Original Articles
Yaowalak Srisuwan and Yodthong
Abstract
In this study, the influence of the D-/L-form mole ratio of lactic acid on poly(D,L-lactide) (PDLLA) properties and its drug release behaviors were investigated and discussed. The PDLLAs were synthesized by ring-opening polymerization of DLLA monomers. The DLLA monomers with different D-/L-form ratios were prepared by polycondensation followed by a thermal decomposition processes for the D,L-/L-lactic acid mixtures. All the PDLLAs were complete amorphous for the D,L-/L-lactic acid mole ratios of 100/0-50/50. Indomethacin, a poorlywater soluble model drug was entrapped in the PDLLA microparticles. All drug-loaded PDLLA microparticles prepared by the oil-in-water emulsion solvent evaporation method were spherical in shape and had a smooth surface. In vitro drug release behaviors showed that the drug release from the PDLLA microparticles prepared with different D-/L-form ratios was similar. It is considered that the PDLLAs with a higher L-form ratio have the potential to be developed further as a lower-cost PDLLA for use in controlled release drug delivery applications