Peroral Administration of super(14)C-Poly(D,L-Lactic Acid) Nanoparticles Coated with Human Serum Albumin or Polyvinyl Alcohol to Guinea Pigs

Biodegradable super(14)C-poly(D,L-lactic acid) (PLA sub(50)) nanoparticles coated either with a readily digestible protein albumin or with a non-digestible coating agent, polyvinyl alcohol (PVA), were prepared by the solvent evaporation technique. The nanoparticles were administered perorally to guinea pigs to evaluate the gastro-intestinal degradation of their PLA sub(50) matrix. In the case of PLA sub(50) nanoparticles coated with digestible albumin, substantial gastro-intestinal degradation of the PLA sub(50) matrix occurred, leading to the passage of considerable amount ( greater than or equal to 45%) of water-soluble products across the gastro-intestinal barrier. When a non-digestible coating agent like PVA was used, the degradation of the PLA sub(50) matrix in the gastro-intestinal tract was at least two times lower ( greater than or equal to 19%). The results show that it is possible to control the in vivo degradation of PLA sub(50) nanoparticles using appropriate coating agents. The present investigations showed a good correlation between previously observed in vitro results and the in vivo findings.