Technique

What Property Does It Measure?

What Is The Information Used For?

Physicochemical Properties

Inverse Gas Chromatography (iGC)

Surface energy

• Determination of surface interactions within formulations
• Studying effects of processing techniques e.g. blending, milling
• Assessing manufacturability, processability, aging, dissolution kinetics
• Studying drug-carrier interactions
• Optimization of formulation design

Dynamic Vapor Sorption (DVS)

Solvent interaction, hygroscopicity

• Formulation and packaging design
• Determining manufacture conditions
• Determining storage and transportation conditions
• Studying stoichiometry

Fourier Transform Infrared (FT-IR) Spectroscopy

 Chemical structure and identity

• Material identity confirmation
• Molecular structure and functional group determination
• Drug-excipient interaction determination
• Identification of impurities or contamination

Others

Viscosity, pH, Karl Fisher

Flowability, homogeneity, stability, solubility, dissolution rate, moisture content

Size & Shape

Light Microscopy

Particle size, shape and morphology

• Choosing optimal parameters for other techniques, e.g. laser diffraction
• Identifying particle behavior (e.g. agglomeration), and defects (e.g. contamination)
• Determining birefringence, crystallinity

Scanning Electron Microscopy (SEM)

Particle size, shape, morphology, behavior and interactions

• Nano- and micro-scale size and shape assessment
• Visualization of agglomeration and defects
• Identification of interactions between drug substance and excipients
• Choosing optimal parameters for other techniques, e.g. laser diffraction
• Studying the distribution of elements within drug particles (when combined with Energy Dispersive X-ray (EDX) spectroscopy)
• Identification of defects e.g. contamination

Laser Diffraction

Particle size distribution (PSD)

• Studying the effects of processing e.g. milling
• Developing new materials and products with desired PSD for optimal bioavailability, dissolution, absorption
• Optimizing manufacturing process

Dynamic Image Analysis (QICPIC)

Particle size and shape

• Better description of size and shape of non-spherical particles
• Identification of unusual particles, e.g. contamination, fibers
• Ensuring quality and batch consistency

Light Obscuration (HIAC)

Particle size

• Performing visible and sub-visible particulate matter testing

Surface

Gas Adsorption Analysis

Specific surface area and porosity

• Understanding dissolution rate, processing, useful shelf-life and bioavailability
• Stability of the API / excipient
• Selection of appropriate formulation and processing methods
• Optimization of drug release rate and targeting

Density

Gas pycnometry

True density and volume

• Ensuring quality and consistency of materials
• Supporting other characterization such as gas adsorption and modelling

Bulk & Tap Density

Density, packing properties

• Determine flowability, compressibility, compactability
• Determine packing and filling properties of materials

Solid Form Characterization

Powder X-ray Diffraction (PXRD)

Crystallinity, crystal structure, polymorphism, amorphous content, purity, phase identity

• Phase identification and purity
• Quantitative phase analysis
• Polymorphism screening and identification of optimal crystalline form
• Determination of crystallinity and amorphous content
• Determination of batch consistency
• Identification of contaminants
• Amorphous characterization

Differential Scanning Calorimetry (DSC)

Solvates, Hydrates, Glass Transition, Melting Point, Thermal Stability

• Determining compatibility and interactions between formulation components
• Assessing purity
• Amorphous content determination
• Glass transition point determination
• Support polymorph screening

Thermogravimetric Analysis (TGA)

Thermal stability, volatiles content (e.g. moisture, solvent), purity

• Determining hydration / solvation levels
• Determining degradation pathways
• Developing and optimizing manufacturing processes
• Designing packaging and storage conditions

Hot Stage Microscopy

Melting/boiling point, thermal stability, desolvation, phase transitions, miscibility

• Supporting formulation development
• Visualizing crystallization process, desolvation, polymorphism, phase transitions, melting/boiling points, glass transitions
• Troubleshooting problems
• Supplementing DSC and TGA data
• Supporting thermal analysis method development
• Cocrystal screening

Fourier Transform Infrared (FT-IR) Spectroscopy

Chemical structure and identity

• Material identity confirmation
• Molecular structure and functional group determination
• Drug-excipient interaction determination
• Identification of impurities and contamination