ReviewsAnalytical techniques for quantification of amorphous/crystalline phases in pharmaceutical solids
Section snippets
INTRODUCTION
Once being an exclusive domain of ceramic and polymer science,1 glassy state is now extensively studied in diverse fields like basic physics, electronics, metallurgy, space research, food sciences,2 and pharmaceutical sciences.3,4 Vitrification or glass formation is the manner in which nature affords protection to organisms against harsh climatic conditions,5 the strategy mankind uses to preserve food stuffs,6 the means by which highly pure semiconductors and optics are prepared,7 and also the
NEED FOR QUANTIFICATION OF AMORPHOUS PHASE
The amorphous state can arise in three sets of circumstances: (i) the drug or excipient may be deliberately produced in an amorphous form to enhance product performance. The use of plasticizers, including water to lower the Tg of various cellulosic and acrylic polymers utilized in film coating and the use of spray-dried lactose and microcrystalline cellulose as direct compression excipients is an apt example of this.18 Other important examples of this strategy include the preparation of glassy
QUANTIFICATION TECHNIQUES
Over the years, various analytical techniques have been reported for quantifying amorphous or crystalline phase in solids. These techniques vary in their working principles, mechanical and thermal stress that is applied to the sample, time of analysis and amount of sample required, sensitivity of the technique to minute changes, and the necessity of internal or external standards.25 Numerous considerations are involved in the development of a good analytical method like sensitivity,
CONCLUSIONS
Over the past two decades, the increased usage of amorphous drugs as an approach to enhance solubility, coupled with the development of amorphous excipients for improved performance of dosage forms, has necessitated the development of efficient methods for characterization and quantification of the amorphous content. There are many precise and accurate methods suitable for characterizing amorphous pharmaceutical materials in all their configurations, including final dosage forms. As with any
REFERENCES (143)
Characterization of habits and crystalline modifications of solids and their pharmaceutical applications
J Pharm Sci
(1975)Amorphous pharmaceutical solids: Preparation, characterization and stabilization
Adv Drug Del Rev
(2001)- et al.
Characteristics and significance of the amorphous state in pharmaceutical systems
J Pharm Sci
(1997) - et al.
Assessment of disorder in crystalline solids
Int J Pharm
(1994) - et al.
Studies on the crystallinity of a pharmaceutical development drug substance
J Pharm Sci
(2005) - et al.
The relevance of the amorphous state to pharmaceutical dosage forms: Glassy drugs and freeze dried systems
Int J Pharm
(1999) - et al.
Some pharmaceutical properties of novobiocin
J Am Pharm Assoc Sci Ed
(1960) - et al.
Crystallization of indomethacin from the amorphous state below and above its glass transition temperature
J Pharm Sci
(1994) - et al.
Application of diffuse reflectance near-infrared spectroscopy for the determination of crystallinity
J Pharm Sci
(2000) Characterization of calcium fenoprofen 1. Powder dissolution rate and degree of crystallinity
Int J Pharm
(1990)
A disruption index for quantifying the solid state disorder induced by additives or impurities. I. Definition and evaluation from heat of fusion
Int J Pharm
Entropy of processing: A new quantity for comparing solid-state disorder of pharmaceutical materials
Int J Pharm
Assessment of disorder in crystalline powders—A review of analytical techniques and their application
Int J Pharm
Characterization of the solid state: Quantitative issues
Adv Drug Del Rev
Hydration and dehydration of crystalline and amorphous forms of raffinose
J Pharm Sci
Assessment of the degree of disorder in the crystalline solids by isothermal microcalorimetry
Int J Pharm
The effect of water to ethanol feed ratio on physical properties and aerosolization behavior of spray dried cromolyn sodium particles
J Pharm Sci
Determination of the changes in surface energetics of cefditoren pivoxil as a consequence of processing induced disorder and equilibration to different relative humidities
Int J Pharm
Evaluation of solubility parameter to predict apparent solubility of amorphous and crystalline cefditoren pivoxil
Pharm Acta Helv
Quantification of crystallinity in blends of lyophilized and crystalline MK-0591using X-ray powder diffraction
Int J Pharm
Comparison of the crystallinity of imipenem samples by X-ray diffraction of amorphous material
J Pharm Sci
Quantifying amorphous content of lactose using parallel beam X-ray powder diffraction and whole pattern fitting
J Pharm Biomed Anal
Use of solution calorimetry to determine the extent of crystallinity of drugs and excipients
Int J Pharm
The potential of high speed DSC (Hyper-DSC) for the detection and quantification of small amounts of amorphous content in predominantly crystalline samples
Int J Pharm
Quantification of low levels of amorphous content in maltitol
Thermochim Acta
Optimisation of powders for pulmonary delivery using supercritical fluid technology
Eur J Pharm Sci
An approach to estimate the amorphous content of pharmaceutical powders using calorimetry with no calibration standards
Int J Pharm
Solid state NMR and DSC methods for quantifying the amorphous content in solid dosage forms: An application to ball-milling of trehalose
Int J Pharm
The use of MTDSC to assess the amorphous phase content of a micronised drug substance
Int J Pharm
Conditions required for heat-capacity measurements using modulated-temperature calorimetry
Int J Pharm
The use of isothermal microcalorimetry in the study of changes in crystallinity induced during the processing of powders
Int J Pharm
The use of thermal techniques to assess the impact of feed concentration on the amorphous content and polymorphic forms present in spray dried lactose
Int J Pharm
The use of isothermal microcalorimetry in the study of small degrees of amorphous content of powders
Int J Pharm
Quantification of amorphous content in mixed systems: Amorphous trehalose with lactose
Thermochim Acta
The use of isothermal microcalorimetry in the study of changes in crystallinity of spray-dried salbutamol sulphate
Int J Pharm
The influence of additives on the recrystallisation of amorphous spray dried lactose
Int J Pharm
Assessment of amorphous content by microcalorimetry
J Pharm Sci
The use of gravimetric studies to assess the degree of crystallinity of predominantly crystalline powders
Int J Pharm
Evaluation of heat-conduction microcalorimetry in pharmaceutical stability studies: VI. Continuous monitoring of the interaction of water vapour with powders and powder mixtures at various relative humidity
Int J Pharm
Evaluation of heat conduction microcalorimetry in pharmaceutical stability studies: V. A new approach for continuous measurements in abundant water vapour
Int J Pharm
Feasibility of using isothermal microcalorimetry to evaluate the physical stability of amorphous nifedipine and phenobarbital
Thermochim Acta
The use of isothermal microcalorimetry in the study of small degrees of amorphous content of a hydrophobic powder
Int J Pharm
Approaches to determine the enthalpy of crystallisation, and amorphous content, of lactose from isothermal calorimetric data
Int J Pharm
Water sorption/desorption- near IR and calorimetric study of crystalline and amorphous raffinose
Int J Pharm
The quantification of small degrees of disorder in lactose using solution calorimetry
Int J Pharm
A theoretical treatment of changes in energy and entropy of solids caused by additives and impurities in solid solution
Int J Pharm
Thermochemical results for "tris" as a test substance in solution calorimetry
J Chem Thermodynam
NIST and standards for calorimetry
Thermochim Acta
The dissolution of propan-1-ol and dilution of 10 wt.% propan-1-ol solution in water as calibration and test reactions in solution calorimetry
Thermochim Acta
An investigation of calibration methods for solution calorimetry
Int J Pharm
Cited by (325)
Harmonic and anharmonic studies on THz spectra of two vanillin polymorphs
2024, Spectrochimica Acta - Part A: Molecular and Biomolecular SpectroscopyComplexities related to the amorphous content of lactose carriers
2023, International Journal of Pharmaceutics: XRole of Crystal Disorder and Mechanoactivation in Solid-State Stability of Pharmaceuticals
2023, Journal of Pharmaceutical SciencesSelection of bionic Co-former improves the dissolution of Neohesperidin via Co-amorphous solid dispersion with Naringin
2022, European Journal of Pharmaceutics and BiopharmaceuticsComparison of Differential Scanning Calorimetry, Powder X-ray Diffraction, and Solid-state Nuclear Magnetic Resonance Spectroscopy for Measuring Crystallinity in Amorphous Solid Dispersions - Application to Drug-in-polymer Solubility
2022, Journal of Pharmaceutical SciencesCitation Excerpt :PXRD has been used extensively for the detection and quantitation of molecular order (i.e., crystallinity) in pharmaceutical systems.13 However, unlike DSC methods, PXRD does not require any additional sample heating and, because a full powder pattern integration was used, variations in crystal quality, particle size, or preferred orientation have less of an effect on quantitation.13 Quantitation based on the prominent crystalline peaks rather than the small amorphous component is preferable and provides the option for faster solubility analysis for high drug loadings.