Preparation and characterization of domperidone solid dispersions

Domperidone is a highly water insoluble drug exhibiting poor dissolution pattern. The purpose of this work was to increase the dissolution rate of Domperidone by formation of solid dispersion with different water soluble carriers. Binary systems of Domperidone were prepared with polyvinyl pyrrolidone k-30 (PVP), poloxamer 188 (P188) and polyethylene glycol 6000 (PEG 6000) at different weight ratios using the solvent evaporation method, physical mixtures of the same systems were also used. The effect of the method of preparation was also investigated by preparing some selected formulations using melting method. As P188 is known to inhibit CYP3A4 enzyme which is responsible for hepatic metabolism of many drugs including Domperidone, the effect of incorporation of PVP or PEG 6000 as ternary component to P188 solid dispersion on dissolution rate was also investigated. Formulations were characterized by Fourier transform infrared (FTIR) and Differential scanning calorimetry (DSC). Drug content uniformity and dissolution rate were studied. Solid dispersions showed a better dissolution compared to the pure drug and physical mixtures, with PVP showing the highest dissolution efficiency. As indicated from DSC data, Domperidone was in the amorphous form, which confirmed the better dissolution rate of solid dispersions. Some ternary P188 combinations showed a better enhancement in drug dissolution compared to the optimized P188 binary system. This would present a potential of increasing oral bioavailability of Domperidone by increasing its dissolution rate and by inhibiting its pre-systemic metabolism by the presence of P188.