Table II.

Characterization Methods for Lipid Excipients

Method	Information	Application in development
DSC (also coupled with XRD or TGA)	Melting and recrystallization point/range, peak broadness, polymorphism, thermal behavior, melting/recrystallizing fractions, chemical stability	Selection of process temperatures, prediction of storage stability and process performance (agglomeration/ film formation)
Isothermal microcalorimetry	Monitoring of thermal events	Detection of polymorphic changes during storage
XRD	Crystallinity, morphology, polymorphism	Prediction of storage stability
Hot stage polarization microscopy (HSM)	Crystal growth under well-defined conditions, polymorphic transformation	Selection of cooling rate, coating quality, prediction of storage stability
FT-IR/ NIR/ Raman	Polymorphism (finger print), chemical composition	Product quality, process monitoring (PAT)
Goniometry contact angle	Wettability, surface tension	Solubility, dissolution rate
Rheometer	Melt viscosity (shear rate, temperature), thermoplastic behavior of excipients	Processability (spraying techniques), selection of process parameters
Texture analyzer	Brittleness, film adhesion, swelling behavior, conductivity,	Coating quality, stability
Dilatometry	Thermal expansion/contraction	Coating quality
Profilometry	Surface roughness, topographic analysis	Mouth feel
Penetrometry	Material strength, hardness	Mouth feel
Dynamic vapor sorption (DVS)	Water sorption/desorption	Moisture protection
Karl Fischer titrimetry	Water content	Moisture protection
Acid/Base titration	Saponification value Acid value	Calculation of HLB (186)
TD-NMR	Solid fat content (SFC)	Spreadability, firmness, mouth feel, processability and stability