Solid Dispersion Approach Improving Dissolution Rate of Stiripentol: a Novel Antiepileptic Drug

Some drugs have low bioavailability due to their poor aqueous solubility and/or slow dissolution rate in biological fluids. Stiripentol (STP) is a novel anticonvulsant drug that is structurally unrelated to the currently available antiepileptics. It has poor aqueous solubility and its solubility has to be enhanced accordingly. Polyethyleneglycol 6000 (PEG-6000) is commonly utilized as a hydrophilic carrier for poorly water soluble drugs in order to improve their bioavailability. STP and PEG-6000 binary system was obtained by physical mixture, solvent evaporation, co-evaporation and melting methods using different weight ratios. The properties of the prepared binary systems were evaluated using dissolution rate, phase solubility, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscope (SEM) studies. The FTIR spectroscopic studies showed the stability of STP and absence of STP-PEG-6000 interaction. The DSC and SEM studies indicated the amorphous state of STP in its binary systems with PEG-6000. Dissolution profile of STP was significantly improved via complexation with PEG-6000 as compared with the pure drug. The binary system which was prepared using melting method showed the highest dissolution rate. The promising results of the prepared binary systems open the avenue for further oral formulation of STP.