Development and Characterization of Porous Alumina for Controlled Drug Release

Alumina is a bioceramic material used in the biomedical area as implants and as drug delivery material; it is considered an inert material, presenting good mechanical properties. Drug delivery is the process of transporting and releasing drugs into the human body in a controlled manner. Due to its characteristics, alumina was chosen as a carrier, since it must have adequate porosity to store and release the drug when implanted or grafted. Starch was used as a sacrificial material to improve porosity in the sample. Alumina samples with 5% and 10% starch addition were compared to pure alumina in relation to its porosity and mechanical properties. X-ray diffraction test confirmed the presence of the corundum structure in the alumina. The tensile strength limit by diametral compression and Young's modulus of samples presented the same value, and approximately half of the value when compared to pure alumina. Regarding porosity, the scanning electron microscope was relevant to highlight the porosity and grain differences in the samples. The mercury porosimetry assay was performed to quantify the porosity percentage, which increased with starch content and decreased with increasing final sintering temperature. In general, increasing sintering temperature reduced drug release, and increased starch content increased drug release. Therefore, it can be concluded that the samples with 5% starch presented the highest drug release in the proposed analysis.