[Kinetics of methyluracil release from bioresorbable polymeric carriers]

Bioresorbable poly(lactic-co-glycolic) matrix-carriers containing 20 wt. % of 6-methyluracil (MU) have been prepared by supercritical fluid monolithization without organic solvents. Raman spectroscopy was used to analyze both the spatial distribution MU over polymer matrices and the MU release kinetics from the carrier into phosphate buffer solution. It was found that, during the first 24 h, the amount of released MU did not exceed 15-20% of its encapsulated content. After that, the MU release kinetics passed to almost linear regime with simultaneous retarding of the process. On the 40th day of observation, the MU content in solution reached up to 80% of its initial content in the carriers. Thus, using 6-methyluracil as a model, it was shown that the proposed bioresorbable and bioactive composites can be used as matrix-carriers for targeted and long-term drug release.