THE USE OF LOW FREQUENCY DIELECTRIC SPECTROSCOPY AS A MEANS OF CHARACTERISING AN AMORPHOUS DRUG SUBSTANCE

摘要

The purpose of this investigation was to investigate the use of low frequency dielectric spectroscopy as a means of characterising the thermal transitions of an amorphous drug substance. The dielectric behaviour of amorphous indomethacin was investigated over a temperature range of 10 to 160℃ and a frequency range of 10~(-3) to 10~6 Hz. The glass transition, recrystallisation and melting of amorphous indomethacin are identified and the response modelled in terms of an equivalent circuit.