Role of the Pharmaceutical Excipients in the Tamoxifen Activity on MCF-7 and Vero Cell Cultures

Background: Microparticles are used for controlleddrug delivery. With the aim of improving both bioavailabilityand tamoxifen selective toxicity, the activity of tamoxifenembedded in calcium alginate/chitosan microparticles wasstudied. Materials and Methods: Tamoxifen alone andembedded in microparticles prepared with sodium alginatefrom Kelco (62% mannuronic acid and 38% guluronic acid)and from Fluka (30% mannuronic acid and 70% guluronicacid) was added to MCF-7 and Vero cultures and evaluated forantiproliferative activity by the MTT test. Results: The use ofKelco or Fluka alginate resulted in different LD50 values onVero and MCF-7 cultures, showing a higher cytotoxicitytoward Vero cells treated with tamoxifen embedded in Kelcomicroparticles (25 μM vs. 48 μM on MCF-7 cells) but aselective toxicity with Fluka microparticles (25 μM and 10 μMon Vero and MCF-7 cells respectively). Conclusion:Microparticle formulation may improve selective toxicityaccording to the alginate employed: differences in the chemicalalginate composition can dramatically change both drugactivity and toxicity.