MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
`Title: L-221869 (dipeptidyl-peptidase IV)
`Category: Endocrine/Metabolic
`Target Class: dipeptidyl-peptidase IV
`Compound #: 0726
`Disease: noninsulin-dependent diabetes mellitus Dosage Form/Potency: To Be Determined
`Cross Project Function:
`Reporting Area: Pharmaceutical Research & Development
`Project Team:
`Sub-Group: Pharmaceutical Chemistry Rahway
`Dept. : 854 Pharmaceutical Research
`Author(s): Shultz, Leigh
`Department Head: Michael Kaufman
`Key Words: Bulk and solution stability; HCl salt; p-toluenesulfonate salt; benzenesulfonate salt; tartrate salt; hydrolysis and de-
`amination; solubility; pKa; stoichiometry (tartaric acid salt); 1:1 salt; buffer; hemihydrate
`
`Summary
`Bulk and solution stability studies (1, 2, and 4 week) have been completed for the HCl, p-toluenesulfonate,
`bezenesulfonate, and L-tartrate salts of L-221869. Limited solubility data is also available for these salts, with the
`exception of the HCl salt. The pKa of L-221869 has been measured by titration as 7.98. HPLC, VTI, TGA, and
`DSC data indicate that the L-tartrate salt of L-221869 is a 1:1 salt and exists as a hemihydrate.
`
`1.
`
`Bulk and solution stability of L-221869 HCl salt [NB: (60659:101, 104, 107, 122, 136)]
`
`Bulk stability of the HCl salt was ascertained by HPLC analysis of samples stored at 40 °C/75% RH and at 80 °C/amb RH for 1, 2,
`and 4 weeks. The stability data are shown in the table below and are reported in area % relative to samples stored at 20 °C.
`
`Table 1. Bulk thermal stability of L-221869 HCl salt
`Conditions
`Rel Area % L-221869
`1 wk 2 wk 4 wk
`nd
`97.2
`98.6
`40 °C/75% RH
`nd
`99.5
`100.8
`80 °C/amb RH
`nd = no data due to LC error
`
`No data was collected during analysis of the 1-week samples due to an LC error. The data at 40 °C/75% RH suggest that some
`hydrolysis of the parent is resulting in loss of L-221869. This is expected based on the relatively high hygroscopicity of this salt (data
`from Y. Wang, Analytical Research). The stability of the HCl salt of L-221869 in solution was evaluated by HPLC analysis of
`samples stored at 40 and 80 °C in aqueous solutions of varying pH. The solution stability data are shown in the table below. Data are
`reported in area % relative to samples stored at 20 °C.
`
`Conditions
`
`water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`Table 2. Solution thermal stability of L-221869 HCl salt
`Rel Area % L-221869, 40 °C
`Rel Area % L-221869, 80 °C
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`88.0
`82.5
`64.9
`nd
`0.0
`0.3
`100.4
`99.7
`100.0
`nd
`97.6
`96.0
`99.7
`100.1
`99.8
`nd
`97.0
`93.7
`103.2
`100.1
`99.0
`nd
`8.2
`0.6
`92.3
`82.4
`59.5
`nd
`0.0
`0.0
`80.1
`60.0
`33.5
`nd
`0.0
`0.0
`
`The HCl salt is most stable in solution at pH 2, though some hydrolysis is still observed at 80 °C at this pH. The salt is very unstable
`above pH 6.
`
`2.
`
`Bulk and solution stability of L-221869 p-toluenesulfonate salt [NB: (60659:101, 104, 107, 122, 135)]
`
`The stability of bulk p-toluenesulfonate salt was evaluated by HPLC analysis of samples stored at 40 °C/75% RH and at 80 °C/amb
`RH for 1, 2, and 4 weeks. Data for the salt are shown the table below and are reported in area % relative to samples stored at 20 °C.
`
`Table 3. Bulk thermal stability of L-221869 p-toluenesulfonate
`
`Merck Exhibit 2151, Page 1
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 2 of 12
`
`Conditions
`
`Rel Area % L-221869
`1 wk 2 wk 4 wk
`nd
`98.5
`100.1
`40 °C/75% RH
`nd
`99.9
`99.8
`80 °C/amb RH
`nd = no data due to LC error
`
`
`
`An LC error resulted in no data being collected during analysis of the one-week samples. Nonetheless, the two- and four-week
`samples indicate that the p-TSA salt is stable toward hydrolysis and de-amination over 4 weeks. Solution stability was ascertained by
`HPLC analysis of samples stored at 40 and 80 °C in aqueous buffers of varying pH. The data are shown in Table 4 below and are
`reported in area % relative to samples stored at 20 °C.
`
`Conditions
`
`water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`Table 4. Solution thermal stability of L-221869 p-toluenesulfonate
`Rel Area % L-221869, 40 °C
`Rel Area % L-221869, 80 °C
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`87.4
`75.3
`56.1
`0.0
`0.0
`0.0
`100.1
`100.3
`100.4
`99.5
`97.3
`94.7
`100.1
`96.5
`100.0
`101.7
`95.4
`93.3
`102.3
`96.8
`98.6
`35.9
`7.8
`0.5
`89.0
`73.4
`54.0
`0.0
`0.0
`0.0
`76.0
`53.4
`28.4
`0.0
`0.0
`0.0
`
`The salt is most stable at pH 2 and pH 4, though some hydrolysis is observed at 80 °C under each of these conditions. The salt is
`unstable in water and in buffers above pH 6.
`
`3.
`
`Bulk and solution stability of L-221869 benzenesulfonate salt [NB: (60659:106, 114, 119, 124-125, 137)]
`
`The bulk stability data for the benzenesulfonate salt of L-221869 are shown in the table below. Data were obtained by HPLC analysis
`of samples stored at 40 °C/75% RH and 80 °C/amb RH for 1, 2, and 4 weeks. Data are reported in area % relative to samples stored
`at 20 °C.
`
`Table 5. Bulk thermal stability of L-221869 benzenesulfonate salt
`Conditions
`Rel Area % L-221869
`1 wk 2 wk 4 wk
`100.5
`100.1
`97.3
`100.0
`98.5
`99.6
`
`40 °C/75% RH
`80 °C/amb RH
`
`Some loss of parent is observed over 4 weeks at 40 °C/75% RH, but no degradates appear in the HPLC trace. The bulk appears to be
`stable toward de-amination over 4 weeks at 80 °C. The stability of the benzenesulfonate salt in solution was evaluated by HPLC
`analysis of samples stored at 40 and 80 °C in a variety of aqueous buffer solutions (20 mM). The solution stability data are shown in
`the table below and are reported in area % relative to samples stored at 20 °C.
`
`Conditions
`
`water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`Table 6. Solution thermal stability of L-221869 benzenesulfonate salt
`Rel Area % L-221869, 40 °C
`Rel Area % L-221869, 80 °C
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`87.5
`73.0
`52.1
`0.0
`0.0
`0.0
`100.2
`97.0
`99.2
`98.4
`94.7
`92.8
`99.9
`97.9
`99.6
`98.5
`95.5
`94.6
`100.1
`96.5
`97.0
`33.6
`9.3
`0.6
`88.0
`74.0
`55.2
`0.0
`0.0
`0.0
`73.2
`54.0
`29.5
`0.0
`0.0
`0.4
`
`The benzenesulfonate salt is unstable in unbuffered water at both 40 and 80 °C. This is most likely a pH effect, as the native pH of
`the salt in water is greater than 6. The salt is most stable toward hydrolysis between pH 2 and 4. No de-amination is observed at pH
`2.
`
`Merck Exhibit 2151, Page 2
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 3 of 12
`
`4.
`
`Bulk and solution stability of L-221869 L-tartrate salt [NB: (60659:106, 114, 119, 124-125, 138)]
`
`The solid-state thermal stability of the tartrate salt of L-221869 was evaluated by HPLC analysis of samples stored at 40 °C/75% RH
`and 80 °C for 1, 2, and 4 weeks. The bulk stability data are shown in the table below and are reported in area % relative to samples
`stored at 20 °C.
`
`Table 7. Bulk thermal stability of L-221869 tartrate salt
`Conditions
`Rel Area % L-221869
`1 wk 2 wk 4 wk
`102.7
`99.6
`99.5
`101.9
`99.0
`99.4
`
`40 °C/75% RH
`80 °C/amb RH
`
`Minimal loss of parent is observed over 4 weeks; the loss is probably not statistically significant, and no degradates are observed by
`HPLC. Solution stability was measured by HPLC analysis of samples stored at 40 and 80 °C in aqueous buffers of varying pH for 1,
`2, and 4 weeks. The data are shown in Table 8 below and are reported in area % relative to samples stored at 20 °C.
`
`Conditions
`
`water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`Table 8. Solution thermal stability of L-221869 tartrate salt
`Rel Area % L-221869, 40 °C
`Rel Area % L-221869, 80 °C
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`99.5
`92.5
`87.5
`1.6
`0.0
`0.0
`99.7
`99.0
`99.6
`98.9
`97.6
`94.8
`95.9
`94.4
`100.0
`95.0
`92.6
`90.8
`99.8
`98.7
`98.9
`37.1
`11.6
`1.5
`92.2
`80.3
`63.8
`0.0
`0.0
`0.0
`83.9
`60.1
`34.7
`0.0
`0.0
`0.5
`
`The tartrate salt is most stable between pH 2 and 4, similar to other crystalline salts of L-221869. Although the stability of the salt in
`water at 80 °C is poor, the stability of the salt at 40 °C in water shows a marked improvement over the other salts of this compound.
`This is likely a pH effect; the tartaric acid in the salt buffers the water solutions and affords a pH between 3 and 4, where the drug is
`most stable. Table 9 below compares the degradation (both hydrolysis and de-amination) of L-221869 in the benzenesulfonate and
`tartrate salt forms at 0.1 mg/mL salt in water at 40 °C.
`
`Table 9. Comparison of degradation in salts of L-221869
`Rel Area %
`Rel Area %
`Hydrolysis
`De-amination
`1wk 2wk 4wk
`1wk 2wk 4wk
`8.9
`19.3
`46.6
`3.3
`6.4
`22.3
`1.9
`5.0
`9.5
`1.0
`2.6
`4.1
`
`Salt of L-221869
`
`Benzenesulfonate
`L-Tartrate
`
`The data clearly indicate that the tartrate salt is more stable in unbuffered water than the benzenesulfonate salt.
`
`5.
`
`Solubility of L-221869 p-toluenesulfonate salt [NB: (60659:102-103, 139)]
`
`The solubility of the p-toluenesulfonate salt of L-221869 was investigated in water, saline, 0.01 N HCl, and buffers from pH 4 to pH
`10. The HPLC was calibrated using standards of the p-toluenesulfonate salt in water, and the calibration plot is shown below.
`
`Merck Exhibit 2151, Page 3
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 4 of 12
`
`L-221869 pTSA Calibration
`
`parent
`
`pTSA salt
`
`pTSA counterion
`
`R2 = 0.9992
`
`R2 = 0.9992
`
`R2 = 1
`
`8000000
`7000000
`6000000
`5000000
`4000000
`3000000
`2000000
`1000000
`0
`
`area count
`
`0
`
`0.05
`
`0.15
`0.1
`Conc (mg/mL)
`
`0.2
`
`0.25
`
`The calibration data were used to determine the solubility of the p-toluenesulfonate salt in a variety of solvents. The solubility data
`are shown in Table 10 below.
`
`Table 10. Solubility of L-221869 p-toluenesulfonate salt
`Solvent
`Sol. Salt
`Sol L-221869
`pHinitial
`(mg/mL)
`(mg/mL)
`15.05
`10.43
`12.44
`8.62
`11.55
`8.01
`15.02
`10.41
`13.35
`9.25
`13.51
`9.36
`10.58
`7.33
`
`water
`saline
`0.01 N HCl
`20 mM sodium acetate
`20 mM sodium phosphate
`20 mM sodium phosphate
`20 mM sodium carbonate
`
`6.25
`5.90
`2.00
`4.02
`6.04
`7.97
`9.95
`
`pHfinal
`
`6.38
`6.20
`2.00
`3.95
`5.78
`7.27
`8.19
`
`Some of the samples (pH 2, 4, 6, 8, and 10) contained little to no solid after equilibration, so the solubility of the p-toluenesulfonate in
`these media may be higher. The solubilities in water and saline can be considered as equilibrium data. The final pHs of the solubility
`samples indicate that the salt does not dissociate to a high degree in these solvents.
`
`6.
`
`Solubility of L-221869 benzenesulfonate salt and L-221869 L-tartrate salt [NB: (60659:115-116, 139)]
`
`The solubilities of the benzenesulfonic acid and tartaric acid salts were also invesitgated in water and 0.01 N HCl. The data are shown
`in the table below along with the data for the free base (J. Remenar) and the p-toluenesulfonate for comparison.
`
`Table 11. Comparison of solubility data for crystalline salts and free base of L-221869
`Salt
`Solvent
`Sol. Salt
`Sol. L-221869
`pHinitial
`pHfinal
`(mg/mL)
`(mg/mL)
`n/a
`2.2
`15.1
`10.4
`>20.0
`>14.2
`>19.5
`>14.1
`n/a
`>20
`>11.6
`>8.0
`>10.0
`>7.1
`>10.0
`>7.2
`
`Free Base
`p-Toluenesulfonic acid
`Benzenesulfonic acid
`L-Tartaric acid
`Free Base
`p-Toluenesulfonic acid
`Benzenesulfonic acid
`L-Tartaric acid
`
`water
`water
`water
`water
`0.01 N HCl
`0.01 N HCl
`0.01 N HCl
`0.01 N HCl
`
`6.25
`5.85
`5.85
`
`2.00
`2.17
`2.17
`
`6.38
`6.17
`3.62
`
`2.00
`2.20
`3.02
`
`The benzenesulfonate and tartrate salts are more soluble in water than the p-toluenesulfonate salt. The data for the benzenesulfonate
`and tartrate cannot be considered equilibrium values, as the entire solid sample dissolved in the course of the equilibration. The final
`pH of the tartrate salt solution is of note, as this is in the most stable pH range for L-221869.
`
`Merck Exhibit 2151, Page 4
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 5 of 12
`
`7.
`
`pKa determination for L-221869 free base [NB: (60659:131-133)]
`The pKa of L-221869 was determined by titration of a sample of the crystalline free base (39.22 mg) in water (50.0 mL) with 0.10 N
`HCl. The pH of the solution was measured using a glass electrode and pH meter after the addition of each of 10 aliquots of HCl.
`Data analysis produced a pKa value of 7.98 (scatter 0.13).
`Stoichiometry of L-221869 L-tartrate salt [NB: (60659:116, 126, 128-130)]
`8.
`
`HPLC data from two different concentration of the tartaric acid salt were analyzed against known standards of the p-toluenesulfonate
`salt (see calibration plot above) to determine the stoichiometry of the tartaric acid salt. L-221869 forms a hemifumarate salt and might
`also form 2:1 salts with other dicarboxylic acids such as L-tartaric acid. The concentrations of L-221869 parent in the two samples
`were determined from the calibration and were compared to the theoretical L-221869 concentrations for both a 1:1 salt and a 2:1 salt
`(hemitartrate).
`
`Table 12. Stoichiometry of the L-tartrate salt of L-221869
`[salt]
`[869]
`Theo [869], 1:1
`Theo [869], 2:1
`(mg/mL)
`(mg/mL)
`salt (mg/mL)
`salt (mg/mL)
`0.1
`0.065
`0.072
`0.084
`0.05
`0.033
`0.036
`0.042
`
`Sample
`
`A
`B
`
`The data suggest that the tartaric acid salt of L-221869 is a 1:1 salt. This conclusion is supported by solution 1H NMR data (M.
`Palucki, Process Research). The native pH of a concentrated solution of L-221869 tartrate in water (see solubility data above) is 3.62,
`suggesting the presence of a free carboxylic acid group and consistent with a 1:1 salt. The tartaric acid in this salt is half protonated
`and would be expected to buffer an aqueous solution of the salt; this is evident in the raising of the pH value when the tartrate salt of L-
`221869 is added to 0.01 N HCl (see solubility data above).
`
`Reports from Analytical Research suggested that the tartrate salt of L-221869 is slightly hygroscopic. TG results (Y. Wang) indicated
`1.6% weight loss, and moisture content was estimated at 2% by Karl-Fischer titration of the salt. Dynamic vapor sorption analysis (Y.
`Wang) of the salt from 5-95% RH at 25 °C indicated that the salt gained 1.0 wt % water by 10% RH and gained a total of 1.8 wt %
`water by 95% RH.
`
`Given these results, the hygroscopicity of the tartrate salt was measured at 40 °C, producing the data shown in the moisture sorption
`isotherms below:
`
`Adsorption/Desorption Isotherm
`
`Adsorption
`
`Desorption
`
`Adsorption/Desorption Isotherm
`
`Adsorption
`
`Desorption
`
`0
`
`20
`
`40
`
`60
`
`80
`
`100
`
`%RH
`
`0.8000
`
`0.7000
`
`0.6000
`
`0.5000
`
`0.4000
`
`0.3000
`
`0.2000
`
`0.1000
`
`0.0000
`
`H2O/sample (moles)
`
`0
`
`20
`
`40
`
`60
`
`80
`
`100
`
`%RH
`
`2.500
`
`2.000
`
`1.500
`
`1.000
`
`0.500
`
`0.000
`
`Weight (% change)
`
`These results are nearly identical to the results obtained at 25 °C in Analytical Research. The presence of a hydrated form was
`considered, and the hemihydrate was calculated to be 1.64 wt % water. The VTI data at both 25 and 40 °C suggest that the salt exists
`as a hemihydrate under ambient conditions. The material from the VTI run at 40 °C was analyzed by DSC and TGA. The
`thermograms are shown below.
`
`Merck Exhibit 2151, Page 5
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 6 of 12
`
`Sample: 869Tartrate_afterVTI40C
`Size: 3.5360 mg
`Method: standard method
`1.875%
`(0.06631mg)
`
`100
`
`TGA
`
`File: C:...\TGA\L221869_tar_vti40
`Operator: LS
`Run Date: 8-Jan-02 09:54
`
`1.997%
`(0.07061mg)
`
`90
`
`80
`
`Weight (%)
`
`Sample: L-221869_tartrate_VTI_40C
`Size: 1.1800 mg
`Method: standard
`0
`
`DSC
`
`File: C:...\DSC\869tar_vti40
`Operator: LS
`Run Date: 8-Jan-02 10:05
`
`64.67°C
`33.02J/g
`
`129.85°C
`
`201.68°C
`92.66J/g
`
`248.60°C
`211.63°C
`240.51°C
`208.75°C
`37.20J/g
`27.38J/g
`
`-2
`
`-4
`
`-6
`
`Heat Flow (W/g)
`
`-8
`20
`
`Exo Up
`
`203.50°C
`
`70
`
`170
`120
`Temperature (°C)
`
`220
`
`270
`
`Universal V2.3C TA Instruments
`
`70
`20
`
`70
`
`170
`120
`Temperature (°C)
`
`220
`
`270
`
`Universal V2.3C TA Instruments
`
`The TGA data indicate that the hemihydrate loses water steadily until 100 °C, when it experiences sudden weight loss. The total
`weight loss is slightly higher than expected for a hemihydrate (1.64%). DSC (closed pan) shows a shallow endotherm before the melt,
`possibly corresponding to loss of water from the crystal lattice. The material remaining is still crystalline, however, and a crystalline
`endotherm is seen for melting of the anhydrous material at 203.5 °C. When the ½ equivalent of water is figured into the molecular
`formula, the conversion factor for the L-tartrate hemihydrate salt becomes free base = 0.710(L-tartrate hemihydrate salt). The
`theoretical values for the 1:1 salt in Table 12 above then become 0.071 mg/mL parent for an 0.1 mg/mL solution of the tartrate salt
`and remain 0.036 mg/mL parent for an 0.05 mg/mL solution of the tartrate salt. Although this still does not explain why the
`experimental concentrations are lower than expected (and this is likely due to inaccuracies in the original concentration of salt), the
`summation of all of the above data does suggest that the L-tartrate salt of L-221869 exists as a reversibly-formed hemihydrate under
`ambient conditions.
`
`Title: Dipeptidyl-peptidase IV
`Category: Endocrine/Metabolic
`Target Class: dipeptidyl-peptidase IV
`Compound #:
`Disease: noninsulin-dependent diabetes mellitus Dosage Form/Potency: To Be Determined
`Cross Project Function:
`Reporting Area: Pharmaceutical Research & Development
`Project Team:
`Sub-Group: Pharmaceutical Chemistry Rahway
`Dept.: 854 Pharmaceutical Research
`Author(s): Shultz, Leigh
`Department Head: Michael Kaufman
`Key Words: L-224715-000T001; XRPD; crystalline; needle-like crystals; TG analysis; DSC; inclusion solvate; non-hygroscopic;
`equilibrium solubility; bulk stability; de-amination; solution stability; amide hydrolysis; photostability
`
`Summary
`The DP-IV antagonist L-224715 was received as the free base (-000T001), which was determined to be crystalline by X-ray powder
`diffraction. Microscopy shows the white powder to be birefringent, consisting of needles between 50-100 mm in length with an as
`pect ratio ca. 10:1. DSC and TGA results indicate that the free base is a single polymorph, melting at 118 °C with concomitant
`release of 0.4 wt % volatiles. L-224715-000T001 is non-hygroscopic, gaining 0.125 wt % water between 5 and 95% RH. The
`equilibrium solubility of the free base in water is 5.9 mg/mL with a native pH of 9.4.
`
`The crystalline free base degrades by thermal de-amination in the bulk after 2 weeks at 80 °C. In solution, hydrolysis of the amide
`bond is observed at all pHs and occurs under relatively mild conditions (25 °C) at high pH. Solutions of L-224715-000T also
`undergo de-amination at elevated temperature at high pH; they are most stable toward both degradation pathways at pH 2.
`Additionally, both bulk L-224715-000T and solutions of L-224715-000T have been found to be photostable and need not be protected
`from laboratory light.
`
`1.
`
`Physical properties of L-224715-000T001 [NB: (60659:109-110, 112-113, 118-119, 121, 141)]
`
`Merck Exhibit 2151, Page 6
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 7 of 12
`
`The XRPD pattern of L-224715-000T001 (Figure 1) is indicative of a crystalline material, with numerous sharp peaks between 2 and
`40° 2-theta.
`
`counts
`
`8000
`
`7000
`
`6000
`
`5000
`
`4000
`
`3000
`
`2000
`
`1000
`
`0
`
`5
`
`10
`
`15
`
`Figure 1. XRPD pattern for L-224715-000T001 (free base)
`
`20
`
`25
`
`30
`
`35
`
`40
`°2Theta
`
`The material appeared birefringent under plane polarized light, with needle-like crystals approximately 50-100 m in length and 5-10
`m in width (Figure 2).
`
`Figure 2. Microscope image of L-224715-000T001 (200X magnification)
`
`TG analysis (Figure 3) of L-224715-000T001 indicates that 0.39 wt % is lost by 150 °C; Medicinal Chemistry confirmed that the
`batch provided contained 0.39 wt % 2-propanol (determined by 1H NMR spectroscopy). DSC (Figure 4) data indicate the presence of
`a single polymorph, which melts at 118.01 °C (102.7 J/g). Comparison of the DSC and TGA results shows that loss of volatiles
`occurs simultaneously with melting, suggesting an inclusion solvate.
`
`Merck Exhibit 2151, Page 7
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 8 of 12
`
`Sample: L224715_freebase_dsc
`Size: 1.3200 mg
`Method: standard
`1
`
`116.80°C
`102.7J/g
`
`DSC
`
`File: C:...\L224715_fb_DSC.000
`Operator: LS
`Run Date: 4-Dec-01 15:31
`223.37°C
`107.0J/g
`
`255.39°C
`
`118.01°C
`
`70
`
`170
`120
`Temperature (°C)
`
`220
`
`270
`Universal V2.3C TA Instruments
`
`-1
`
`-3
`
`-5
`
`-7
`
`Heat Flow (W/g)
`
`-9
`20
`Exo Up
`
`Sample: L224715_fb_tga
`Size: 3.6000 mg
`Method: standard method
`110
`
`TGA
`
`File: C:...\TGA\L224715_fb_tga
`Operator: LS
`Run Date: 4-Dec-01 14:45
`
`0.3858% Loss before 150 deg C
`(0.01389mg)
`
`50
`
`100
`
`200
`150
`Temperature (°C)
`
`250
`
`300
`Universal V2.3C TA Instruments
`
`100
`
`90
`
`80
`
`70
`
`60
`
`0
`
`Weight (%)
`
`Figure 3. TGA of L-224715-000T001 (10 °C/min)
`
`Figure 4. DSC of L-224715-000T001 (10 °C/min)
`
`Dynamic vapor sorption analysis of the material (Figure 5) at 25 °C between 5 and 95% RH indicates that the crystalline free base is
`non-hygroscopic, gaining 0.125 wt % water over the entire relative humidity range.
`
`Adsorption/Desorption Isotherm
`
`Adsorption
`
`Desorption
`
`0.140
`0.120
`0.100
`0.080
`0.060
`0.040
`0.020
`0.000
`
`Weight (% change)
`
`0
`
`20
`
`40
`
`60
`
`80
`
`100
`
`%RH
`
`Figure 5. Hygroscopicity of L-224715-000T001 at 25 °C
`
`The equilibrium solubility of L-224715-000T001 at ambient temperature was determined in water and 0.9% aqueous NaCl. The
`results appear in Table 1 below. Samples were allowed to equilibrate for 18 hours prior to analysis by HPLC.
`
`Table 1. Equilibrium solubility of L-224715-000T001
`Solvent
`Solubility (mg/mL)a
`pHinitial
`pHfinal
`Water
`6.47
`9.37
`5.9
`0.9% NaCl
`5.80
`9.31
`5.7
`a sample contained between 0.2 and 0.5 area % of the hydrolysis degradate
`
`2.
`
`Solid-state and solution thermal stability of L-224715-000T001 [NB: (60659:110-111, 117, 123, 126-127, 140)]
`
`Merck Exhibit 2151, Page 8
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 9 of 12
`
`The bulk stability of L-224715-000T001 was determined at 20 °C, 5 °C, 25 °C/60% RH, 40 °C, 40 °C/75% RH, 60 °C, and 80 °C.
`The percent initial drug content was determined after 1, 2, and 4 weeks and is calculated as area percent data relative to the samples
`stored at 20 °C. Samples at 25 °C/60% RH and 40 °C/75% RH were stored open to the atmosphere. Other samples were stored in
`closed vials. The data are shown in Table 2 below.
`
`Table 2. Bulk thermal stability of L-224715-000T001
`Conditions
`Rel Area % L-224715
`1 wk 2 wk 4 wk
`100.3
`99.4
`102.0
`101.7
`101.7
`102.7
`102.0
`101.3
`101.3
`99.3
`100.9
`101.9
`100.0
`100.9
`102.8
`100.2
`100.5
`99.1
`
`5 °C/amb RH
`25 °C/60% RH
`40 °C/amb RH
`40 °C/75% RH
`60 °C/amb RH
`80 °C/amb RH
`
`L-224715-000T001 is stable in the solid state for 4 weeks at 60 °C. The major degradates coelute at RRT 1.3 and are attributed to de-
`amination of the parent (not yet confirmed). The de-amination degradates appear only in the samples stored at 80 °C/amb RH for 2
`weeks (0.53 absolute area %) and 4 weeks (1.31 absolute area %).
`
`The stability of L-224715-000T in solution (0.1 mg/mL) was determined at 5 °C, 25 °C, 40 °C, and 80 °C. The relative amount of
`parent remaining was determined at 1, 2, and 4 weeks and is calculated in HPLC area percent relative to samples stored at 20 °C.
`The data are shown in Table 3.
`
`Table 3. Solution-phase thermal stability of L-224715-000T001
`5 °C
`25 °C
`40 °C
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`1 wk 2 wk 4 wk
`99.9
`98.2
`99.3
`98.0
`91.7
`88.0
`88.4
`71.5
`54.9
`99.3
`99.6
`99.4
`99.4
`100.0
`99.6
`99.5
`100.0
`99.8
`114.3
`100.0
`98.9
`97.0
`100.2
`99.1
`114.3
`100.3
`99.7
`98.8
`99.9
`100.1
`98.8
`100.3
`100.1
`98.5
`99.1
`97.5
`99.1
`100.1
`99.6
`97.1
`95.4
`90.8
`88.2
`77.3
`58.2
`98.8
`98.7
`98.2
`96.2
`89.4
`79.4
`83.8
`62.0
`36.7
`
`80 °C
`1 wk 2 wk 4 wk
`1.1
`0.4
`0.0
`98.4
`97.7
`95.1
`94.9
`95.7
`87.9
`20.3
`4.4
`0.3
`0.5
`0.5
`0.5
`2.4
`0.5
`0.5
`
`Condition
`water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`The major degradates in solution elute at RRT 0.17, 0.91, and 1.3. The degradates at 0.17 and 0.91 have been identified as the
`products of amide hydrolysis by comparison with samples provided by Medicinal Chemistry. The degradates at RRT 1.3 are
`tentatively assigned as the de-amination products. Table 4 below compares area % degradates (absolute rather than relative) for
`L-224715 samples stressed at 80 °C for 1, 2, and 4 weeks.
`
`Table 4. HPLC area % degradates for L-224715-000T samples stressed at 80 °C
`RRT 0.17 (hydrolysis)
`RRT 0.91 (hydrolysis)
`RRT 1.3 (de-amination)
`1 wk 2wk 4wk
`1 wk 2wk 4wk
`1 wk 2wk 4wk
`6.80
`8.95
`4.22
`18.70
`19.96
`22.38
`72.91
`68.12
`68.30
`0.45
`0.76
`0.60
`0.68
`1.52
`2.97
`0
`0
`0
`0.34
`0.51
`0.83
`0.43
`1.00
`1.93
`2.33
`2.69
`5.99
`6.14
`7.61
`8.72
`17.17
`20.89
`22.65
`44.26
`65.21
`66.26
`13.68
`14.94
`15.19
`23.15
`23.73
`23.32
`60.29
`58.45
`58.73
`18.43
`17.83
`17.91
`34.98
`34.25
`33.63
`43.80
`43.07
`43.95
`
`Conditions
`Water
`pH 2
`pH 4
`pH 6
`pH 8
`pH 10
`
`L-224715 is most stable at pH 2, where no de-amination is observed. Less than 5% parent remains at 80 °C above pH 6 after 2 weeks;
`almost no parent (0.3 area %) remains after 4 weeks at 80 °C.
`
`3.
`
`Bulk and solution photostability of L-224715-000T001 [NB: (60659:116-117, 130, 132, 140)]
`
`Merck Exhibit 2151, Page 9
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 10 of 12
`
`Bulk photostability of L-224715-000T was determined by irradation of a sample of L-224715-000T001 with fluorescent light for 17
`hours in a Rayonet irradiator. An identical sample was wrapped in aluminum foil and placed in the Rayonet to provide a dark
`reference. Both samples were dissolved and assayed by HPLC after irradiation; the light-exposed bulk sample had a relative area %
`parent of 100.5 with respect to the dark sample, indicating that L-224715-000T is stable to laboratory light.
`
`Solutions of L-224715-000T in water, 0.01 N HCl, and buffers ranging in pH from 4 to 10 were exposed to fluorescent light in a
`Rayonet irradiator for 17 hours. Identical samples were wrapped with aluminum foil and placed in the Rayonet to provide dark
`references. The photostability data are listed in Table 5 and are reported relative to the dark samples.
`
`Table 5. Solution photostability of L-224715-000T001
`pH
`Relative Area %
`L-224715
`101.2
`100.6
`100.0
`99.9
`99.9
`99.3
`
`Water
`2
`4
`6
`8
`10
`
`Photostability samples at high pH (8 and 10) show some hydrolysis and de-amination, but the dark samples do not differ significantly
`from the light-exposed samples in this regard. Solutions of L-224715-000T001 do not need to be protected from laboratory light
`exposure.
`
`4.
`
`Modes of degradation for L-224715 [NB: (60659:112)]
`
`The two major pathways for degradation of L-224715 are shown in the scheme below. The first pathway is hydrolysis of the amide
`bond, producing a free amine and a carboxylate species. The second pathway is thermally induced de-amination. The carboxylate
`species produced by hydrolysis of the amide likely undergoes subsequent de-amination, preventing reformation of the parent. These
`degradation pathways have not yet been confirmed by LC-MS analysis.
`
`F
`
`F
`
`F
`
`F
`
`F
`
`F
`
`NH2
`
`O
`
`F
`
`acid
`or
`base
`
`N
`
`N
`
`N
`
`N
`
`CF3
`
`F
`
`O
`
`N
`
`N
`
`N
`
`N
`
`F
`
`F
`
`F
`
`F
`
`CF3
`proposed de-amination degradates
`
`NH2
`
`O
`
`HN
`
`O
`
`hydrolysis degradates
`
`N
`
`N
`
`N
`
`CF3
`
`O
`
`N
`
`N
`
`N
`
`N
`
`CF3
`
`Merck Exhibit 2151, Page 10
`Mylan Pharmaceuticals Inc. v. Merck Sharp & Dohme Corp.
`IPR2020-00040
`
`

`

` MERCK RESEARCH LABORATORIES PROGRESS REPORT
` JANUARY 2002
`
` Page 11 of 12
`
`Title: Peroxisome Proliferator-Activated Receptor (PPAR)
`Target Class: peroxisome proliferator-activated receptor
`Dosage Form/Potency: To Be Determined
`
`Category: Endocrine/Metabolic
`Compound #:
`Disease: diabetes
`Cross Project Function:
`Project Team:
`Dept.: 854 Pharmaceutical Research
`Department Head: Michael Kaufman
`Key Words: L-383548-001X001; amorphous; HPLC method development; degradation
`Summary
`Initial physical characterization of the PPAR compound L-383548-001X001 indicates that the sodium salt is
`amorphous. An HPLC method has been developed and was used to assay samples of the compound stressed in acid,
`base, and peroxide. Very few degradates were observed in the stressed samples.
`
`Reporting Area: Pharmaceutical Research & Development
`Sub-Group: Pharmaceutical Chemistry Rahway
`Author(s): Shultz, Leigh
`
`1.
`
`Initial physical characterization of L-383548-001X001 (sodium salt) [NB: (60659:127)]
`
`A microscope image (200X magnification) was obtained of the sodium salt of L-383548-001X001.
`
`The salt is amorphous, showing no defined morphology or birefringence. The average particle size is between 100 200 m.
`
`2.
`
`HPLC method development for L-383548 [NB: (60659:128)]
`
`A stock solution of L-383548 was made by dissolving a sample of L-383548-001X001 (1.02 mg) in 1.00 mL of water. Aliquots of
`this stock solution were added