(748d) Scale-up of Polyanhydride Particle Synthesis Methods and Their Effect On Drug Release Kinetics

Polyanhydrides are biodegradable materials which have been shown to provide sustained
delivery of their encapsulated payloads. Copolymers based upon sebacic acid (SA), 1,6-bis-(p-carboxyphenoxy)hexane
(CPH), and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaocatane (CPTEG) have previously
been synthesized into therapeutic loaded particles through solvent
precipitation in our lab. Techniques have been established for the production
of polyanhydride particles that are polydisperse on both the micron and nano
scale. However, the solvent precipitation method is a batch operation which is
not easily scalable.  Therefore, in this
work we evaluate the synthesis of polyanhydride
particles through solvent evaporation via spray drying, a more easily scalable
process. The operating parameters of the spray dryer were optimized with
respect to particle yield. Model drugs were encapsulated into the polyanhydride particles to determine encapsulation
efficiency and for studies on release kinetics. The resulting polymer particles
were also compared to the particles synthesized through a solvent precipitation
method for physical particle characteristics (size, surface characteristics,
shape and porosity). From these results we show that the method of particle
synthesis plays an important role in the performance of drug loaded polyanhydride particles.