THE USE OF LOW-FREQUENCY DIELECTRIC-SPECTROSCOPY AS A NOVEL MEANS OF INVESTIGATING THE STRUCTURE OF PHARMACEUTICAL GLYCERIDE BASES

The dielectric responses of five glyceride bases have been assessed us ing low frequency dielectric spectroscopy. It was observed that each b ase showed different electrical behaviour. In addition, samples were e ither slow or fast cooled from the melt in order to change the physica l structure of each material; in all cases where differences were obse rved, the slow cooled samples showed a greater response than fast cool ed materials. The results are discussed in terms of both the movement of charges within the system and the relationship between these charge movements and the physical structure of the material. It is proposed that the differences in dielectric response between the various sample s may be influenced by a number of factors, particularly chemical comp osition, while the differences between the responses of fast and slow cooled materials may be a reflection of segregation of the components of the bases into distinct regions. These studies indicate that dielec tric analysis may be used as a novel means of characterising solid mat erials of pharmaceutical interest.