Alginate Nanoparticles Containing Curcumin and Resveratrol: Preparation, Characterization, and In Vitro Evaluation Against DU145 Prostate Cancer Cell Line.

Curcumin and resveratrol are naturally occurring polyphenolic compounds having anti-cancer potential. However, their poor aqueous solubility and bioavailability limit their clinical use. Entrapment of hydrophobic drugs into hydrophilic nanoparticles such as calcium alginate presents a means to deliver these drugs to their target site. Curcumin and resveratrol-loaded calcium alginate nanoparticles were prepared by emulsification and cross-linking process. The nanoparticles were characterized for particle size, zeta potential, moisture content, physical state of the drugs, physical stability, and entrapment efficiency. An UPLC method was developed and validated for the simultaneous analysis of curcumin and resveratrol. Alginate nanoformulation was tested for in vitro efficacy on DU145 prostate cancer cells. The particle size of the nanosuspension and freeze-dried nanoparticles was found to be 12.53 ± 1.06 and 60.23 ± 15 nm, respectively. Both DSC and powder XRD studies indicated that curcumin as well as resveratrol were present in a non-crystalline state, in the nanoparticles. The entrapment efficiency for curcumin and resveratrol was found to be 49.3 ± 4.3 and 70.99 ± 6.1%, respectively. Resveratrol showed a higher percentage of release than curcumin (87.6 ± 7.9 versus 16.3 ± 3.1%) in 24 h. Curcumin was found to be taken up by the cells from solution as well as the nanoparticles. Resveratrol had a poor cellular uptake. The drug-loaded nanoparticles exhibit cytotoxic effects on DU145 cells. At high concentration, drug solution exhibited greater toxicity than nanoparticles. The alginate nanoformulation was found to be safe for intravenous administration.