Article pubs.acs.org/OPRD
Effect of Temperature and Solvent of Solvent-Mediated Polymorph Transformation on ASP3026 Polymorphs and Scale-up Kazuhiro Takeguchi,*,†,§ Kazuyoshi Obitsu,† Shun Hirasawa,† Ryoki Orii,† Shigeru Ieda,‡ Minoru Okada,† and Hiroshi Takiyama§ †
Technology Process Chemistry Laboratories, Astellas Pharma Inc., 160-2 Akahama, Takahagi, Ibaraki 318-0001, Japan Astellas Pharma Tech Co., Ltd., 160-2 Akahama, Takahagi, Ibaraki 318-0001, Japan § Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan ‡
ABSTRACT: ASP3026 (N-{2-methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}-N′-[2-(propane-2-sulfonyl)phenyl]-1,3,5-triazine-2,4-diamine) was developed as a novel and selective inhibitor of the fusion protein EML4-ALK. Five polymorphs of ASP3026 (A01, A02, A03, A04, and A05) as well as a hydrate have been identified to date. Process development was conducted for large-scale pilot plant manufacturing, and obtaining the desired polymorph A04 was key after a synthetic route of ASP3026 was selected for scale-up. The effects of temperature and solvent species on induction time of polymorph transformation were investigated using in situ Raman spectroscopy, and selective transformation conditions of A02 to A03 and A04 were examined in detail. A04 was obtained at high temperatures using highly polar non-hydrogen-bond-donating solvents, while A03 was obtained at low temperatures using low-polarity or hydrogen-bond-donating solvents. Further, the desired polymorph A04 was successfully obtained in high purity in first stage scale-up manufacturing. Given these findings, this method of solvent-mediated polymorph transformation may aid in process development for obtaining desired polymorphs.
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INTRODUCTION A compound with two or more crystal structures is called “polymorphic”, and crystalline polymorphism has major effects on solubility, bioavailability, chemical and physical stabilities, and filterability.1−3 The ultimate solid form can significantly influence the final quality attributes of active pharmaceutical ingredients (APIs). As such, the thermodynamic stability evaluation and selective crystallization process development of polymorphs are important for not only API manufacturing but also drug development strategies. ASP3026 (N-{2-methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}-N′-[2-(propane-2-sulfonyl)phenyl]1,3,5-triazine-2,4-diamine) (Figure 1) was developed as a novel
temperature. The most stable polymorph A04 was thus selected for solid formulation design. Process development was conducted for large-scale pilot plant manufacturing, and obtaining the desired polymorph A04 was key after a synthetic route of ASP3026 was selected for scale-up. The relationship between A03 and A04 is monotropic, and A04 is always stable. However, A04 and A03 are examples of concomitant polymorphism, where several polymorphs of one compound nucleate and grow simultaneously.7 As such, the solubility between these two forms does not markedly differ, hampering selective crystallization of A04. Process analytical technology (PAT) involves designing, analyzing, and controlling manufacturing through timely measurements of critical quality and performance attributes of raw materials, intermediates, and products.8 PAT tools such as Fourier transform infrared spectroscopy (FT-IR), near-infrared spectroscopy (NIR), focused beam reflectance measurement (FBRM), and Raman spectroscopy are commonly used to monitor and control processes. In particular, in situ Raman spectroscopy is used extensively for the qualification and quantification of different polymorphs and monitoring of their transformation behavior.9 While a route for synthesizing ASP3026 has been already established in our pilot plant manufacturing study, only the A02 formnot the desired polymorph A04could be reproducibly obtained. Therefore, the solvent-mediated polymorph transformation of A02 to A04 was investigated. Because thermodynamic stability between A03 and A04 was very
Figure 1. ASP3026 structure.
selective inhibitor of the fusion protein EML4-ALK.4 A mixture of A01 and A02 was obtained in early stage development of ASP3026, and five polymorphs (A01, A02, A03, A04, and A05) as well as a hydrate have been identified thus far. Our previous study evaluating the thermodynamic stability of each ASP3026 polymorph5,6 showed that thermodynamic stability decreased in the order of A04, A03, A02, A01, and A05 at ambient © XXXX American Chemical Society
Received: March 4, 2016
A
DOI: 10.1021/acs.oprd.6b00068 Org. Process Res. Dev. XXXX, XXX, XXX−XXX
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Table 1. Solubility and Solvent Property Parameters Hansen solubility parameters, including one-component values12 Σα
a,11
EtOH IPA acetone MEK MIBK AcOEt water
0.37 0.33 0.04 0 0 0 1.17
Σβ
b,11
0.48 0.56 0.49 0.51 0.51 0.45 0.47
π
c,11
dipole moment
0.54 0.48 0.71 0.67 0.65 0.55 1.09
11
dielectric constant
1.69 1.56 2.88 2.78 2.81 1.78 1.87
24.85 19.26 20.49 18.25 12.89 5.99 78.36
11
δd (MPa1/2)
δde (MPa1/2)
δpf (MPa1/2)
δhg (MPa1/2)
26.0 23.5 20.3 19.0 17.2 18.6 47.9
15.8 15.8 15.5 16.0 15.3 15.8 15.5
8.8 6.1 10.4 9.0 6.1 5.3 16.0
19.4 16.4 7.0 5.1 4.1 7.2 42.3
a Summation of the hydrogen bond donor (HBD) propensities of the solvent. bSummation of the hydrogen bond acceptor (HBA) propensities of the solvent. cPolarity/dipolarity (π). dHansen solubility parameter (δ). eDispersion component of δ. fPolar component of δ. gHydrogen bonding component of δ.
Figure 2. Raman spectra of A02, A03, and A04.
performance liquid chromatography (HPLC) (Shimadzu Corp., Kyoto, Japan; or Hitachi High-Tech, Tokyo, Japan) under the following conditions: mobile phase, 0.1% perchloric acid aq. to acetonitrile (3:1); column, L-column 2 ODS (4.6 mm × 150 mm, 5 μm; Chemical Evaluation and Research Institute, Tokyo, Japan), flow rate, 1 mL/min; column temperature, 313 K; and detection, UV 225 nm. Solvent-Mediated Polymorph Transformation Experiments. Solvent-mediated polymorph transformation experiments were performed using the Easy Max 102 basic personal parallel synthesis workstations (Mettler-Toledo, Greifensee, Switzerland), which focused on chemical process optimization at volumes of 0.5−100 mL. Acetone, methyl ethyl ketone (MEK), ethanol (EtOH), isopropyl alcohol (IPA), methyl isobutyl ketone (MIBK), ethyl acetate (AcOEt), 50% acetone− water, and 50% EtOH−water were used in these experiments. A solvent (40 mL) was added to a 100 mL glass reactor, and the agitation rate was set to 200 rpm. Crude ASP3026 (4 g) was added to the reactor after the solvent temperature had been controlled to the predetermined temperature (298 or 323 K). Polymorph transformation was monitored using a Raman Rxn2 785 (Kaiser Optical System, Inc., Ann Arbor MI, USA) equipped with an InvictusTM 785 nm laser at 450 mW. The slurry was filtered after any characteristics peak of A02 was not observed. The precipitated solid was obtained by drying and
similar, the effects of temperature and solvent on the selectivity of A03 and A04 were studied using Raman spectroscopy. The process conditions also established for scale-up manufacturing through experiments using the scaled-down glass reactor of our pilot plant equipment.
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EXPERIMENTAL SECTION Materials. ASP3026 was synthesized at Astellas Pharma Inc. (Tokyo, Japan) with an HPLC purity exceeding 97%. 1H NMR (CDCl3, 400 MHz) (ppm) = 1.31 (d, 6H, J = 6.8 Hz), 1.58− 1.80 (m, 4H), 1.90−2.04 (m, 2H), 2.16−2.84 (m, 12H), 3.18− 3.32 (m, 1H), 3.66−3.76 (m, 2H), 3.88 (s, 3H), 6.48−6.60 (m, 2H), 7.18−7.26 (m, 1H), 7.50−7.72 (m, 2H), 7.86−7.92 (dd, 1H, J = 1.2 Hz, J = 7.6 Hz), 8.06−8.16 (m, 1H), 8.28−8.48 (m, 1H), 8.48−8.62 (m, 1H), 9.28 (s, 1H). Differential Scanning Calorimetry Analysis. Differential scanning calorimetry (DSC) analysis was conducted using a TA Instruments Q-2000 calorimeter (TA Instruments, New Castle, DE, USA) under the following conditions: measurement temperature range, ambient temperature to ≥493 K; rate of temperature increase, 30 K/min; nitrogen flow rate, 50 mL/ min; and sample pan material, aluminum sealed pans. Solubility Measurement and Quality Evaluation. ASP3026 concentration in the supernatant and ASP3026 assay and impurities of crystal were analyzed using highB
DOI: 10.1021/acs.oprd.6b00068 Org. Process Res. Dev. XXXX, XXX, XXX−XXX
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then analyzed based on the Raman shift to determine the relative amounts of A03 and A04 present. In addition, given that DSC has been used in previous studies to quantify the weight percentages of A03 and A04, the solid was also analyzed using that method. Process Development for Scale-up. The scaled-down glass reactor of our pilot plant equipment was used for process development. 50% acetone−water (152 mL) was added to the scaled-down glass reactor, and the agitation rate was set to 500 rpm. The temperature in the vessel was heated to approximately 335 K using a thermostatic bath. Crude ASP3026 (25.4 g) was added to the solvent, and after 25 mg of A04 had been seeded, the slurry was agitated at a constant temperature of approximately 335 K for predetermined duration. 50% acetone−water (51 mL) was added after the slurry flowability deteriorated due to polymorph transformation of A02. After the precipitated solid was analyzed using DSC and the desired crystal form A04 was successfully obtained without contamination of other polymorphic forms, the slurry was cooled to 298 K at a constant rate of 5 K/h. The precipitated solid was then obtained by filtration and drying. A small amount of crystal was collected at several time points during polymorph transformation. The precipitated crystal was observed via scanning electron microscope (SEM; VE-8800; Keyence Corp., Osaka, Japan) and analyzed using DSC. The relative amounts of A02 and A04 were determined using the heat-of-fusion ratio of A02 and A04 by DSC analysis when the heat-of-fusion of A03 was not detected in the precipitated crystal. Polymorph transformation was monitored using a Raman Rxn2 785 (Kaiser Optical System, Inc.), and the change in crystal size was evaluated using FBRM (D600; MettlerToledo).
Figure 4. (a) Weight percentage of A04 (RA04) and Raman shift of approximately 833 cm−1. (b) Weight percentage of A04 (RA04) and Raman shift of approximately 1310 cm−1.
until the beginning of polymorph transformation. The induction time and the disappearance time of A02 were estimated based on changes in Raman peak intensity. No significant differences were observed in Raman spectra between A03 and A04. Given previous reports that the Raman shift can be used for polymorph quantification,13 Raman shift was used to determine the relative amounts of A03 and A04. Figure 4a and b show the relationship between the weight percentage of A04 (RA04) and Raman shifts of both approximately 833 and 1310 cm−1. Raman shifts of both approximately 833 and 1310 cm−1 were considered a good linear relationship between Raman shift and RA04. The average value with calibration curves in Figure 4a and b was used to determine the relative amounts of A03 and A04. Table 2 shows findings regarding the effects of solvent and temperature on polymorph transformation. A04 was deemed the most stable polymorph, based on a previous solubility study,5,6 and the relationship between A04 and A03 was monotropic. However, solubility between these two forms does not markedly differ. Extremely little solvent-mediated polymorph transformation of A03 to A04 occurred even under the high temperature condition (at 338 K for 8 h) in MEK.14 Controlling the nucleation of A03 and A04 for selective crystallization was therefore a high-priority issue. Further, the end point of the solvent-mediated polymorph transformation was considered to be the time after there was no A02 form in the slurry. Each polymorph was also analyzed through high-sensitivity analysis using the heat-of-fusion ratio of A03 and A04, which was determined in DSC analysis. DSC method was able to detect approximately 1% of contamination of the other polymorphic forms. The relative amounts of A03 and A04 on DSC-based calibration curve analysis were compared with amounts obtained using Raman spectroscopy. Quantification methods with DSC and Raman spectroscopy produced similar results of the relative amounts of A03 and A04. The results showed that approximately 10% or less of A03 was included after polymorph transformation at 323 K with calibration
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RESULTS AND DISCUSSION Polymorph Transformation Study of A02. The solvents listed in ICH Guideline Class 310 and organic solvent−water
Figure 3. Time dependence at normalized peak intensity (1240 cm−1) at 323 K.
mixtures were used to obtain A04. The selected solvents and the solvent property parameters are shown in Table 1. Figure 2 shows the Raman spectra of A02, A03, and A04. The prominent peak at approximately 1240 cm−1 enabled identification of A02. Polymorph transformation of A02 was analyzed with a peak intensity of 1240 cm−1. Figure 3 shows time dependence at a normalized peak intensity of 1240 cm−1 in MEK, acetone, and EtOH. The induction times in this study were defined as the time period from the addition of ASP3026 C
DOI: 10.1021/acs.oprd.6b00068 Org. Process Res. Dev. XXXX, XXX, XXX−XXX
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Table 2. Experimental Results under Various Conditions polymorph Raman temperature EtOH IPA acetone MEK MIBK AcOEt 50% acetone−water 50% EtOH−water a
323 298 323 298 323 298 323 298 323 298 323 298 323 298 323 298
K K K K K K K K K K K K K K K K
DSC
c
RA04
90% 6% 97%
A04 solubility
induction time
RA03
9.7 g/L 3.1 g/L 7.8 g/L 0.8 g/L 10.2 g/L 4.0 g/L 16.6 g/L 5.8 g/L 8.3 g/L 3.2 g/L 9.6 g/L 3.7 g/L 11.0 g/L 4.5 g/L 15.9 g/L 5.4 g/L
10.7 h 427.5 h 39.2 h > 768 h 5.8 h 66.4 h 1.4 h 39.6 h 8.4 h 83.0 h 2.7 h 159−216 h 15.1 h >330 h 9.2 h >567 h
10% 94% 3% N.A.a 4% 62% 1% 45% 2% 94% 5% 100% 5% N.A.a 10% N.A.a
c
96% 38% 99% 55% 98% 6% 95% 0% 95% 90%
RA03c b
N.D. 91.3% N.D.b N.A.a N.D.b 65.1% N.D.b 45.9% N.D.b 89.6% N.D.b 97.5% N.D.b N.A.a N.Db N.A.a
RA04c 100% 8.7% 100% 100% 34.9% 100% 54.1% 100% 10.4% 100% 2.5% 100% 100%
Not Analyzed (N.A.). bNot Detected (N.D.). cThe weight percentage of A03, A04 (RA03, RA04).
50% EtOH−water, EtOH, 50% acetone−water, and then longest with IPA. Induction time at 298 K was shortest when using MEK, followed by acetone, MIBK, AcOEt, and then EtOH. Of note, no solvent-mediated polymorph transformation of A02 was observed even after 300 h when using IPA, 50% acetone−water, or 50% EtOH−water. Taken together, these findings indicate that ketones and esters solvents tend to shorten the induction time, regardless of temperature. Given disparities in induction time between MEK and 50% EtOH-water despite markedly similar solubility, the relationship between induction time and solvent property parameters at 298 K was investigated in detail. Figure 6a describes the relationship between induction time and the solvent parameters of dipole moment, polarity/dipolarity (π) and dielectric constant at 298 K. Of note, the plots only used data after polymorph transformation had actually occurred. Induction time shortened with increasing dipole moment and π but tended to lengthen when water-containing organic solvents such as 50% acetone− water (not shown) were used. Other parameters were therefore assumed to influence induction time as well. Little correlation between induction time and the dielectric constant was noted. Figure 6b and c describes the relationship between induction time and the value of Σα (HBD) or Σβ (HBA) as well as Hansen solubility parameter (δ), including dispersion component (δd), polar component (δp), and hydrogen bonding component (δh). The value of Σα and δh were found to be wellcorrelated with induction time. Given that ASP3026 contains 2 HBDs and 11 HBAs in its structure,15 hydrogen bond-donating solvents were assumed to be easily coordinated in the vicinity of the strong hydrogen bond-accepting molecules. Nonsolvate crystals A03 and A04 would therefore need to desolvate before nucleation, increasing the activated energy of nucleation. Obtaining the desired polymorph A04 via solvent-mediated polymorph transformation of A02 required selecting those conditions which shortened the induction time. A04 was subsequently obtained at high temperature using highly polar non-hydrogen-bond-donating solvents, while A03 was obtained
Figure 5. Relationship between RA04 and induction time.
analysis using Raman spectroscopy. However, the heat-offusion of A03 was not actually detected by DSC analysis. Therefore, the limit of quantification using Raman spectroscopy was considered to be approximately 10% of A03 contamination. Regardless of the solvent species used, pure A04 was always obtained at 323 K, indicating that solvents had no effect on polymorphs produced at 323 K. Indeed, previous findings have suggested that solution conformation largely resembles the A04 polymorph at higher temperatures.14 A04 was therefore successfully obtained at 323 K. In contrast, a mixture of A03 and A04 was obtained at 298 K. It is thought that the solution conformation might resemble the mixture of A03 and A04 at 298 K. Furthermore, relative amounts of A03 and A04 at this temperature depended on the solvent used. Figure 5 shows the relationship between the weight percentage of A04 (RA04) at the end of polymorph transformation and induction time. As shown in the figure, induction time increased with decreasing RA04. Given the importance of induction time in obtaining A04, the effects of solvent species on induction time were carefully considered. Induction time significantly shortened as temperature increased from 298 to 323 K, and the value at 323 K was shortest when using MEK, followed by AcOEt, acetone, MIBK, D
DOI: 10.1021/acs.oprd.6b00068 Org. Process Res. Dev. XXXX, XXX, XXX−XXX
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Figure 7. Solubility in 50% acetone−water.
Figure 8. Process flow for first-scale up.
Table 4. Experimental Conditions
material reactor diameter impeller diameter impeller baffle manufacturing-scale crude ASP3026 agitation rate
Figure 6. (a) Relationship between induction time and dipole moment, π, and dielectric constant. (b) Relationship between induction time and the value of Σα or Σβ. (c) Relationship between induction time and δ, including each component δ value.
lab
pilot plant 200 L batch reactor
glass 75 mm 53 mm Pfaudler finger 25.4 g
glass lining 600 mm 420 mm Pfaudler finger 13.0 kg
500 rpm
125 rpm
The crude crystal A02 was purified after polymorph transformation, and three impurities detected at relative retention times of 0.18, 0.22, and 0.47 were effectively removed except for that of 2.17. The crude crystal A02 contained residue on ignition, such as sodium chloride, from preliminary experiments, but this residue proved difficult to remove via crystallization using organic solvents such as MEK and acetone. Subsequently, the residue on ignition of the product did not meet the acceptance criteria (0.2% or less) after polymorph
at low temperature using low-polarity or hydrogen-bonddonating solvents. Effect of Polymorph Transformation on Product Quality. Quality of ASP3026 before and after polymorph transformation of A02 in acetone, MEK, and 50% acetone− water is described in Table 3. Table 3. Quality and Yield
quality RRTa initial acetone MEK 50% acetone−water a
temperature
yield
ASP3026
0.18
0.22
0.47
2.17
polymorph
residue on ignitionb
323 K 323 K 323 K
82% 76% 88%
98.9% 99.5% 99.6% 99.4%
0.08% 0.04% 0.03% 0.01%
0.15% 0.03% 0.01% 0.02%
0.22% 0.03% 0.01% 0.02%
0.07% 0.05% 0.04% 0.07%
A02 A04 A04 A04
0.47% 0.56%
