Physical stabilization of low-molecular-weight amorphous drugs in the solid state: a material science approach.

Use of the amorphous state is considered to be one of the most effective approaches for improving the dissolution and subsequent oral bioavailability of poorly water-soluble drugs. However as the amorphous state has much higher physical instability in comparison with its crystalline counterpart, stabilization of amorphous drugs in a solid-dosage form presents a major challenge to formulators. The currently used approaches for stabilizing amorphous drug are discussed in this article with respect to their preparation, mechanism of stabilization and limitations. In order to realize the potential of amorphous formulations, significant efforts are required to enable the prediction of formulation performance. This will facilitate the development of computational tools that can inform a rapid and rational formulation development process for amorphous drugs.

[1]  C. Branford-White,et al.  Third generation solid dispersions of ferulic acid in electrospun composite nanofibers. , 2010, International journal of pharmaceutics.

[2]  Zhiping Zhang,et al.  The applications of Vitamin E TPGS in drug delivery. , 2013, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[3]  F. Lombardo,et al.  Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings , 1997 .

[4]  E. Munson,et al.  Investigating miscibility and molecular mobility of nifedipine-PVP amorphous solid dispersions using solid-state NMR spectroscopy. , 2014, Molecular pharmaceutics.

[5]  A. Chow,et al.  Production and characterization of a spray-dried hydroxypropyl-β-cyclodextrin/quercetin complex , 2009, Drug development and industrial pharmacy.

[6]  Bruno C. Hancock,et al.  Characteristics and significance of the amorphous state in pharmaceutical systems. , 1997, Journal of pharmaceutical sciences.

[7]  R. Suryanarayanan,et al.  Molecular mobility as an effective predictor of the physical stability of amorphous trehalose. , 2012, Molecular pharmaceutics.

[8]  J Dressman,et al.  Improving drug solubility for oral delivery using solid dispersions. , 2000, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[9]  M. Lauer,et al.  Rapid Assessment of Homogeneity and Stability of Amorphous Solid Dispersions by Atomic Force Microscopy—From Bench to Batch , 2013, Pharmaceutical Research.

[10]  Michael J. Pikal,et al.  Dynamics of pharmaceutical amorphous solids: the study of enthalpy relaxation by isothermal microcalorimetry. , 2002, Journal of pharmaceutical sciences.

[11]  Mark E. Davis,et al.  Studies on mesoporous materials II. Synthesis mechanism of MCM-41 , 1993 .

[12]  F. Vogt,et al.  Analysis of amorphous solid dispersions using 2D solid-state NMR and (1)H T(1) relaxation measurements. , 2010, Molecular pharmaceutics.

[13]  J. S. Beck,et al.  Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism , 1992, Nature.

[14]  R. Bogner,et al.  Complex effects of drug/silicate ratio, solid-state equivalent pH, and moisture on chemical stability of amorphous quinapril hydrochloride coground with silicates. , 2011, Journal of pharmaceutical sciences.

[15]  Michael J. Pikal,et al.  Solubility Advantage of Amorphous Pharmaceuticals: II. Application of Quantitative Thermodynamic Relationships for Prediction of Solubility Enhancement in Structurally Diverse Insoluble Pharmaceuticals , 2010, Pharmaceutical Research.

[16]  George Zografi,et al.  The molecular basis of moisture effects on the physical and chemical stability of drugs in the solid state , 1990 .

[17]  Deliang Zhou,et al.  Physical stability of amorphous pharmaceuticals: Importance of configurational thermodynamic quantities and molecular mobility. , 2002, Journal of pharmaceutical sciences.

[18]  Gareth R. Williams,et al.  Mebeverine-loaded electrospun nanofibers: physicochemical characterization and dissolution studies. , 2014, Journal of pharmaceutical sciences.

[19]  D. Craig A review of thermal methods used for the analysis of the crystal form, solution thermodynamics and glass transition behaviour of polyethylene glycols , 1995 .

[21]  Michael J. Pikal,et al.  Emerging Freeze-Drying Process Development and Scale-up Issues , 2011, AAPS PharmSciTech.

[22]  Y. Yoshihashi,et al.  Cocrystallization and amorphization induced by drug-excipient interaction improves the physical properties of acyclovir. , 2012, International journal of pharmaceutics.

[23]  Aditya Mohan Kaushal,et al.  Molecular and thermodynamic aspects of solubility advantage from solid dispersions. , 2007, Molecular pharmaceutics.

[24]  S. Yoshioka,et al.  Correlations between molecular mobility and chemical stability during storage of amorphous pharmaceuticals. , 2007, Journal of pharmaceutical sciences.

[25]  Han‐Gon Choi,et al.  Enhanced dissolution of ibuprofen using solid dispersion with poloxamer 407 , 2008, Archives of pharmacal research.

[26]  K. Sekiguchi,et al.  STUDIES ON ABSORPTION OF EUTECTIC MIXTURE. II. ABSORPTION OF FUSED CONGLOMERATES OF CHLORAMPHENICOL AND UREA IN RABBITS. , 1964, Chemical & pharmaceutical bulletin.

[27]  R. Müller,et al.  Nanosuspensions as particulate drug formulations in therapy. Rationale for development and what we can expect for the future. , 2001, Advanced drug delivery reviews.

[28]  C. Lipinski Drug-like properties and the causes of poor solubility and poor permeability. , 2000, Journal of pharmacological and toxicological methods.

[29]  Bradley F. Chmelka,et al.  Nonionic Triblock and Star Diblock Copolymer and Oligomeric Surfactant Syntheses of Highly Ordered, Hydrothermally Stable, Mesoporous Silica Structures , 1998 .

[30]  Gareth R. Williams,et al.  Electrospun nanofibers in drug delivery: recent developments and perspectives. , 2012, Therapeutic delivery.

[31]  Amrit Paudel,et al.  Theoretical and experimental investigation on the solid solubility and miscibility of naproxen in poly(vinylpyrrolidone). , 2010, Molecular pharmaceutics.

[32]  J. Rantanen,et al.  Characterisation of blends of paracetamol and citric acid , 2007, The Journal of pharmacy and pharmacology.

[33]  Jean-Marie Devoisselle,et al.  Solid-State NMR Study of Ibuprofen Confined in MCM-41 Material , 2006 .

[34]  D. Craig,et al.  The mechanisms of drug release from solid dispersions in water-soluble polymers. , 2002, International journal of pharmaceutics.

[35]  M. B. James,et al.  Preparation of glass solutions of three poorly water soluble drugs by spray drying, melt extrusion and ball milling. , 2007, International journal of pharmaceutics.

[36]  Jing Wang,et al.  Facile synthesis of 3D cubic mesoporous silica microspheres with a controllable pore size and their application for improved delivery of a water-insoluble drug. , 2011, Journal of colloid and interface science.

[37]  Y. K. Choi,et al.  Enhanced solubility and oral bioavailability of itraconazole by combining membrane emulsification and spray drying technique. , 2012, International journal of pharmaceutics.

[38]  J. Crison,et al.  A Theoretical Basis for a Biopharmaceutic Drug Classification: The Correlation of in Vitro Drug Product Dissolution and in Vivo Bioavailability , 1995, Pharmaceutical Research.

[39]  Madalena Dionísio,et al.  Amorphous Ibuprofen Confined in Nanostructured Silica Materials: A Dynamical Approach , 2011 .

[40]  H. Santos,et al.  Comparison of mesoporous silicon and non-ordered mesoporous silica materials as drug carriers for itraconazole. , 2011, International journal of pharmaceutics.

[41]  S. Qi,et al.  An investigation into the mechanism of dissolution rate enhancement of poorly water-soluble drugs from spray chilled gelucire 50/13 microspheres. , 2010, Journal of pharmaceutical sciences.

[42]  Feng Qian,et al.  Drug-polymer solubility and miscibility: Stability consideration and practical challenges in amorphous solid dispersion development. , 2010, Journal of pharmaceutical sciences.

[43]  Lian Yu,et al.  Solubility of Small-Molecule Crystals in Polymers: d-Mannitol in PVP, Indomethacin in PVP/VA, and Nifedipine in PVP/VA , 2009, Pharmaceutical Research.

[44]  Pablo G. Debenedetti,et al.  Supercooled liquids and the glass transition , 2001, Nature.

[45]  Bruno C. Hancock,et al.  What is the True Solubility Advantage for Amorphous Pharmaceuticals? , 2000, Pharmaceutical Research.

[46]  L. S. Taylor,et al.  Small scale screening to determine the ability of different polymers to inhibit drug crystallization upon rapid solvent evaporation. , 2010, Molecular pharmaceutics.

[47]  M. Harris,et al.  Evaluation of the microstructure of semicrystalline solid dispersions. , 2010, Molecular pharmaceutics.

[48]  Patrick Augustijns,et al.  Increasing the oral bioavailability of the poorly water soluble drug itraconazole with ordered mesoporous silica. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[49]  Sung-Joo Hwang,et al.  Preparation and characterization of simvastatin/hydroxypropyl-beta-cyclodextrin inclusion complex using supercritical antisolvent (SAS) process. , 2007, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[50]  G. Verreck,et al.  Preparation and Characterization of Nanofibers Containing Amorphous Drug Dispersions Generated by Electrostatic Spinning , 2003, Pharmaceutical Research.

[51]  A. Healy,et al.  Amorphous Solid Dispersions of Sulfonamide/Soluplus® and Sulfonamide/PVP Prepared by Ball Milling , 2013, AAPS PharmSciTech.

[52]  M. Espina,et al.  Role of hydroxypropyl-β-cyclodextrin on freeze-dried and gamma-irradiated PLGA and PLGA–PEG diblock copolymer nanospheres for ophthalmic flurbiprofen delivery , 2012, International journal of nanomedicine.

[53]  Hsin-Yun Hsu,et al.  Effect of substrates on naproxen-polyvinylpyrrolidone solid dispersions formed via the drop printing technique. , 2013, Journal of pharmaceutical sciences.

[54]  S. Qi,et al.  Microstructure of an immiscible polymer blend and its stabilization effect on amorphous solid dispersions. , 2013, Molecular pharmaceutics.

[55]  M Ikeda,et al.  Stability of amorphous indomethacin compounded with silica. , 2001, International journal of pharmaceutics.

[56]  Thorsteinn Loftsson,et al.  Cyclodextrins as pharmaceutical solubilizers. , 2007, Advanced drug delivery reviews.

[57]  J. Rantanen,et al.  Enhanced dissolution rate and synchronized release of drugs in binary systems through formulation: Amorphous naproxen-cimetidine mixtures prepared by mechanical activation. , 2009, Journal of controlled release : official journal of the Controlled Release Society.

[58]  Thorsteinn Loftsson,et al.  Cyclodextrins as functional excipients: methods to enhance complexation efficiency. , 2012, Journal of pharmaceutical sciences.

[59]  M. Brewster,et al.  Pharmaceutical applications of cyclodextrins: effects on drug permeation through biological membranes , 2011, The Journal of pharmacy and pharmacology.

[60]  Sejal Shah,et al.  Melt extrusion with poorly soluble drugs. , 2013, International journal of pharmaceutics.

[61]  Karthik Nagapudi,et al.  Manufacture and performance evaluation of a stable amorphous complex of an acidic drug molecule and Neusilin. , 2011, Journal of pharmaceutical sciences.

[62]  Niklas Sandler,et al.  Printing technologies in fabrication of drug delivery systems , 2013, Expert opinion on drug delivery.

[63]  F. Vogt,et al.  A Solid-State NMR Study of Amorphous Ezetimibe Dispersions in Mesoporous Silica , 2013, Pharmaceutical Research.

[64]  V. Caron,et al.  A comparison of spray drying and milling in the production of amorphous dispersions of sulfathiazole/polyvinylpyrrolidone and sulfadimidine/polyvinylpyrrolidone. , 2011, Molecular pharmaceutics.

[65]  Hsin-Yun Hsu,et al.  Crystallization and dissolution behavior of naproxen/polyethylene glycol solid dispersions. , 2013, The journal of physical chemistry. B.

[66]  Andrea Gazzaniga,et al.  Injection Molding and its application to drug delivery. , 2012, Journal of controlled release : official journal of the Controlled Release Society.

[67]  Peter Kleinebudde,et al.  Application of mixtures of polymeric carriers for dissolution enhancement of fenofibrate using hot-melt extrusion. , 2012, International journal of pharmaceutics.

[68]  Patrick Augustijns,et al.  Enhanced release of itraconazole from ordered mesoporous SBA-15 silica materials. , 2007, Chemical communications.

[69]  S. Ohtake,et al.  Effect of water on the chemical stability of amorphous pharmaceuticals: I. Small molecules. , 2013, Journal of pharmaceutical sciences.

[70]  C. Roberts,et al.  Characterization of ternary solid dispersions of itraconazole, PEG 6000, and HPMC 2910 E5. , 2008, Journal of pharmaceutical sciences.

[71]  Amrit Paudel,et al.  Manufacturing of solid dispersions of poorly water soluble drugs by spray drying: formulation and process considerations. , 2013, International journal of pharmaceutics.

[72]  Ashwini Nangia,et al.  Solubility Advantage of Amorphous Drugs and Pharmaceutical Cocrystals , 2011 .

[73]  G. Verreck,et al.  Supersaturating drug delivery systems: effect of hydrophilic cyclodextrins and other excipients on the formation and stabilization of supersaturated drug solutions. , 2008, Die Pharmazie.

[74]  Ping I. Lee,et al.  Evolution of supersaturation of amorphous pharmaceuticals: the effect of rate of supersaturation generation. , 2013, Molecular pharmaceutics.

[75]  M. Khan,et al.  Self-emulsifying drug delivery systems (SEDDS) of coenzyme Q10: formulation development and bioavailability assessment. , 2001, International journal of pharmaceutics.

[76]  S. Majumdar,et al.  Klucel™ EF and ELF polymers for immediate-release oral dosage forms prepared by melt extrusion technology , 2012, AAPS PharmSciTech.

[77]  J. Moffat,et al.  Early stage phase separation in pharmaceutical solid dispersion thin films under high humidity: improved spatial understanding using probe-based thermal and spectroscopic nanocharacterization methods. , 2013, Molecular pharmaceutics.

[78]  V. Caron,et al.  Transformation of pharmaceutical compounds upon milling and comilling: the role of T(g). , 2007, Journal of pharmaceutical sciences.

[79]  Li-Min Wang,et al.  An electrospray technique for hyperquenched glass calorimetry studies: Propylene glycol and di-n-butyl phthalate , 2007 .

[80]  Sheng Qi,et al.  Characterisation and Prediction of Phase Separation in Hot-Melt Extruded Solid Dispersions: A Thermal, Microscopic and NMR Relaxometry Study , 2010, Pharmaceutical Research.

[81]  Fredrickson,et al.  Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores , 1998, Science.

[82]  Yun Hu,et al.  Mechanochemical Reaction of Sulfathiazole with Carboxylic Acids: Formation of a Cocrystal, a Salt, and Coamorphous Solids , 2014 .

[83]  Jan Van Humbeeck,et al.  Influence of Preparation Methods on Solid State Supersaturation of Amorphous Solid Dispersions: A Case Study with Itraconazole and Eudragit E100 , 2010, Pharmaceutical Research.

[84]  T. Konno,et al.  Physical and chemical changes of medicinals in mixtures with adsorbents in the solid state. I. Effect of vapor pressure of the medicinals on changes in crystalline properties. , 1986, Chemical & pharmaceutical bulletin.

[85]  M D Ediger,et al.  Spatially heterogeneous dynamics in supercooled liquids. , 2003, Annual review of physical chemistry.

[86]  L. Carpentier,et al.  Solid-state vitrification of crystalline griseofulvin by mechanical milling. , 2012, Journal of pharmaceutical sciences.

[87]  H. Santos,et al.  Physicochemical stability of high indomethacin payload ordered mesoporous silica MCM-41 and SBA-15 microparticles. , 2011, International journal of pharmaceutics.

[88]  K. Grzybowska,et al.  Molecular dynamics, physical stability and solubility advantage from amorphous indapamide drug. , 2013, Molecular pharmaceutics.

[89]  Vesa-Pekka Lehto,et al.  Predicting the formation and stability of amorphous small molecule binary mixtures from computationally determined Flory-Huggins interaction parameter and phase diagram. , 2010, Molecular pharmaceutics.

[90]  H. Gotoh,et al.  Physicochemical properties of amorphous precipitates of cimetidine-indomethacin binary system. , 2000, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[91]  Colin E. Rowlings,et al.  Formulation studies of a poorly water-soluble drug in solid dispersions to improve bioavailability , 1995 .

[92]  Charles E. Martin,et al.  Pharmaceutical Applications of Hot-Melt Extrusion: Part I , 2007, Drug development and industrial pharmacy.

[93]  R. Tan,et al.  Dissolution enhancement of indomethacin via amorphization using co-milling and supercritical co-precipitation processing , 2013 .

[94]  Michael Lee Branham,et al.  Preparation and solid-state characterization of ball milled saquinavir mesylate for solubility enhancement. , 2012, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[95]  S. Bates,et al.  Analysis of Amorphous and Nanocrystalline Solids from Their X-Ray Diffraction Patterns , 2006, Pharmaceutical Research.

[96]  P York,et al.  Comminution of ibuprofen to produce nano-particles for rapid dissolution. , 2011, International journal of pharmaceutics.

[97]  Michael J Pikal,et al.  Effect of sorbitol and residual moisture on the stability of lyophilized antibodies: Implications for the mechanism of protein stabilization in the solid state. , 2005, Journal of pharmaceutical sciences.

[98]  C. Strachan,et al.  Coamorphous drug systems: enhanced physical stability and dissolution rate of indomethacin and naproxen. , 2011, Molecular pharmaceutics.

[99]  Rainer H Müller,et al.  Nanocrystal technology, drug delivery and clinical applications , 2008, International journal of nanomedicine.

[100]  Niklas Sandler,et al.  Tailoring controlled-release oral dosage forms by combining inkjet and flexographic printing techniques. , 2012, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[101]  Jennifer B Dressman,et al.  Dissolution enhancement of fenofibrate by micronization, cogrinding and spray-drying: comparison with commercial preparations. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[102]  T. Rades,et al.  Physical characterization and stability of amorphous indomethacin and ranitidine hydrochloride binary systems prepared by mechanical activation. , 2009, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[103]  H. Gotoh,et al.  Physicochemical properties of amorphous salt of cimetidine and diflunisal system. , 2002, International journal of pharmaceutics.

[104]  S. Riegelman,et al.  Pharmaceutical applications of solid dispersion systems. , 1971, Journal of pharmaceutical sciences.

[105]  A. Serajuddin,et al.  Solid dispersion of poorly water-soluble drugs: early promises, subsequent problems, and recent breakthroughs. , 1999, Journal of pharmaceutical sciences.

[106]  Deepak Bahl,et al.  Amorphization of Indomethacin by Co-Grinding with Neusilin US2: Amorphization Kinetics, Physical Stability and Mechanism , 2006, Pharmaceutical Research.

[107]  J. B. Higgins,et al.  A new family of mesoporous molecular sieves prepared with liquid crystal templates , 1992 .

[108]  J. Moffat,et al.  Spatial Characterization of Hot Melt Extruded Dispersion Systems Using Thermal Atomic Force Microscopy Methods: The Effects of Processing Parameters on Phase Separation , 2014, Pharmaceutical Research.

[109]  Thomas Rades,et al.  Emerging trends in the stabilization of amorphous drugs. , 2013, International journal of pharmaceutics.

[110]  Qinfu Zhao,et al.  Ordered nanoporous silica as carriers for improved delivery of water insoluble drugs: a comparative study between three dimensional and two dimensional macroporous silica , 2013, International journal of nanomedicine.

[111]  G. Zografi,et al.  Effects of Lyophilization on the Physical Characteristics and Chemical Stability of Amorphous Quinapril Hydrochloride , 2000, Pharmaceutical Research.

[112]  F. Hirayama,et al.  Inhibitory Effect of 2‐Hydroxypropyl‐β‐cyclodextrin on Crystal‐growth of Nifedipine During Storage: Superior Dissolution and Oral Bioavailability Compared with Polyvinylpyrrolidone K‐30 , 1992, The Journal of pharmacy and pharmacology.

[113]  Elaine Merisko-Liversidge,et al.  Nanosizing for oral and parenteral drug delivery: a perspective on formulating poorly-water soluble compounds using wet media milling technology. , 2011, Advanced drug delivery reviews.

[114]  Sheng Qi,et al.  Physicochemical properties of the amorphous drug, cast films, and spray dried powders to predict formulation probability of success for solid dispersions: etravirine. , 2011, Journal of pharmaceutical sciences.

[115]  C. Prestidge,et al.  Silica materials in drug delivery applications. , 2011, Current drug discovery technologies.

[116]  J. Mitchell,et al.  Dissolution enhancement of poorly water-soluble APIs processed by hot-melt extrusion using hydrophilic polymers , 2013, Drug development and industrial pharmacy.

[117]  C. Jackson,et al.  Vitrification and Crystallization of Organic Liquids Confined to Nanoscale Pores , 1996 .

[118]  Bruno C. Hancock,et al.  Molecular Mobility of Amorphous Pharmaceutical Solids Below Their Glass Transition Temperatures , 1995, Pharmaceutical Research.

[119]  J. Martens,et al.  Potential of ordered mesoporous silica for oral delivery of poorly soluble drugs. , 2011, Therapeutic delivery.

[120]  Duk Soon Choi,et al.  Evaluation of solid state properties of solid dispersions prepared by hot-melt extrusion and solvent co-precipitation. , 2008, International journal of pharmaceutics.

[121]  P. Belton,et al.  An investigation into the crystallisation behaviour of an amorphous cryomilled pharmaceutical material above and below the glass transition temperature. , 2010, Journal of pharmaceutical sciences.

[122]  Niels Bent Larsen,et al.  Studies of spin-coated polymer films , 2005 .

[123]  Lynne S. Taylor,et al.  Ability of Different Polymers to Inhibit the Crystallization of Amorphous Felodipine in the Presence of Moisture , 2008, Pharmaceutical Research.

[124]  M. Lawrence,et al.  Effect of drug-polymer interactions on the aqueous solubility of milled solid dispersions. , 2013, International journal of pharmaceutics.

[125]  L Yu,et al.  Amorphous pharmaceutical solids: preparation, characterization and stabilization. , 2001, Advanced drug delivery reviews.

[126]  Jin Kim,et al.  Physicochemical characterization of solid dispersion of furosemide with TPGS. , 2003, International journal of pharmaceutics.

[127]  P York,et al.  Crystal engineering of active pharmaceutical ingredients to improve solubility and dissolution rates. , 2007, Advanced drug delivery reviews.

[128]  N. Rodríguez-Hornedo,et al.  Crystallization pathways and kinetics of carbamazepine-nicotinamide cocrystals from the amorphous state by in situ thermomicroscopy, spectroscopy, and calorimetry studies. , 2007, Journal of pharmaceutical sciences.

[129]  George Zografi,et al.  Assessing the performance of amorphous solid dispersions. , 2012, Journal of pharmaceutical sciences.

[130]  R. Bogner,et al.  Application of mesoporous silicon dioxide and silicate in oral amorphous drug delivery systems. , 2012, Journal of pharmaceutical sciences.

[131]  Cheng-Hung Hsu,et al.  Solid-state transformation of different gabapentin polymorphs upon milling and co-milling. , 2010, International journal of pharmaceutics.

[132]  K. Peh,et al.  Effect of HPMC concentration on β-cyclodextrin solubilization of norfloxacin. , 2014, Carbohydrate polymers.

[133]  He Hui,et al.  Oxidized mesoporous silicon microparticles for improved oral delivery of poorly soluble drugs. , 2010, Molecular pharmaceutics.

[134]  Jérôme Mantanus,et al.  PAT tools for the control of co-extrusion implants manufacturing process. , 2013, International journal of pharmaceutics.

[135]  J. Humbeeck,et al.  Evaluation of the formulation of solid dispersions by co-spray drying itraconazole with Inutec SP1, a polymeric surfactant, in combination with PVPVA 64. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[136]  R. Bogner,et al.  Spontaneous crystalline-to-amorphous phase transformation of organic or medicinal compounds in the presence of porous media, part 1: thermodynamics of spontaneous amorphization. , 2011, Journal of pharmaceutical sciences.

[137]  Christel A.S. Bergström,et al.  Early drug development predictions of glass-forming ability and physical stability of drugs. , 2013, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[138]  J. Rantanen,et al.  Investigations on the effect of different cooling rates on the stability of amorphous indomethacin. , 2011, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[139]  Patrick J. Marsac,et al.  Theoretical and Practical Approaches for Prediction of Drug–Polymer Miscibility and Solubility , 2006, Pharmaceutical Research.

[140]  Keiji. Yamamoto,et al.  Dissolution improvement of RS-8359 by the solid dispersion prepared by the solvent method , 1998 .

[141]  J. Devoisselle,et al.  Inclusion of ibuprofen in mesoporous templated silica: drug loading and release property. , 2004, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[142]  Paul F. McMillan,et al.  Relaxation in glassforming liquids and amorphous solids , 2000 .

[143]  C. Angell Relaxation in liquids, polymers and plastic crystals — strong/fragile patterns and problems☆ , 1991 .

[144]  T. Azaïs,et al.  Solution State NMR Techniques Applied to Solid State Samples: Characterization of Benzoic Acid Confined in MCM-41 , 2010 .

[145]  Yasuhiro Sakamoto,et al.  Direct imaging of the pores and cages of three-dimensional mesoporous materials , 2000, Nature.

[146]  A. Saha,et al.  Formation of physically stable amorphous phase of ibuprofen by solid state milling with kaolin. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[147]  Huibi Xu,et al.  A new solid self-microemulsifying formulation prepared by spray-drying to improve the oral bioavailability of poorly water soluble drugs. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[148]  C Vervaet,et al.  Near infrared and Raman spectroscopy for the in-process monitoring of pharmaceutical production processes. , 2011, International journal of pharmaceutics.

[149]  T. De Beer,et al.  Raman spectroscopy for the in-line polymer-drug quantification and solid state characterization during a pharmaceutical hot-melt extrusion process. , 2011, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[150]  Joel Rosenblatt,et al.  Incorporation of drugs in an amorphous state into electrospun nanofibers composed of a water-insoluble, nonbiodegradable polymer. , 2003, Journal of controlled release : official journal of the Controlled Release Society.

[151]  K. Terada,et al.  Stability of amorphous drug, 2-benzyl-5-(4-chlorophenyl)-6-[4-(methylthio)phenyl]-2H-pyridazin-3-one, in silica mesopores and measurement of its molecular mobility by solid-state (13)C NMR spectroscopy. , 2011, International journal of pharmaceutics.

[152]  Patrick J. Marsac,et al.  Estimation of Drug–Polymer Miscibility and Solubility in Amorphous Solid Dispersions Using Experimentally Determined Interaction Parameters , 2008, Pharmaceutical Research.

[153]  Chandan Bhugra,et al.  Role of thermodynamic, molecular, and kinetic factors in crystallization from the amorphous state. , 2008, Journal of pharmaceutical sciences.

[154]  J. Dressman,et al.  In vitro tools for evaluating novel dosage forms of poorly soluble, weakly basic drugs: case example ketoconazole. , 2013, Journal of pharmaceutical sciences.

[155]  Bruno C. Hancock,et al.  Interpretation of relaxation time constants for amorphous pharmaceutical systems. , 2000, Journal of pharmaceutical sciences.

[156]  K. Leong,et al.  Electrohydrodynamics: A facile technique to fabricate drug delivery systems. , 2009, Advanced drug delivery reviews.

[157]  O. Corrigan Mechanisms of Dissolution of Fast Release Solid Dispersions , 1985 .

[158]  S. Onoue,et al.  Novel crystalline solid dispersion of tranilast with high photostability and improved oral bioavailability. , 2010, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[159]  Michael T Harris,et al.  Modification of crystallization behavior in drug/polyethylene glycol solid dispersions. , 2012, Molecular pharmaceutics.

[160]  S. Riegelman,et al.  Preparation and dissolution characteristics of several fast-release solid dispersions of griseofulvin. , 1969, Journal of pharmaceutical sciences.

[161]  P. Belton,et al.  Characterisation of solid dispersions of paracetamol and EUDRAGIT E prepared by hot-melt extrusion using thermal, microthermal and spectroscopic analysis. , 2008, International journal of pharmaceutics.

[162]  John Baldoni,et al.  Electrospun Nanofibers in Oral Drug Delivery , 2010, Pharmaceutical Research.

[163]  Patrick Augustijns,et al.  Combined use of ordered mesoporous silica and precipitation inhibitors for improved oral absorption of the poorly soluble weak base itraconazole. , 2010, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[164]  L. Naesens,et al.  Physicochemical characterization of solid dispersions of the antiviral agent UC-781 with polyethylene glycol 6000 and Gelucire 44/14. , 2000, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[165]  Deliang Zhou,et al.  Thermodynamics, molecular mobility and crystallization kinetics of amorphous griseofulvin. , 2008, Molecular pharmaceutics.

[166]  Jianxiang Zhang,et al.  Cyclodextrin-based supramolecular systems for drug delivery: recent progress and future perspective. , 2013, Advanced drug delivery reviews.

[167]  B. Wunderlich A classification of molecules, phases, and transitions as recognized by thermal analysis , 1999 .

[168]  V. Lehto,et al.  Mesoporous systems for poorly soluble drugs. , 2013, International journal of pharmaceutics.

[169]  T. De Beer,et al.  In-line NIR spectroscopy for the understanding of polymer-drug interaction during pharmaceutical hot-melt extrusion. , 2012, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[170]  G. Alderborn,et al.  Moisture-induced surface crystallization of spray-dried amorphous lactose particles studied by atomic force microscopy. , 2004, Journal of pharmaceutical sciences.

[171]  C. Strachan,et al.  Co-amorphous simvastatin and glipizide combinations show improved physical stability without evidence of intermolecular interactions. , 2012, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[172]  W. Ali,et al.  Stochiometrically governed molecular interactions in drug: poloxamer solid dispersions. , 2010, International journal of pharmaceutics.

[173]  R. Suryanarayanan,et al.  Local mobility in amorphous pharmaceuticals--characterization and implications on stability. , 2009, Journal of pharmaceutical sciences.

[174]  Charles E. Martin,et al.  Pharmaceutical Applications of Hot-Melt Extrusion: Part II , 2007, Drug development and industrial pharmacy.

[175]  Thomas Rades,et al.  Correlating thermodynamic and kinetic parameters with amorphous stability. , 2009, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[176]  G. Zografi,et al.  Phase Behavior of Binary and Ternary Amorphous Mixtures Containing Indomethacin, Citric Acid, and PVP , 1998, Pharmaceutical Research.

[177]  M. Descamps,et al.  Solid State Amorphization of Pharmaceuticals , 2009 .

[178]  M. Descamps,et al.  Low- and high-frequency Raman investigations on caffeine: polymorphism, disorder and phase transformation. , 2011, The journal of physical chemistry. B.

[179]  Bernard Van Eerdenbrugh,et al.  A classification system to assess the crystallization tendency of organic molecules from undercooled melts. , 2010, Journal of pharmaceutical sciences.

[180]  S. Qi,et al.  Stabilisation of amorphous drugs under high humidity using pharmaceutical thin films. , 2013, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[181]  Simon Bates,et al.  Evaluation of Drug-Polymer Miscibility in Amorphous Solid Dispersion Systems , 2009, Pharmaceutical Research.

[182]  R. Suryanarayanan,et al.  Correlation between molecular mobility and physical stability of amorphous itraconazole. , 2013, Molecular pharmaceutics.

[183]  Bernard Van Eerdenbrugh,et al.  Crystallization tendency of active pharmaceutical ingredients following rapid solvent evaporation--classification and comparison with crystallization tendency from undercooled melts. , 2010, Journal of pharmaceutical sciences.

[184]  T. Rades,et al.  Formation and physical stability of the amorphous phase of ranitidine hydrochloride polymorphs prepared by cryo-milling. , 2008, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[185]  R. Tan,et al.  Physical state and dissolution of ibuprofen formulated by co-spray drying with mesoporous silica: effect of pore and particle size. , 2011, International journal of pharmaceutics.

[186]  M. Descamps,et al.  A new protocol to determine the solubility of drugs into polymer matrixes. , 2013, Molecular pharmaceutics.

[187]  B. Sarmento,et al.  Solid dispersions as strategy to improve oral bioavailability of poor water soluble drugs. , 2007, Drug discovery today.

[188]  T. Rades,et al.  Factors affecting incorporation of drug into solid solution with HPMCP during solvent change co-precipitation. , 2002, International journal of pharmaceutics.

[189]  C. Jackson,et al.  The melting behavior of organic materials confined in porous solids , 1990 .

[190]  Shigeo Kojima,et al.  Molecular mobility-based estimation of the crystallization rates of amorphous nifedipine and phenobarbital in poly(vinylpyrrolidone) solid dispersions. , 2004, Journal of pharmaceutical sciences.

[191]  K. Motoyama,et al.  Recent Findings on Safety Profiles of Cyclodextrins, Cyclodextrin Conjugates, and Polypseudorotaxanes , 2011 .

[192]  Shun-Ji Jin,et al.  Physicochemical properties and oral bioavailability of amorphous atorvastatin hemi-calcium using spray-drying and SAS process. , 2008, International journal of pharmaceutics.