INCREASED SOLUBILITY AND DISSOLUTION OF GELUCIRE® 50/13 SOLID DISPERSIONS CONTAINING CARBAMAZEPINE

Carbamazepine is widely used in the treatment of psychomotor epilepsy; however, its low aqueous solubility can limit therapeutic efficacy. In this study, solid dispersions were developed via hot melt extrusion to enhance the solubility of the drug and dissolution profile. Notably, the extrusion process induced a partial polymorphic conversion of carbamazepine from forms III to I, a less stable but more soluble form, which likely contributed to the improved performance. Dispersions were prepared using Gelucire® 50/13, polyethylene glycol (PEG) 4000, PEG 6000, and a PEG 4000/6000 blend at drug-to-carrier ratios of 1:9, 1:5, and 1:1. The formulation containing Gelucire® 50/13 at a 1:9 ratio exhibited the highest solubility (approximately three times greater than that of the pure drug) and a significantly enhanced dissolution profile. Characterization by X-ray diffraction, infrared spectroscopy, hot-stage microscopy, and thermal analysis confirmed the absence of physicochemical interactions between the drug and the carriers. Among the carriers tested, Gelucire® 50/13 emerged as the most promising for improving carbamazepine solubility and dissolution, potentially enhancing therapeutic efficacy and minimizing adverse effects.