Sustained-release solid dispersions of ibuprofen prepared by microwave irradiation

The paper is devoted to the investigation of microwave irradiation (MW) for the preparation of solvent free solid dispersion (SD). Precisely, sustained release solid dispersions containing different drug-to-polymer ratios were developed by means of microwave technology using ibuprofen (IBU) as a model drug and glyceryl monostarate (Imwitor 900, GM) as a lipophilic sustained release agent. Their physical characterizations were determined by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), hot-stage microscopy (HSM). Through the dissolution rates studies, the in vitro drug performance of the SD was evaluated. The physical characterizations revealed a substantial correspondence of the drug solid state before and after MW treatment while drug-carrier interactions in the SD were attested. The dissolution studies of the irradiated samples showed that the matrices based on Imwitor 900 were able to promote a sustained release of the drug. A mathematical approach suggested that IBU release from solid dispersion was essentially due to matrix erosion. In conclusion we can affirm that the microwave technique could be considered as a new and interesting method to prepare drug-carrier systems.