Fabrication of PLGA forming implants and study on their correlation of release profiles with performances.

In this study, a novel PLGA forming implants (ISFIs) were fabricated and methods for testing the release profiles were also developed. The correlations between release profiles and performances ( correlation, IVIVC) were also studied. PLGA with different molecular weights were selected as the polymeric matrix. Biocompatible -methy1-2-pyrrolidone (NMP) or glyceryl triacetate (GTA) were used as the solvents with the ratios of NMP/GTA from 60/40 (vol/vol) to 20/80 (vol/vol). Eprinomectin (EPR) was chosen as the model therapeutic. release profiles of the EPR-loaded PLGA ISFIs were investigated using various methods (i.e. 'tubule' sample-and-separate and dialysis method). Sprague-Dawley rats were used to study the pharmacokinetics of EPR-loaded PLGA ISFIs. The release data obtained 'tubule' sample-separate method had a good IVIVC (Level A, > 0.99). These results showed that the 'tubule' sample-separate method was capable of discriminating the EPR-loaded ISFIs which were equivalent in formulation composition with manufacturing differences. Meanwhile, this method could be used to predict the performances of ISFIs in the investigated animal model.