impurities, total 0.34% 0.08%

14. Example

[0087] 1.0 of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on a column packed with 100 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using hexane:ethanol gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.92 g (92%).

TABLE-US-00019 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.16% Latanoprostene bunod 72.88% 96.88% 5,6-trans-Latanoprostene bunod 2.03% 2.80% RRT = 1.46 1.24% 0.08% other impurities, total 0.34% 0.08%

15. Example

[0088] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on column packed with 100 g of 63-200 micron particle size 60 Angstrm pore diameter irregular silica gel, using hexane:ethanol gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.83 g (83%).

TABLE-US-00020 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.17% Latanoprostene bunod 72.88% 97.23% 5,6-trans-Latanoprostene bunod 2.03% 2.53% RRT = 1.46 1.24% 0.00% other impurities, total 0.34% 0.07%

16. Example

[0089] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. Hexane:ethanol mixture is added and the solution is purified by gravity chromatography on column packed with 100 g of 75 micron particle size, 60 Angstrm pore diameter YMC spherical silica gel, using hexane:ethanol=6:1 mixture eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.48 g (48%).

TABLE-US-00021 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.12% Latanoprostene bunod 72.88% 99.34% 5,6-trans-Latanoprostene bunod 2.03% 0.47% RRT = 1.46 1.24% 0.06% other impurities, total 0.34% 0.01%

17. Example

[0090] 1.0 g of crude Latanoprostene bunod is dissolved in dichloromethane. The solution is purified by gravity chromatography on a column packed with 10 g of 63-200 micron particle size, 60 Angstrm pore diameter irregular silica gel, using dichloromethane:ethyl acetate gradient mixtures as eluent. The fractions of appropriate purity are united and evaporated. Yield: 0.75 g (75%).

TABLE-US-00022 Purification Impurities (HPLC area %) Crude product chromatography RRT = 0.33 23.31% 0.00% RRT = 0.70 (Latanoprost) 0.09% 0.00% RRT = 0.81 (Latanoprost acid) 0.00% 0.00% 15S-Latanoprostene bunod 0.11% 0.17% Latanoprostene bunod 72.88% 96.36% 5,6-trans-Latanoprostene bunod 2.03% 2.73% RRT = 1.46 1.24% 0.65% other impurities, total 0.34% 0.09%

[0091] The HPLC procedure used in all above Examples is a stability indicating isocratic normal-phase HPLC assay method which also quantitates the related substances of Latanoprostene bunod in the drug substance. Measurement conditions are the followings:

Assay (HPLC)

Instruments

[0092] Instrument: Isocratic HPLC system equipped with UV or diode array detector, electronic data management system and autosampler. [0093] Column: Kromasil 60 5SIL; 2504.6 mm, 5 m or equivalent

Chromatographic Conditions

[0094] Eluent n-hexane:ethanol:ispropanol:acetic acid=930:5:35:1

Detection: 210 nm

[0095] Flow rate: 2 ml/min
Injected amount 10 l
Column temperature: 35 C.
Run time: 25 min