No abstract

Alginate based microparticle drug delivery systems were prepared for the sustained release of antitumor drugs. Two drugs, cyclophosphane and 5-fluorouracil, were encapsulated into the microparticles. The drug loaded microparticles were fabricated using a very convenient method under very mild conditions by the gelation of alginate with calcium cation. Modified microparticles were obtained by syringed dropwise a solution of drugs in sodium alginate into chitosan solution in calcium chloride. The effect of polymers concentration and the drug loading (1.0, 5.0 and 10%) on the release profile of drugs were investigated. The amount of drug release was much higher initially (approximately 25%), followed by a constant slow release profile. All the release data show the typical pattern for a matrix controlled mechanism. The cumulative amount of drug released from alginate gels was linearly related to the square root of the time and the release rate decreased this time. The process is controlled by the diffusion of antitumor drugs through the chitosan coating. Scanning electron microscopy (SEM) and particle size analysis revealed differences between the formulations as to their appearance and size distribution. The experiments for anticancer action of alginate microparticles were determined at 120 inbreeded white rats (females, weight 120-125 g, age 2-3 month) infected by malignant Rhabdomyoma strain at the dose of 10 000 cells. Medical-biological tests show that the duration of anticancer activity for the drug-containing alginate microparticles increases at 5-8 times in comparison of free drugs. Such systems may have potential for controlled delivery of antitumor drugs for the treatment of eye cancer.