Solid-State NMR Utility in API and
Formulation Process Development
Robert Wenslow
VP Business Development
Crystal Pharmatech
www.crystalpharmatech.com
Areas of Application
Analytical
Organic Process
Engineering
Produce Stable,
Single Phase Bulk
Milling Compaction
Issues
Biopharmaceutics
Phys/Chem
Stability
Spec.
Justification
Bulk API Characterization
In Formulation Samples
Solvent
Stystem
Granulation
Processing
Conditions
In vivo
Excipient Tableting
performance Interactions
2
Challenging Pharmaceutical Issues
 Salt Disproportionation
 Polymorphs
 Solvates and Hydrates
 Amorphous dispersions
 Motivation is regulation
3
Solid-State NMR
Molecular Tumbling
Orientation leads to CS difference
Rigid Solid
http://www.dur.ac.uk/resources/SSNMR/Training_course_PH.pdf
4
Cross-Polarization (CP/MAS)
(90)
Contact Time
Decouple
1H
Detect
13C
D µ 1/r6
13C
Signal Buildup through
dipole coupling (D)
Signal Intensity
1H
Contact Time
J. Chem. Phys. 1973, 59, 569
5
Structure: Disproportionantion
K-salt disproportionates in water to the free acid
19F
NMR was used to determine the kinetics
Fast experiments, quantitative information
Can also probe in formulation
% Disproportionated
100
80
60
40
20
**
0
0
10
20
30
Time (Hrs)
40
50
6
Structure: Salt Formation
Lower decoupling obscures N’s connected to H
Disappearance of 2 peak predicted
Salt forms at 3 Nitrogen
Contact time can also be used to discriminate
4
Useful information but long measuring times
3
7
Polymorph Quantitation
19F
19F
NMR spectra of I and II
Form II
Form I
relaxation curves for I and II
1.2
Form I
Form II
0.8
0.4
0
-95
-100
-105
-110
-115
-120
0
-125
10
20
30
40
50
-0.4
-0.8
At 8.5 seconds FII shows zero signal
19F
relaxometry can be used
8
Solvate Identification
* Peaks from EtOH
CP discriminates against the more mobile regions
Form II DP/MAS
DP discriminates against the more rigid regions
Spectral editing combination is powerful to study solvates
Form II CP/MAS
Split –CH3 indicates multiple environments
Straight forward measurements
High information content
9
API in Drug Product
L454 Freebase
19F
SSNMR was used, measurements done at 5 oC
Formulation: API + PEG 600
At 40 mgs/mL API completely dissolved
At 80 and 100 mgs/mL shoulder observed
10
API in Drug Product
Expanded spectrum
Shoulder at 80 and 100 mgs/mL due to crystalline freebase.
Rapid measurements, quantitative estimation of solubility possible.
11
Amorphous API
1H
NMR was used
Rigid: Gaussian
Mobile: Lorentzian
Fitting provides quantitation
Amorphous content 22.5%
Extremely rapid measurements, quantitative
No chemical shift resolution
12
Amorphous API
31P
NMR
5 sec. delay
200 sec. delay
Stuck on pins of pinmill
Compact 10X 200MPa RT
Compact 10X 200MPa 85C
Phase Separated
Amorphous
10
5
0
-5
-10
10
5
0
-5
-10
Amorphous has a very short T1 ~ 250 ms
Crystal had a very long T1 ~ 25 sec
Material stuck on pins ~ 12 wt% amorphous
10X compaction at 200 MPa (RT) ~ 5 wt%
10X compaction at 200 MPa (85 oC) ~ 2 wt%
13
Amorphous API
Time = 0
2 weeks ambient
2 weeks 25C/60%RH
2 weeks 40C/75%RH
F
F
-90
-100
-110
-120
Broadening due to defects or phase separated amorphous??
-130
14
Amorphous API
M(tau)/M0= 1-2*exp(-tau/T1)
F
Each Phase in multi-phase system will yield
unique T1 value
F
Pure Crystalline
T1 = 5 seconds
Pure Amorphous
T1 = 1 second
-90
-100
-110
-120
-130
15
Amorphous API
Monitoring in-process samples
End of Drying Sample (MAS)
T1 Filter 2.55 sec
-90
-100
-110
-120
-130
Can detect amorphous content without any apriori knowledge of system.
Was also used identify presence of multiple crystalline phases
16
Amorphous API
Monitoring stability samples
Time = 0
2 weeks ambient
2 weeks 25C/60%RH
2 weeks 40C/75%RH
-90
•
•
•
•
-100
-110
-120
Intensity directly proportional to amorphous content
Qualitative amorphous content readily achieved
LOD exceedingly low (limited only by NMR time)
Quantitation requires calibration curve
-130
17
Intensity
DECRA
300
200
100
0
8
12
t (sec)
16
1.2
0.8
2.0
1.5
0.4
1.0

)
20
Intensity
Concentration
4
m
pp
d(

2.0
1.5
1.0
0.5
0.0
0.5
0.0
2
4
6
8
10 12
t (sec)
14
16
0.0
18
0
50
100
150
d (ppm)
I   C   P 
200
250
300
T
nxm
nxc
mxc
18
T1rho DECRA
Stability Sample
F
19F CP/MAS
F
Previous ID of
multiple Phases by
1H T
1rho Filter
-100
Conc
30x10
6
20
Component 1
39msec T1rho
35% of total spectra
-80
F
-60
-40
80x10
Amplitude = 3.5719e+07
T1 = 0.039329 sec
10
0
Component 2
200msec T1rho
65% of total spectra
6
Amplitude = 6.64693e+07
T1 = 0.201025 sec
60
40
20
0.05
8x10
-20
DECRA
Conc
1H
0.10
0.15
Time ()
0.20
0.25
0.30
0.05
-3
16x10
0.10
-3
0.15
Time ()
0.20
0.25
0.30
14
12
Intensity
Intensity
6
4
10
8
6
2
4
2
0
0
-100
-80
-60
ppm
-40
-20
-100
-80
-60
ppm
-40
19
-20
DECRA
Polymorph ID



API process involves desolvation to get the anhydrous form
Material forms amorphous on compaction
A second phase observed in 19F SSNMR spectra for different
batches
Similar XRPD and DSC

19F
Intensity (counts)
XRPD
CP/MAS
20000
15000
RT
Dried at 80 oC
10000
Dried 50C
Dried at 50 oC
Dried 80C
5000
Dried at 25 oC
-70
5
10
15
20
25
30
35
-80
-90
-100
-110
ppm
2Theta (°)
20
Can we quantify second phase
DECRA
DECRA
19F
-CF3
F-f
CP/MAS
002Z004
002Z005
002Z006
002Z007
002Z008
-70
Component 1
20msec T1rho
80% of total spectra
1H
ppm
-110
ppm
-75
Component 2
6msec T1rho
20% of total spectra
T1r DECRA
Amplitude = 1.07877e+08
T1 = 0.0196922 sec
Amplitude = 2.57469e+07
T1 = 0.00580073 sec
10
10
15
-3
Time (x10 )
-3
20
25
5
14x10
20
10
15
-3
Time (x10 )
-3
20
25
12
10
15
Intensity
Intensity
6
0
5
25x10
20x10
Conc
Conc
6
120x10
100
80
60
40
20
10
8
6
4
5
2
0
0
-150
-100
-50
ppm
0
-150
-100
-50
ppm
0
21
sl
ur
ry
in
sl
in
80
d
in
Z0
08
oC
ac
et
on
itr
ile
ur
ry
ur
ry
to
re
ce
ive
100
Z0
08
sl
he
at
ed
as
120
ac
et
ac
on
et
e
on
ehe
pt
an
Z0
e
22
Ip
ac
08
40
32
de
sl
ur
-7
so
ry
8l
v
2
at
in
e
Ip
at
ac
50
he
oC
at
ed
to
80
oC
Z0
08
Z0
06
Z0
06
Z0
06
Wt% of component
Driving Process Definition
DECRA
Component I
Component II
Component III
80
60
40
20
0
Wet milling in IPAc followed by Drying at 50 oC recommended
22
DECRA
My API doesn’t have a 19F
13C
140
120
1H
Component 1
193msec T1rho
78% of total spectra
T1r DECRA
Through 19F
CP/MAS
80
60
40
20
T1r DECRA
9
20x10
Amplitude = 9.69968e+10
T1 = 0.193092 sec
80
T1rho
Wt%
Comp 1
133
70
Comp 2
55
30
0
Component 2
91msec T1rho
22% of total spectra
Conc
Conc
100x10
100
1H
9
Amplitude = 2.71464e+10
T1 = 0.0945691 sec
10
60
0
40
0.05
0.10
0.15
0.20
0.05
0.10
-3
Time ()
0.15
0.20
Time ()
2.0x10
-3
2.5x10
1.5
Intensity
Intensity
2.0
1.5
1.0
1.0
0.5
0.5
0.0
0.0
140
120
100
80
ppm
60
40
20
0
140
120
100
80
ppm
60
40
20
0
23
Heteronuclear Dipolar Correlation

1H-13C, 1H-15N,
and 1H-23Na HETCOR spectra for a hydrated API
C14
C10
C8
C2
C13
C3
C4
C15
Na1
N9
N7
C5
13C
15N
23Na
1
2
3
H50
H60
H50
H60
4
H1NA
H1NB
H4
1H
H4
H9
H9
H7
H15
7
H4
8
H9
NH2
N1
H7
H7
O
H15
S
9
O
Cl
O
C1
C6
C2 11
C5
C3
12
13
155
150
145
13
140
135
C chemical shift
130
125
120
115
-265
-270
15
-275
N chemical shift
Cryst. Growth & Des., 2006, 6, 2333-2354.
10
0
23
-10
-20
Na chemical shift
Cl
C12
C11 C13
O
N9
N7
C4
160
Cl
Na
10
H7
Correlations indicate
atoms near in space
(~3 Å)
1
6
H chemical shift
5
N
H
C8
C10 C14
C15
N
H
3 H2O
-30
24
Amorphous Dispersions
= drug
Polymer
Polymer
Amorphous
domains
Solid amorphous
solution
Crystalline domains (large)
Polymer
Polymer
Crystalline
domains
Crystals observed visually
25
2D 1H-19F Correlation
F1,F2
 1H-19F CP-HETCOR easily proves
molecular association on the <
10 Å scale
 Experiments such as these take
1-2 hours to perform for typical
drug loads (20-60% w/w)
Diflunisal
0
2
aliphatics
4
6
aromatics
8
10
12
O
OH
500 s
OH
-95
14
1H
-2
chemical shift (ppm from TMS)
-4
16
-100 -105 -110 -115 -120 -125 -130
19F
chemical shift (ppm from CFCl 3)
PVP
-2
F
0
2
aliphatics
4
6
Solid amorphous
solution
N
O
aromatics
8
10
12
14
n
2 ms (spin diffusion)
-95
Mol. Pharmaceutics, 7, 1667–1691 (2010).
-100 -105 -110 -115 -120 -125 -130
19F
chemical shift (ppm from CFCl3)
16
1H
F
chemical shift (ppm from TMS)
-4
Amorphous Dispersions
 A dispersion that greatly improves the dissolution of tenoxicam
in water (via a high degree of supersaturation)
 Contains four discrete components
= tenoxicam (singly ionized)
= L-arginine (singly ionized)
= L-arginine (zwitterionized)
Polyvinylpyrrolidine
Solid amorphous
solution
J. Pharm. Sci. 2012, 101, 641-663.
Nanocrystallline dispersion
Ch
-1
ebselen
PVP-VA
0
C8
Ch
-1
aromatic-aliphatic
correlations
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
tSD = 100 ms
60
40
20
ebselen
Polymer
80
PVP-VA
180 160 140 120 100
Crystalline
Domains
~50 nm
aromatic-aliphatic
correlations
180 160 140 120 100
80
60
40
20
chemical shift (ppm from TMS)
Pharm. Res. 2012, 29, 1866-1881
180 160 140 120 100
80
60
40
13
20
-1
-1
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
tSD = 10 ms
13C
12
tSD = 1 ms
13
12
tSD = 50 ms
13
180 160 140 120 100
13C
80
60
40
chemical shift (ppm from TMS)
Ca
Cj C7
1H
C8
Cb,Cd,Cf
Cg,Ci
Cc
Ck
20
chemical shift (ppm from TMS)
13
chemical shift (ppm from TMS)
Ca
Cj C7
aromatics
Cb,Cd,Cf
Cg,Ci
Cc
Ck
1H
aromatics
Concluding Thoughts
 Multitude of options to characterize API and
drug product material
 Relaxation methodology very powerful
 Expanding into 2D offers significant structure
information
29