Lidocaine-loaded biodegradable nanospheres. I. Optimization Of the drug incorporation into the polymer matrix.
Spherical nanoparticulate drug carriers made of poly(d,l-lactic acid) with controlled size were designed. A local anesthetic, lidocaine, a small hydrophobic molecule, was incorporated in the core with loadings varying from about 7 to 32% (w/w) and increasing with the particle size. Particles with sizes from about 250 to 820 nm and low polydispersity were prepared with good reproducibility; the polymer concentration (at constant surfactant concentration) governed the particle size. The large particles with a high loading ( approximately 30%) showed under in vitro conditions a slow release over 24-30 h, the medium sized carriers (loading of approximately 13%) released the drug over about 15 h, whereas the small particles with small loading ( approximately 7%) exhibited a rapid release over a couple of hours. It seems that the drug release rate is related to the state (crystallized or dispersed) of the drug incorporated in the polymer matrix.
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Laboratoire de Chime Physique Macromoléculaire, UMR CNRS-INPL 7568, Ecole Nationale Supérieure des Industries Chimiques, 1, rue Grandville, BP 451, 54001 Nancy Cedex, France.
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D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D002850:Chromatography, Gel; D016503:Drug Delivery Systems; D007700:Kinetics; D019344:Lactic Acid; D008012:Lidocaine / Q000008:administration & dosage* / Q000737:chemistry; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters; D011108:Polymers; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
D000779:Anesthetics, Local; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D008012:Lidocaine