Powder X-Ray Diffraction and its Applications in Pharmaceutical Industry Shawn Yin, Ph. D. Drug Product Science & Technology Research & Development Bristol-Myers Squibb Co. USA NYU XRD Workshop, New York University June, 2014 1
Outline Pharmaceutical substances PXRD & other physical characterization technologies When and where to use PXRD in pharmaceutical industry PXRD Pharmaceutical Applications
Bulk Pharmaceutical Substances Pharmaceutical solid substances: API or API like materials (intermediates), excipients, mixtures (granules, tablets), etc. Physical States: Crystalline, amorphous, their mixtures (semicrystalline) and liquid crystal Properties: Stability, solubility, crystallinity, hygroscopicity, dissolution rate, bioavailability, powder properties, etc.
Crystalline and Amorphous Solids Crystalline: Solid having a regularly repeating arrangement of the chemical entity Examples: table salt, graphite, lactose monohydrate, Aripiprazole API etc. Amorphous: Solid that lacks long-range order of the chemical entity Examples: window glass, cotton candy, HPMC and other cellulous containing materials, Amorphous Warfarin Sodium API etc.
Polymorphism Polymorphism is the propensity of a substance to crystallize into more than one crystal structure As expected, different polymorphic forms will have different properties Example: BMS- 337039 (Aripiprazole) S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010
Pseudo-polymorphism S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010 Polymorphic solvates/ Solvatomorp hism : a transformation to another crystal structure takes place upon desolvation and resolvation; Pseudopolymorphism : the crystalline structure is maintained upon desolvation and resolvation Chemical composition is not the same Example: BMS- 337039 (Aripiprazole)
Pharmaceutical Polymorphism (by Regulatory Agencies) Polymorphism refers to the occurrence of different crystalline forms of the same drug substance Polymorphism (in this commentary) is defined as in the International Conference on Harmonization (ICH) Guideline Q6A (2), to include solvation products and amorphous forms. http://www.fda.gov/ohrms/dockets/ac/02/briefing/3900b1_04_po lymorphism.htm
Viewing Materials Through Different Lenses Bulk (Macro-) Level: one batch of Abilify API material size range: larger than 100 microns viewing by biologic lens - naked eyes Particulate (Meso-) Level: crystals of NaCl size range: sub microns to microns viewing through mechanic lens - microscopes Atomic/Molecular (Micro-) Level: molecules of Aripiprazole size range: less than 100Å physically not visible by common means (but indirectly by mathematic lens - single crystal structure through Fourier Transformation)
Common Technologies for Solid-State Characterization Diffraction (single crystal/powder) X-ray, neutron, electron Thermal analysis DSC (DTA), TGA, TSC, TMA, DMA, etc. Spectroscopic IR, NIR, Raman, SSNMR, etc. Micromeritics Surface Area, Particle Size, igc, Vapor Sorption, etc. Microscopy Optical, SEM, TEM, STM, AFM, etc. Combinations Hot-stage microscopy, VT-PXRD/DSC, TG-IR/MS etc. Multi-disciplinary approaches
Powder X-ray Diffraction incident beam diffracted beam q q q d Bragg s Law: 2 d sin q = n q = incident angle, = wavelength, d = spacing of crystal planes
2 Dimension Diffraction Cones Courtesy of Bruker-AXS
Powder X-ray Diffraction (from diffraction cones to PXRD pattern) Peak position: determined by the size of unit cell of crystal structure Peak intensity: determined by the contents of the unit cell
Single Crystal X-ray Diffraction & Crystal Structures Measure observed intensity I (hkl) K F 2 (hkl) where K = scale factor and other set-up coefficients Extract structure factor F(hkl) obs = f N exp[2 i(hx N + ky N + lz N )] Perform reverse Fourier transformation (xyz) = (1/V c ) F(hkl) exp[-2 i(hx N + ky N + lz N )] Extract atomic coordinates x,y,z 3D reciprocal space to 3D direct space for single crystal work
Simulating Powder XRD Patterns from Crystal Structures Solve (or model) crystal structure: Derive atomic coordinates (xyz) (or from Cambridge Database) Structure factor: F(hkl) cal = f N exp[2 i(hx N + ky N + lz N )] or F(hkl) obs 3D calculated intensities (hkl): I (hkl) K F 2 (hkl) 1D calculated intensities (2q): I (2q) = K L(q) I (hkl) A(q) Bragg s Law: 2 d sin q = n where I(q) is associated to I(hkl) by the relationships of (hkl), d and then Bragg s Law 3D direct space to 1D reciprocal space for PXRD Squeezing 3D into 1D (single crystal vs. powder diffraction data) 14
Examples: Polymorphism & Pseudo Polymorphism Intensity(Counts) 7000 6000 5000 4000 3000 2000 Observed N-6 Simulated N-6 Observed N-5 Simulated N-5 Observed N-4 Simulated N-4 Observed N-3 (via VT-PXRD) Simulated N-3 Observed N-2 Simulated N-2 1000 0 Observed N-1 Simulated N-1 Observed H-0 Simulated H-0 5 10 15 20 25 30 2-Theta( ) S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010
Common Pharmaceutical Applications of PXRD PXRD is a primary, non-destructive, crystal form identification technique, for API and drug product: Qualitative (most of time) Quantitative form composition determination Pure form or mixture of forms Large or small sample quantity Simple or no sample preparation Crystallinity of solid materials (crystalline vs. amorphous) Average crystallite size analysis (for crystallite size in the sub-micron to nanometer ranges) Solving crystal structures from powder diffraction data Powder pattern indexing for form homogeneity Confirming reference standards for secondary techniques (FT-IR/NIR/Raman, SSNMR, DSC, etc.)
Drug Discovery & Development Stages - when & where to use PXRD Discovery to early exploratory development Crystalline or amorphous Structure ID for crystalline materials (usually requires crystal structure) Early exploratory development up to First in Human/Phase I Polymorphic/salt form screening (HTC and/or manual) and final form selection for development Comprehensive physical characterization for critical and process relevant forms Data for IND filling/form patent Late Stage/Phase II/III Assisting process and formulation development activities: thermodynamics and kinetics of relevant forms; API scale-up; API & DP LTSS; API form ID & crystallinity in DP; etc. Method development for technology transfer Data for CMC section of NDA filling Post-approval/Life cycle management New formulation development Trouble-shooting for manufacturing issues
Intensity(Counts) API Drying Process Control 1250 1000 750 Simulated N-3 500 250 Observed LTSS Batch 0 Simulated H-1 5 10 15 20 25 30 2-Theta( ) S. Yin et. al., Opinion in Drug Discovery & Development, 11(6), 771-777 (2008)
API Drying Process Control a H2 O s RH a H 2Ov Slurry a H2 O l At equilibrium: a v = a l = a critical A H2O A + H2O Vary H 2 O in slurry while observing form conversion Slurry approach minimizes mass transfer concerns Checked form by slurry PXRD: H-1 -> N-3 favored for RH < 2%; N-3 -> H-1 favored for RH > 9% On scale process drying studies suggested the same RH range for conversions between H-1/N-3 Preliminary results indicate ~4.5%RH is thermodynamic limit (estimated with slurry exp., KF data and VLE calculator)
Dewpoint ( C) API Drying Process Control -5.0-10.0-15.0 Thermodynamically Safe Zone -20.0-25.0 Tdp = 0.6954*Tcake-35.727-30.0 0 10 20 30 40 50 Temperature ( C) S. Yin et. al., Opinion in Drug Discovery & Development, 11(6), 771-777 (2008)
Intensity(Counts) API Drying Process Control 7500 Simulated N-3 LTSS Batch #7 5000 2500 0 LTSS Batch #6 LTSS Batch #5 LTSS Batch #4 LTSS Batch #3 LTSS Batch #2 LTSS Batch #1b LTSS Batch #1 Simulated H-1 5 10 15 20 25 30 2-Theta( ) S. Yin et. al., Opinion in Drug Discovery & Development, 11(6), 771-777 (2008)
Thermal Study - Variable Temperature PXRD - Problems Sample displacement shift due to sample movement Cell expansion (contraction) due to temperature change Possible phase transition(s) Possible degradation at elevated temperatures
Intensity(Counts) Simulated vs. Observed PXRD Patterns - Refine the simulated pattern 2000 1500 Simulated -50C 1000 Observed 500 Simulated - refined at 25C 0 5 10 15 20 25 30 2-Theta( ) Theta( ) S. Yin et. al., American Pharmaceutical Review, Vol.8, Issue 2, p56-62, (2005) hybrid
Intensity(Counts) Thermal Study - Variable Temperature PXRD 2000 1500 Simulated Solvent-Free Form I 100C 1000 Observed 100C 500 Observed RT 0 "Hydrid" Hydrate RT 10 15 20 25 30 2-Theta( ) S. Yin et. al., American Pharmaceutical Review, Vol.8, Issue 2, p56-62, (2005)
Weight (%) Heat Flow (W/g) Deriv. Weight (%/ C) Heat Flow (W/g) Thermal Study - Variable Temperature PXRD - Thermal Analysis Confirmation 110 0 100 0.8-2 0.6 90 0.04 0.02 181.00 C 0.00-0.02 0.4-4 80-0.04 158.85 C 4.621J/g -0.06 140 150 160 170 180 190 200 Exo Up Temperature ( C) Universal V3.6C TA Instruments 0.2 70 0.0-6 60 Exo Up -8 0 50 100 150 200 250 300 350 Temperature ( C) Universal V2.5H TA Instruments S. Yin et. al., American Pharmaceutical Review, Vol.8, Issue 2, p56-62, (2005)
Intensity(Counts) Thermal Study - Variable Temperature PXRD 2500 Simulated Solvent-Free Form II RT 2000 Observed 25C (cooled) 1500 Observed 175C 1000 Simulated Solvent-Free Form I 100C 500 0 Observed 100C 10 15 20 25 30 2-T heta( ) S. Yin et. al., American Pharmaceutical Review, Vol.8, Issue 2, p56-62, (2005)
What are the API Forms in Drug Product? 27
API Crystal Form in Drug Product - PXRD Patterns Intensity(Counts) ] Blue - Simulated HCl Salt Hydrate I 21-1272> Anatase, syn - TiO2 250 200 Brown - Simulated HCl Salt Hydrate II Red Red - 200 200 mg tablet mg tablet Green - TiO2 150 TiO2 100 50 Talc 0 5 10 15 20 25 30 2-Theta( ) S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010
API Crystal Form in Drug Product - NIR Spectrum HCl salt hydrate II Talc S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010
API Crystal Form in Drug Product - NIR Spectrum HCl salt hydrate II HCl salt hydrate I S. Yin, 9th Annual Polymorphism & Crystallization Scientific Forum, Phila, PA, 2010
Spray Drying Pharmaceutical Ingredients 31
Intensity(Counts) PXRD Patterns of Spray Dried Samples 3500 3000 BMS-347070 2500 90:10 Drug:Pluronic 2000 1500 50:50 Drug:Pluronic 1000 20:80 Drug:Pluronic 500 0 Pluronic F127 5 10 15 20 25 30 2-Theta( ) Both crystalline drug and Pluronic are found in the SDD samples by PXRD The metastable API form was formed in the system * S. Yin et. al. J. Pharm. Sci., 2005, Vol. 94, No. 7, 1598-1607 32
DSC Thermograms of Spray Dried Samples Both crystalline drug and Pluronic are found in the SDD samples by DSC * S. Yin et. al. J. Pharm. Sci., 2005, Vol. 94, No. 7, 1598-1607 33
Intensity(Counts) PXRD Patterns of SDD Samples [34094.SD] 347070 48244070 <2T(0)=-0.054> [34095.SD] 347070 4824406222 <2T(0)=-0.052> [33531.SD] 347070 FORM N1 750 20:80 SP 500 50:50 SP 250 90:10 SP 0 pure drug 13 14 15 16 17 18 2-T heta( ) S. Yin et. al. J. Pharm. Sci., 2005, Vol. 94, No. 7, 1598-1607 34
Scherrer s Equation = (K )/( cosq) - crystallite dimension K shape factor (~0.9) ; - the wavelength; - line broadening due to the effect of small crystallites Base on Scherrer s equation, the crystallite size reduction of crystalline drug (assuming that all the peak broadening is caused by crystallite size reduction): Pure drug (averaged above 5 m) > Pluronic SP (averaged ~ 60 nm) 35
Time Evolution of PXRD 10.0 8.0 6.0 4.0 2.0 x10^3 15 20 25 30 35 2-Theta( ) Min. 15 30 45 60 75 90 105 120 135 a 50:50 drug:pluronic F127 film cast from acetone * S. Yin et. al. J. Pharm. Sci., 2005, Vol. 94, No. 7, 1598-1607 36
Proposed Model for Nano-sized Crystalline Drug * S. Yin et. al. J. Pharm. Sci., 2005, Vol. 94, No. 7, 1598-1607 37
Summary PXRD is a primary and most common technique for API form/phase studies PXRD plays a very important role in all stages of pharmaceutical research and development However, the multi-disciplinary/technique approach should be used as the best practice 38