Differential Scanning Calorimetry (DSC)

Differential Scanning Calorimetry (DSC) constitutes a thermoanalytical technique measuring heat flow differences between sample and reference materials as temperature changes under controlled conditions, providing information about thermal transitions including melting, crystallisation, glass transitions, and protein unfolding. This powerful characterisation method determines transition temperatures, enthalpy changes, and thermal stability profiles essential for understanding material properties and developing stable pharmaceutical formulations. DSC applications span small molecules analysing polymorphic forms and purity to biologics assessing conformational stability and formulation effects on protein structure.

The pharmaceutical industry employs DSC throughout development for diverse characterisation needs. Small molecule development uses DSC identifying polymorphs with distinct melting points affecting bioavailability and patent protection, assessing amorphous content in formulations, and evaluating drug-excipient compatibility. Biologic development applies DSC measuring protein melting temperatures reflecting conformational stability, comparing biosimilar thermal profiles to reference products, and evaluating formulation effects on thermal stability guiding excipient selection. Quality control employs DSC verifying material identity, detecting polymorphic changes during storage, and confirming batch-to-batch consistency. Advanced DSC variants include modulated DSC separating overlapping transitions, high-sensitivity DSC for dilute proteins, and differential scanning fluorimetry using fluorescent dyes monitoring protein unfolding. As formulation complexity increases with amorphous dispersions, co-crystals, and complex biologics, DSC remains foundational characterisation technique providing critical thermal property information.