TESTING OF IN-VITRO DISSOLUTION BEHAVIOR OF MICROPARTICULATE DRUG-DELIVERY SYSTEMS

No official dissolution method exists concerning microparticulate drug delivery systems. The purpose of this work is the evaluation of different dissolution methods commonly used to test the in vitro release behaviour of microparticulate drug delivery systems. The influence of different environmental conditions, as stirring speed, ionic strength and presence of surfactant, on drug release is also evaluated. Four dissolution methods, based on different equipments (USP dissolution test apparatus, rotating bottle apparatus, shaker incubator, recycling flow through cell), are performed on the same batch of indomethacin loaded poly-D,L-lactide (PDLLA) microspheres prepared by spray drying. The results obtained with the methods tested show the influence of in vitro dissolution method employed and of the environmental conditions on drug release profile