Formulation and evaluation of curcumin microsponges for oral and topical drug delivery

The aim of the present study was to improve the release rate of curcumin by microsponges prepared through quasi-emulsion solvent diffusion technique using ethylcellulose and PVA as carriers. The microsponges were characterized by FTIR, DSC, XRD and SEM studies followed by determination of total drug content and entrapment efficiency. The prepared microsponges were further filled in hard gelatin capsule shell and then loaded in carbopol gel to evaluate its potential in oral and topical drug delivery. Further, it was observed from the studies on release rate that microsponges filled in hard gelatin capsule shells (batch MS4) showed 93.2% release of curcumin whereas pure curcumin filled in capsule showed only 11.7% release in 8 h study. Furthermore, the microsponges loaded in carbopol gel were evaluated for ex vivo drug deposition studies and it was found that 77.5% of the curcumin was released within 24 h. The estimated drug remained in the skin was 207.61 ± 5.03 μg/cm² as determined by a Franz diffusion cell. The drug release profile data were found to be fitted best into the zero-order model with anomalous transport mechanism of drug release in both cases.