| Carbamazepine (CBZ) shows a poor dissolution, therefore, it is important to enhance its
dissolution in GI tract to improve its bioavailability. In the present study, a new hydrophilic
carrier, D-gluconolactone (GNL), was extruded with CBZ at various molar ratios to produce
granules by using hot melt extrusion (HME) processing. The granular extrudates were
characterised by X-ray powder diffraction, differential scanning calorimetry and hot stage
microscopy to determine the solid state of CBZ. It was found that bulk CBZ (Form-III)
transformed to the polymorphic Form-I during the HME processing. GNL was proved to be an
efficient carrier for CBZ to enhance the dissolution rate. The increase in the dissolution rate was
observed for both physical mixtures and the extrudates of CBZ-GNL. However, the extrudates
showed faster dissolution rates compared to physical mixtures in an ascending order of
2:1 5 1:1 5 1.5:1 (CBZ:GNL). The increase in the dissolution rates was attributed to the
transformation of CBZ III to Form-I and also to the increased drug wettability/solubilisation in
the presence of the carrier. |