Controlled Production of Poly (3-Hydroxybutyrate-co-3-Hydroxyhexanoate) (PHBHHx) Nanoparticles for Targeted and Sustained Drug Delivery

The ability to control the size and quality of nanoparticles (NPs) during production is critical for their success as a commercial product for clinical applications. Here, we employed a statistical design of experiment approach to identify the key process variables affecting the size of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) NPs during production via the solvent evaporation method. The number of sonication cycles had a standardzed effect on NP size of 55, with sonication power at 25, and PHBHHx concentration at 27 with a combination of these variables having a lower yet significant effect on NP size (p < 0.05). The PHBHHx NPs were stable for at least 7 days with an average polydispersity index of 0.18, a zeta potential of −10 to −40 mV, and an encapsulation efficiency of 63.5 ± 2%. These data were utilized to produce a prediction graph whereby particles could be produced with sizes ranging from 90 to 205 nm with a low mean curve prediction error of 1.96% for Haperzine-A-loaded NPs. Furthermore, a range of drug encapsulates NPs were produced and showed a sustained release of the encapsulated drug. This study demonstrates the ability to control the size of drug-loaded particles by manipulation of the production variables, which will allow targeted and controlled drug release to fit a variety of applications. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2498-2508, 2014