Characterisation of spray-dried lactose using modulated differential scanning calorimetry

Modulated differential scanning calorimetry, a recent development to differential scanning calorimetry, has been investigated as a tool for the characterisation of low moisture content spray-dried lactose. Particular attention was paid to evaluating the effect of experimental parameters, such as pan type, period of modulation, sample mass and calibration method, on the results obtained. The quality of the sine wave oscillation was assessed by plotting the modulated data in the form of a Lissajous figure. It was found that the MDSC technique could be of benefit in the investigation of the amorphous lactose sample by allowing the change in heat capacity at the glass transition to be measured separately from the associated endotherm. (C) 1998 Elsevier Science B.V.