Poly(N-vinyl-pyrrolidone)-block-poly(D,L-lactide) as polymeric emulsifier for the preparation of biodegradable nanoparticles

✍ Scribed by Geneviève Gaucher; Monika Poreba; François Ravenelle; Jean-Christophe Leroux

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 194 KB
• Volume: 96
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.20833

✦ Synopsis

Poly(D,L-lactide) (PDLLA) amphiphilic block copolymers were employed as emulsifiers in the preparation of PDLLA nanoparticles by an oil/water emulsion solvent evaporation technique. The surface-active properties of poly(N-vinyl-pyrrolidone)-blockpoly(D,L-lactide) (PVP-b-PDLLA) toward the biphasic system were compared to those of polyethylene glycol(PEG)-b-PDLLA of similar composition. PVP-b-PDLLA was found to be a suitable emulsifier for dichloromethane/water emulsions, yielding narrowly distributed nanoparticles (<250 nm) surrounded by a hydrophilic PVP corona. PEG-b-PDLLA, however, was only effective in producing appropriately sized nanoparticles when dichloromethane was replaced with ethyl acetate. Furthermore, the lyoprotectant properties of PVP allowed the freeze-dried nanoparticles to recover their initial size following reconstitution, while PEG-coated nanoparticles could not be redispersed following lyophilization. Two poorly water-soluble drugs, that is, paclitaxel and etoposide, were efficiently loaded into PVP-decorated PDLLA nanoparticles. The entrapment efficiency of etoposide was significantly enhanced by adding MgCl 2 to the aqueous phase. It was found that the nanoparticles released the drugs progressively over several days in vitro. The obtained experimental results were corroborated with the theoretical compatibility between a given drug, polymer, and solvent, predicted by total solubility parameters.