Post on 18-Apr-2015
Current Methods of Raman
Spectroscopy in the
Pharmaceutical Industry
Dr Caroline Rodger
Associate Principle Scientist
Pharmaceutical Development
AstraZeneca Macclesfield
December 2011
Agenda
1. A brief review of the Pharma Industry I. What is a Pharmaceutical?
II. Statistics
III. What is a tablet?
IV. Regulatory
2. What is Raman Spectroscopy? I. Simple Theory
II. Advantages and Disadvantages
3. Current Uses of Raman Spectroscopy
4. Opportunities!
5. Conclusions
6. Discussion
Author | 00 Month Year 2 Set area descriptor | Sub level 1
What is a Pharmaceutical Company?
• Pharma companies provide drugs Licensed for use as medicines:
I. Invent II. Develop III. Launch IV. Produce V. Market
• Highly regulated Industry
• Patent environment
Author | 00 Month Year 3 Set area descriptor | Sub level 1
What is a Pharmaceutical Company?
• On average ~10 years to get drug to market
• On average 1 in 10000 NCE is launched as a drug
• Cost of getting one drug to market is over $1 billion!
• 3 in 20 approved drugs bring sufficient revenue to cover development costs
• 1 in 3 generates enough revenue to cover costs of previous failures
Author | 00 Month Year 4 Set area descriptor | Sub level 1
What is a „Pharmaceutical‟?
“A chemical drug or medicine”
• Drug substance: - Solids, liquids, spray dried solids, etc
• Medicine: - Tablets, granules, solutions, capsules, emulsions, dispersions, depots,
injections, inhalers etc
• Packaging: - Syringes, polymers, plastics, adhesives, inks & resins
Author | 00 Month Year 5 Set area descriptor | Sub level 1
What is a tablet?
6 Author | 00 Month Year Set area descriptor | Sub level 1
Active Pharmaceutical
ingredient: API
Filler:
Lactose, CaHPO4
Binder:
Lactose, cellulose
Disintegrant:
Crosspovidone, Starch
Coating:
TiO2, sugars,
plasticizers
Lubricant:
Stearic acids, Mg
Stearate
Drug substance and formulated product
• Drug substance can exist as different polymorph, salts, hydrates, solvates etc.
• Drug substance and Tablet production is complex and involves many stages
- Blending - granulation - staged additions - drying - compression forces - Storage
• Commonly 5-6 ingredients in one formulation
• Tablets are “homogenous” mixtures of excipients and drug
• Pharmaceuticals are complicated!
7 Author | 00 Month Year Set area descriptor | Sub level 1
Regulatory aspects
- Heavily regulated: to protect us...the patients - Each country has their own regulatory authority that requires a
separate dossier to gain approval to sell a medicine in their country
- Regulatory submissions are dominated by: - Well established analytical technique. i.e. Chromatography,
NMR, FTIR…
- Established and accepted methods of validation and calibration
- I am currently unaware of any primary method presented in a regulatory dossier by AZ using Raman spectroscopy
- Traditionally, regulatory authorities are conservative but things are changing...
8 Author | 00 Month Year Set area descriptor | Sub level 1
„Guidance‟ Bodies and Documentation
- Regulatory authorities: FDA, EMEA, PMDA
- Pharmacopeia‟s: - Country/territory focussed - A „book‟ listing established and accepted methods of
validation and calibration - Generally for end product testing - Limited guidance on Raman Spectroscopy! Generally
around calibration of instrumentation
- ICH: International Conference of Harmonisation - Focuses on quality, safety and efficacy - A coalition of regulatory authorities and industry - Minimises differences between different regulatory
authorities - Provides generic guidelines
9 Author | 00 Month Year Set area descriptor | Sub level 1
What is Raman Spectroscopy?
Raman scattering is associated with a change in the polarisability of a molecule
10 Author | 00 Month Year Set area descriptor | Sub level 1
Some molecules gives rise to absorption, some to Raman
scattering and others to both absorption and Raman scattering
What is Raman Spectroscopy?
11 Author | 00 Month Year Set area descriptor | Sub level 1
Rayleigh scattering
(filtered out)
Raman scattering
(Stokes shift)
LASER
200 400 600 800 1000 1200 1400 1600 1800 2000
Raman shift (cm-1)
Blo
ck
ing
Filte
r
0
Ex
cit
ati
on
fre
qu
en
cy
V = 0
Ra
yle
igh
sc
att
eri
ng
V = 1
Ram
an
sc
att
eri
ng
~~~~~~~~~~~~~~~ V = virtual
state
Advantages of Raman Spectroscopy
+ Sharp spectral features - Generally spectra have distinct peaks which can be readily
attributed to the API - Results in a high selectivity - Simplifies data modelling, easier to understand
+ Sensitive to solid state characteristics + Relatively insensitive to water
- Changes in humidity is not a problem - Can analysis solutions
+ Little or no sample prep required - No dissolving, grinding or pressure required hence integrety of
sample intact and solid state properties accessable - Small amount of sample required which saves valuable resource - Sample through packageing e.g blister pack, bottle, hot stage
microscopes etc
12 Author | 00 Month Year Set area descriptor | Sub level 1
Limitations of Raman Spectroscopy
- Weak effect - 1 in 106 photons Raman scattered
- Small sampling volume - May lead to sub-sampling within single samples
- Transmission Raman offers a potential solution?
- Sample heating, absorption
- Solid phase transitions?
- Preferential orientation issue - Poor reproducibility?
- Sometimes obstructed by fluorescence - Makes data evaluation more interesting
13 Author | 00 Month Year Set area descriptor | Sub level 1
Effect of fluorescence
14 Author | 00 Month Year Set area descriptor | Sub level 1
532 nm laser
785 nm laser
FT-Raman, 1064 nm laser
500 1000 1500 2000 2500 3000 3500
What is Raman used for in Pharma industry?
• Identification of raw material, intermediate, final products, packaging…
• Assessing polymorphism of compounds • Solid state properties, hydration, solvates, salts etc • Monitoring stability studies • Salt screens • Kinetic measurements • Qualitative and quantitative assessment of API and excipients
(UOC) • Investigation of contaminates and production problems • Assessing domain sizes • Reaction monitoring • Troubleshooting • Product verification • …
Very limited use of Raman spectroscopy in regulatory field!
15 Author | 00 Month Year Set area descriptor | Sub level 1
Solid state analysis Raman spectroscopy can be used to attain quantitative information about solid state forms of both the active and excipients
16 Author | 00 Month Year Set area descriptor | Sub level 1
3600.0 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400 200.0
cm-1
INT
Alpha lactose monohydrate
Beta lactose anhydrous
Solid State Analysis Possible to perform qualitative and quantitative assessments of drug forms
17 Author | 00 Month Year Set area descriptor | Sub level 1
Hydrate
Anhydrous
Solid State Analysis
18 Author | 00 Month Year Set area descriptor | Sub level 1
Hydrate
Anhydrous
Hydrate
Anhydrous
Specificity
19 Author | 00 Month Year Set area descriptor | Sub level 1
Anhydrous API
Hydrate API
Formulated Product
Placebo
High Throughput analysis
- Polymorph screening
- Non-destructive
- Automated data collection
- Automated data processing
- Automated data analysis
- Kinetic expt possible
20 Author | 00 Month Year Set area descriptor | Sub level 1
Raman Sampling Geometries
• Conventional appraoch is backscatter geometry (diffuse reflectance)
• Transmission geometry, long interaction length Transmission Raman spectroscopy, P. Matousek and A. W. Parker, Appl. Spectrosc. 60, 1353 (2006)
Transmitted
light
s
a
Incident
light
v-vib
v-vib
Diffusely
reflected
1) More homogenous
sampling
2) Longer optical
pathlength means higher
Raman signal
Where are AZ using Transmission Raman:
Rapid Quantification of Drug Product
• Instrument purchased in 2009 and located in Mölndal
• The aim was:
- An automated tool for whole sample analysis of up to 30
tablets or capsules that allows determination of content
uniformity and solid state form completed within one hour,
including sample loading and sample logging,
measurements, evaluation and report generation
Technology
• Instrument delivered to Mölndal November 2009
• Used in pilot projects
• Aspiration to transfer to operations sites
200 400 600 800 1000 1200 1400 1600 1800 20000
500
1000
1500
2000
2500
3000
3500
4000
4500
Raman shift (cm-1)
Ram
an inte
nsity
Propranolol-Mannitol, API=20 %w/w, Horiba instrument, t=1 s
Uniformity of content
Current Status
• Analysis of content and content uniformity done by current methods
takes much resources (primarily), and can be slow (secondary).
• Alternative fast spectroscopic methods can be complicated, time
consuming and need substantial maintenance.
• Chromatography:
• Work horse in pharma: Universally accepted
• Accurate results
• Slow
• Requires sample preparation
• Real Time Realease???
Uniformity of content
SPECTROSCOPY
• Near Infrared:
• Accepted by authorities
• Provides fast results with no sample preparation
• Suitable for in-line approach: Real Time Realease?
• Extensive calibration efforts, susceptible to changes in process parameters (good
or bad)
• Sensitivity issues?
• Raman
• Standard technique for solid state characterisation but, due to sampling issues,
hasn‟t been applied to UOC until now….
Uniformity of Content
Batch ID Content-TR
(% nom)
RSD-TR
(%)
AV-TR Content-LC
(% nom)
RSD-LC
(% nom)
AV-LC
#1-LD 99.7 2.0 4.8 99.7 1.0 2.3
#2-LD 99.1 1.9 4.6 100.1 1.3 3.1
#3-LD 98.6 2.1 5.1 98.8 0.7 1.7
#4-LD 99.6 2.2 5.4 98.4 0.7 2.0
#5-HD 100.6 1.2 2.8 99.6 1.0 2.4
#6-HD 99.8 1.0 2.3 97.9 0.7 2.0
#7-LD-C 100.3 1.6 3.8 98.8 1.6 3.7
#8-HD-C 97.3 0.90 3.4 97.3 1.1 3.7
Predictions were made with local calibrations, using MCR.
AV= acceptance value, calculated as 2.4*SD if mean is between 98.5-101.5% and n=10, otherwise a penalty is added; [98.5-mean] or [mean-101.5]
• LC and TR correlate • AV comparable to LC
UOC: possible in a regulatory environment
• Proof of principle has been carried out on several projects
• Key conclusions:
• API >1 % detection limit
• MCC < 75 % or issues with fluorescence
• Preferably uncoated tablets (coated possible but may
effect sensitivity
• Possible to assess 60 tablets in one hour
• Comparable to LC in most cases but will not completely
replace LC!
Raman imaging in the pharmaceutical
industry • Raman imaging has traditionally been limited by:
- Time required to sample a statistically representative area
- Complexity of data processing
- Subjectivity of comparing images
• This may be overcome by:
- Fast Raman imaging – Allows large areas to be sampled but data
processing may still be problematic
- Reduced data collection – „lean‟ Raman imaging
• Principles of „lean‟ Raman imaging:
- 1 dimensional data collection – line scans
- Simple, automated data processing – univariate where possible
- Statistical analysis to extract numerical descriptors of the sample
Raman Imaging
29 Author | 00 Month Year Set area descriptor | Sub level 1
sample
laser
mapping
Obtained Raman
spectrum
Chemical Image
Raman Imaging
30 Author | 00 Month Year Set area descriptor | Sub level 1
200 400 600 800 1000 1200 1400 1600 18000
500
1000
1500
2000
2500
3000
3500
Wavenumber (cm-1)
MCC
200 400 600 800 1000 1200 1400 1600 18000
1000
2000
3000
4000
5000
6000
Wavenumber (cm-1)
Lactose
200 400 600 800 1000 1200 1400 1600 18000
500
1000
1500
2000
2500
3000
Wavenumber (cm-1)
Salicylic acid
Raman: Lean Imaging for assessing sedimentation
Problem:
- A semi solid dispersion of a drug and
polymer displays different dissolution
profiles:
Author | 00 Month Year 31
Raman spectra of Drug
and polymer can clearly be
differentiated
0
500
1000
1500
2000
2500
3000
3500
200300400500600700800900
Raman Shift (cm-1)
Inte
nsity
API
Polymer
277 cm-1
713 cm-1
0
500
1000
1500
2000
2500
3000
3500
200300400500600700800900
Raman Shift (cm-1)
Inte
nsity
API
Polymer
277 cm-1
713 cm-1
Peak Ratio: Peak height @ 713cm-1
Peak height @ 277cm-1
Raman: Lean Imaging for assessing sedimentation
To quantify sedimentation of drug: • Calculate the average ratio of the peaks at 713cm-1 and 277cm-1 for each
line scan • Calculate the standard deviation of the six peak ratios
Author | 00 Month Year 32 Set area descriptor | Sub level 1
Mean = 0.97
%RSD = 75.41
As sedimentation
increases the
standard deviation
increases
1. Rapid Screening Method for Sedimentation –
Method Validation
• Method validated by HPLC - each capsule was cut into 4 and assayed
• Good agreement was obtained between the Raman and HPLC data
• RMSEP of 5% for Raman method
1. Rapid Screening Method for Sedimentation -
Results
•Two batches showing „good‟
dissolution profiles (batches A
and B) and two batches
showing poor dissolution
profiles (batches C and D)
were mapped to assess
sedimentation.
0
20
40
60
80
100
0 10 20 30 40 50 60
Time (mins)
Dis
so
luti
on
(%
)
Batch A
Batch B
Batch C
Batch D
•Analysis of the 95%
confidence intervals
for all good batches
tested shows: Peak
ratio RSD < 10%
indicates the
sample that has not
undergone
significant
sedimentation.
1. Rapid Screening Method for Sedimentation -
Conclusions
• Rapid Raman screening method provides: • Efficiency gains over HPLC (approx 15 mins per sample)
• Minimal sample preparation and handling
• Improved spatial information over wet chemistry techniques
• New approach to vibrational imaging: • Rapid, fit for purpose method
• Data collection minimised – only collect the critical information
about the sample
• Simple statistical analysis: • Simple, rapid data analysis
• Numerical measure of sedimentation – allows ranking of samples
and setting of specifications
Raman imaging in the pharmaceutical
industry
New
Image
Descriptor
s
Objective – Use fast and/or „lean‟ Raman mapping approaches to generate rapid, fit for purpose methods
Process Analytics
Part of an army of technologies…
37
UV-Vis Lasentec Raman NIR
38
• Formation of the amide intermediate is rapid (<5 mins)
• In earlier campaigns, a 90h Dean and Stark distillation was used to
remove water formed during the conversion to cyclised product. - This was replaced with 3 solvent replacement cycles to remove wet solvent and
replace with fresh, dry solvent.
• Rate of conversion was very sensitive to temperature/pressure.
• Had never run this new process on scale before. - During the 3 solvent replacement cycles, the current extent of conversion
would be unknown. Sampling would be time consuming.
NH2
NH2
R'''n
O
R'O R"O
NH NH2
R'''
R"n
N
NH
R'''
R"
n
3 x "Put & Take" with Solvent
110 - 130C~800 mbar
1.0 eq.
Solvent
'Amide'
Example 1: Monitoring a cyclisation
reaction
Example 1: Monitoring a cyclisation
reaction
• Raman spectroscopy exhibited good selectivity for both the amide intermediate and the cyclised product.
• Only simple baseline correction and spectral normalisation required to pre-process spectra.
• Linear regression applied to correlate Raman peak ratio to GC peak ratio using samples taken after each solvent replacement step.
Raman spectra collected during
laboratory development.
Intermediate amide
Product
A B
C
D
Ra
tio
Pro
du
ct
: A
mid
e
Maintaining a constant ~800 mbar proved very difficult in the pilot
plant.
Higher vacuum caused solvent to distil at a lower temperature,
leading to poor rate of conversion – in-situ Raman prediction
provided early warning(A)
Based on in-situ Raman results, distillation was performed at
atmospheric pressure (C and D).
Example 1: Monitoring a cyclisation reaction
Plot of predicted
conversion was
provided in real-time.
When sampled for final
off-line analysis, the
end-of-reaction criterion
was met (>99% product).
Example 2: Rapid Product Development Tool
41 Author | 00 Month Year Set area descriptor | Sub level 1
Raman and NIR sampling workflow
Store
Move
Measure
•Powders, solutions, tablets and
capsules
•Chemical and Physical stability
•Flexible temperature, humidity &
photostability
•Suite of analytical tools –
•Raman
•NIR
•UPLC-UV-ELSD-MS
•sample prep
•optical images
•weight
•oxygen level
Product Verification:
Development of a portable Raman device for remote
identification of Drug Product
Business Benefits: • Rapid, Non destructive remote/mobile testing • Valuable tool to AZ product security Current success: • Deployed international within AZ Product security
Areas of AZ this impacts on: • Raw material testing: CS, Supply Chain, AS, FS,
Operations • Clinical material testing: Supply Chain • Product security: Operations Effort/costs to achieve the benefits: • ~6 devices within product security and one master
within AS
Author | 00 Month Year 42 Set area descriptor | Sub level 1
Product Verification: The device….
43 Author | 00 Month Year Set area descriptor | Sub level 1
(a) (b) (c)
Vial slides in/out
Product Verification: work flow
44 Author | 00 Month Year Set area descriptor | Sub level 1
suspect
sample
Sensor
device
0
10000
20000
30000
40000
1600 1400 1200 1000 800 600 400
Intensity / Raman Shift (cm-1)
638
516
395
spectrum for suspect
sample
interrogate
database
database
Contains
spectra for
reference
samples
output
List of best „hits‟
based on a
correlation
function. Not
always
unequivocal
A unique and valuable addition to the toolbox
technology for product verification
Opportunities: ICH 8, 9 and 10….
45 Author | 00 Month Year Set area descriptor | Sub level 1
ICH Q8/Q8(R) -Pharmaceutical Development: Product and Process understanding (Design space and flexible regulatory approaches)
ICH Q10 – Pharmaceutical Quality Systems
Track, trend and respond to product quality
ICH Q9 –Quality Risk Management:
Couples sound science with risk management tools: risk –v- quality
FDA PAT Guidance
What is Quality by Design?
Key aspects: Quality CAN NOT be tested into products rather it
should be designed or planned
1. By design of effective and efficient manufacturing processes
product quality and performance are guarenteed
2. Product and process specifications are based on a mechanistic
understanding of how formulation and process factors affect
product performance
3. Quality assurance is continuous and real time
4. Relevant regulatory policies and procedures are tailored to
accommodate the most current level of scientific knowledge
5. Risk-based regulatory approaches recognize both the level of
scientific understanding and the capability of process control related
to product quality and performance
Raman Spectroscopy has a role to play!
46 Author | 00 Month Year Set area descriptor | Sub level 1
Critical Quality Attributes The attributes that have been determined to be necessary to ensure the safety and efficacy of product tablets.
CQA Analyte/test Target value Confirmed on spec
Physical state Description A white to off-white powder Yes
Identification FTIR (DRIFT) or NIR Consistent with the reference standard Yes
Assay HPLC 98%-102% w/w Yes
Organic purity Impurity C 0.20% w/w maximum Yes
Impurity D 0.15% w/w maximum Yes
Des Methyl 0.10% w/w maximum No
Genotoxic impurities 5 ppm maximum each (TTC level) No
Any individual unspecified impurity 0.10% w/w maximum Yes
Total organic impurities 0.5% w/w maximum Yes
Residual solvents Solvent 5000 ppm maximum No
Solvent 5000 ppm maximum No
Solvent 720 ppm maximum Yes
Solvent 3000 ppm maximum No
Formaldehyde 9 mg/day TDI No
Formic acid 5000 ppm maximum No
Solvent 530 ppm maximum No
Solvent 890 ppm maximum No
Water content Karl Fischer 0.2% w/w maximum No
Metal content Heavy metal 100 ppm maximum No
Heavy metal 50 ppm maximum No
Inorganic purity Residue on ignition/sulphated ash 0.1% w/w maximum No
Particle size distribution D (v, 0.1) 5 microns maximum Yes
D (v, 0.5) 14 microns maximum Yes
D (v, 0.9) 52 microns maximum Yes
Polymorphic form X-ray powder diffraction Form 1 No
Microbial purity Bioburden <10 cfu per gram No
TTC Threshold of toxicological concern. TDI Tolerable daily intake.
48
Raw Materials
Reaction
Quench
Dist/SolvSwap
Crystallisation
Filter
Dry
Clean
Raw Materials
Reaction
Quench
Dist/SolvSwap
Crystallisation
Filter
Dry
Clean
Raw Materials
Reaction
Quench
Dist/SolvSwap
Crystallisation
Filter
Wet Mill
Dry API
Clean
Inte
rme
dia
te A
Inte
rme
dia
te B
Crude/API
Excipients
Blend
Granulate
FBD
Granules Excipients
Blend
Compression
Coating
Product
Characterisation
Dru
g P
rod
uc
t
Characterisation
•Particle Size
•Moisture Content
•Purity
•Flow Properties
Blend Homogeneity
Moisture Distribution
Moisture Analysis
Drug Assay in Granulation
Granule Hardness
Drug Assay in Granulation
Post Blending Segregation
Drug Assay in tablet cores
Coating Thickness
Drug Assay in coated tablets
Content uniformity
Disintegration time
Dissolution
Hardness
Packaging
Process NCRM ID
EOR/Steady State
Conversion
Solution Assay
Titrate
Hydrogenation
Kinetics
Endpoint
Continuous Addition
Solution Assay
Loss to liquors
Supersaturation
Particle Size
Steady State
Polymorph
Kinetics
Particle Size
Solvent saturation
Cleaning Endpoint Drying end-point
Where can Raman Spectroscopy add value for
QDB • Limited/no sample prep:
• A place for Raman on/at line to monitor & control quality • Automation?
• Process Analytics • Deliver robust processes, quality and control
• Selectivity: Raman has the potential to rapidly probe: • Qualitative and Quantitative assessments (UOC) • Solid state properties • Real Time Release?
• Imaging • Monitoring quality of output? • Real Time release?
• Rapid Analysis: Method are quick and robust: • fast response to deviation from design space • Maintain quality • Minimise risk
Author | 00 Month Year 49 Set area descriptor | Sub level 1
Conclusions
• There is a growing and important role for Raman Spectroscopy within the Pharmaceutical Industry
• Specialist must understand opportunities and work together within the industry, academics, vendors and regulatory authorities to maxmise benefit and utilisation
Key to success • Requirement to increase skills and uptake of Raman
spectroscopy in operation areas. Is cost still a barrier?
• Engage, partner and educate regulatory authorities
Author | 00 Month Year 50 Set area descriptor | Sub level 1
Acknowledgements….
AZ: Steph Brookes Andy Brookes Kevin Sutcliffe Nick Pedge Rich Hart Jonas Johansson Olof Svensson Anders Sparen Horiba: Mike Claybourn Thermo: David James
Author | 00 Month Year 51 Set area descriptor | Sub level 1
52 Author | 00 Month Year Set area descriptor | Sub level 1
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