Use of dsc and nir spectroscopy to study the hydration, degradation and drug release behavior of pla/plga microparticles and films with free and blocked carboxylic end groups

摘要

Polyesters based on poly(L-lactide) (PLLA), poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) have gained increasing interest in the field of controlled drug delivery. Since it has been demonstrated that modification of polymeric end groups might be a practicable means to control matrix hydration, matrix degradation, and thus drug release kinetics, PLA/PLGA polymers with free and blocked carboxylic end groups are presently available by commercial suppliers. Considering these aspects and the huge number of studies aiming to clarify the in vitro and in vivo degradation behavior of PLA/PLGA microspheres and implants, it is surprising that only very few papers are dealing with the effect of polymeric end groups (1).