Laboratoire de Dynamique et Structure des Matériaux Moléculaires UMR 8024 Université de Lille 1-France SOLID STATE TRANSFORMATIONS OF PHARMACEUTICAL COMPOUNDS UPON MILLING: LACTOSE & MANNITOL (authorized version) V. Caron, J-F. Willart, R. Lefort, J. Lefebvre, M. Descamps PPXRD 08, Glasgow, 04-07 May 2009
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Phase transformations under milling In the field of A very active field of researches in metallurgy : Sursaturated solid solutions Amorphous alloys (i.e. pharmaceutical compounds) : Nanomaterials MOLECULAR MATERIALS NO Several theoretical approaches developed SYSTEMATIC but INVESTIGATIONS Description of transformation mechanisms Prediction of final states (theoretical or experimental) No universally accepted
Milling of pharmaceutical compounds Pharma field Milling Grain size Solubility, bioavailability G Milling : numerous contradictory effects No systematic investigations In spite of : Importancy of applications Tg Tm T Original aspects of molecular materials (Fundamental studies)
Molecular compounds specificities Contrast between : Weak inter-molecular interactions Strong intra-molecular interactions a b Low Symmetry Important size Molecules cells (often tricl., mono. or ortho.) Low melting temperatures Glass transition temperature close of RT T milling Low kinetics of cryst Easy Quench-Vitrification Very sensitive to mechanical and thermal perturbations
Transfo. on milling of pharmaceutical compounds Materials selection T g >T milling Lactose Tg = 115 C >T mi Mutarotation caramelization T milling RT Mannitol Tg = 13 C < T mi Rich polymorphism T g <T milling
Plan of speech I Milling Characteristics of milling experiments realized at the laboratory II Stable anhydrous α-lactose Solid-state amorphization of αl S Mutarotation ( 13 C NMR) III Mannitol Mannitol δ Mannitol β Polymorphic transformations
Characteristics of milling Pulverisette 7 Fritsch N 2 N 2 ZrO 2 N x 400 rpm milling (20min) pause (10min) Prevention of hygroscopy
Lactose possible solid-state forms Disaccharid often used in Pharmaceutical and Food industries 2 types of molecules of lactose : α-lactose β-lactose Various solid-state forms: Monohydrated α lactose (L α -H 2 O) (stable) Hygroscopic anhydrous α lactose Stable anhydrous α lactose (αl S ) Anhydrous β lactose Molecular compounds α/β with various stœchiometries
Problems encountered for producing amorphous lactose Thermal degradations and caramelization Mutarotation (in solution ) α-lactose β-lactose
Amorphization of αl S under milling NMR 1 H liq PXRD DSC Muta. α 5 C/min α α/β α β β crystal Before milling After recrys After 30h milling After 30 h milling Before milling degradations 7.0 6.5 6.0 10 15 20 25 3080 120 160 200 240 Ch. Shift (ppm) 2 θ (degrees) Temperature ( C) Crystalline α lactose milling Glassy α lactose without degradations recrys Crystalline α/β lactose
Solid-state NMR 13 C : characterization in situ % β Solid NMR C 1 gal C 4 glu C 1 gluc 4 gal 13 C C 1 glu αlactose C 1 glu βlactose Crystalline or amorphous states Intensity (a.u.) crys β lactose C 1 gal C1 glu C 4 gal C 1 glu C 4 glu crys α LS Detection mutarotation Quantification % β in situ 140 120 100 80 60 40 Chemical Shift (ppm) 20 % β = f(t C)
Mutarotation during heating of amorphous αl Solid NMR 132 C β α 13 C Intensity (a.u.) 102 C 85 C 63 C 21,5 C 120 100 80 60 40 Chemical Shift (ppm)
Milling amorphization local melting-quench 70 60 50 Irreversible Tg α/β crystal T = 85 C 55 50 β-lactose (%) 40 30 20 10 0 0 20 40 60 80 100 120 140 160 180 Glassy αl Mutarotation Temperature ( C) 13 C NMR Out of equilibrium Structural relaxation below Tg 30 0 1 2 3 4 Time (h) 13 C NMR T mil < 85 C < T m Local melting / quench 45 40 35 β-lactose (%)
No mutarotation during heating of crystalline αl S Solid NMR 13 C 160 C Intensity (a.u.) 71,5 C 18 C Crystalline αl S 120 100 80 Chemical Shift (ppm) 60 40
Mannitol Characteristics of Mannitol : Acyclic polyol present in seafood, fruits, mushrooms Used as excipient, sweetener, API G Tg = 13 C G liq G δ G α G β Adapted from Burger et al., J. Pharm. Sciences, 2000, 89, 457 0 C Tm δtm αtm β T ( C)
Polymorphic transformation under milling of Mβ and Mδ XRD αβ Mβ δ XRD Mδ αβ Non milled milled 10 h Non milled Milled 52 h, aging 5h milled 10 h, aging 8 days Milled 52 h, aging 17h 10 15 20 25 30 35 40 10 15 20 25 30 35 40 2 θ (degrees) 2 θ (degrees) Mannitol β Aging milling Mannitol α Mannitol β Mannitol δ Room T C
Interpretation of amorphization αl S under milling as a «Driven system*» T eff (1 Dbal T eff = T + ) Dch T eff T melt Milling αl S D bal > D ch T eff > T fusion T milling T Amorphization *Driven alloys, Martin et al, Solid State Physics, 50, p189 (1997)
Interpretations polymorphic transformations mannitol under milling as a Driven system G G liq Adapted from Burger et al., J. Pharm. Sciences, 2000, 89,457 G δ G α Single T eff > T fusion milling Mβ, Mδ glass stop glass Mα milling G β 2 T eff 0 C β Tm δtm αtm β T transition α δ α T ( C) T eff >T m Mβ, Mδ glass T eff < T m glass Mα
Conclusion Crystalline α lactose milling Glassy α lactose without degradations Local quench melting Glassy αl heating Mutarotation Irreversible at T < Tg Glassy αl Out of equilibrium Mannitol β Aging Milling Mannitol α Mannitol β Mannitol δ Room T C States reached are stationary states rather than thermodynamic equilibrium states
Acknowledgements Pr. Marc Descamps Dr. Jean-François Willart Dr. Ronan Lefort Pr. Jacques Lefebvre Dr. Patrick Derollez Mme. Florence Danede M. Dominique Prevost
Publications related to this presentation P. Zhang, N. Klymachyov, S. Brown, J.C. Ellington and P.J. Grandinetti, "Solid state 13C NMR investigations of the glycosidic linkage in a-a trehalose", Solid state Nuclear Magentic Resonance, 1998, 12, pp 221. J.F. Willart, V. Caron, R. Lefort, F. Danède, D. Prévost and M. Descamps, "Athermal character of the solid state amorphization of lactose induced by ball milling", Solid State Communications, 2004, 132, pp. 693. J. Lefebvre, J.F. Willart, V. Caron, R. Lefort, F. Affouard and F. Danede, "Structure determination of the 1/1 α/β mixed lactose by X-ray powder diffraction", Acta Cryst. B, 2005, 61, pp. 455. R. Lefort, V. Caron, J.F. Willart and M. Descamps, "Mutarotational kinetics and glass transition of lactose", Solid State Communications, 2006, 140, pp. 329.
Publications related to this presentation R. Lefort, A. De Gusseme, J.F. Willart, F. Danede and M. Descamps, "Solid State NMR and DSC methods for quantifying the amorphous content in solid dosage forms: an application to ball-milling of trehalose", International Journal of Pharmaceutics, 2004, 280, pp. 209. M. Descamps, J.F. Willart, E. Dudognon and V. Caron, Transformation of Pharmaceutical Compounds upon milling and comilling : The role of Tg, Journal of Pharmaceutical Sciences, 2007, 96, 00, pp. 1-10. J. Rodriguez-Carvajal, T. Roisnel, Fullprof 98 and WinPLOTR: New Windows 95/NT Application for Diffraction, Newletter 20, 1998. H.M. Rietveld, "Line profiles of neutron powder diffraction peaks for structure refinement", Acta Cryst, 1967, 22, pp 151. H.M. Rietveld, "A profile refinement method for nuclear and magnetic structures", J. Appl. Cryst., 1969, 2, pp 65.