Numerical modeling of the dissolution of drug nanocrystals and its application to industrial product development.

The apparent solubility of drug nanocrystals in equilibrium was experimentally determined for a drug-stabilizer system with different particle size distributions. True supersaturation was identified for ultrafine drug nanocrystals with an almost 2-fold increase compared to the thermodynamic solubility of related coarse drug crystals, highlighting their enabling potential to enhance bioavailability. The experimental results were applied to investigate the associated dissolution behavior in a closed system by numerical modeling according to the Ostwald-Freundlich and Noyes-Whitney / Nernst-Brunner equations.

MDSC parameter optimization for the determination of glass transitions using a design of experiments approach.

Optimum experimental parameters for modulated differential scanning calorimetry were determined using a design of experiments approach. Two different strategies were tested, an isothermal method only varying modulation period and amplitude and a non-isothermal method including an underlying linear heating ramp. Three different test compounds were investigated including a blank of NaCl, a small pharmaceutically active molecule (Valsartan) and a polymer (PVP-VA 64).