In situforming poly(lactic acid-co-glycolic acid) implants containing leuprolide acetate/β-cyclodextrin complexes: preparation, characterization, andin vitrodrug release

In situ forming implants (ISIs) based on poly(lactic acid-co-glycolic acid) (PLGA) containing leuprolide acetate/β-cyclodextrin (LA/β-CD) complexes were prepared. Incorporation of LA or complexes did not change Tg values of ISIs (48.4–49.6°C). ISIs containing complexes with more β-CD content showed higher surface and bulk porosity. Higher β-CD portion in complexes improved solvent release, decreased initial burst release and facilitated diffusion out of drug for corresponding ISIs. Complexation of LA with β-CD (1/10, w/w) significantly improved its stability within PLGA matrix before release (total LA release of 91.3%). ISIs did not show any cellular cytotoxic effects against L929 fibroblast cells.