title: Nanoparticle formulation for controlled release of capsaicin.
abstract: Capsaicin might be an effective pharmacological agent for the treatment of discogenic back pain due to its effect on pain control neuronal degeneration. Therefore, capsaicin-loaded nano- and micro-particles for sustained release were formulated by nano-precipitation or oil-in-water single emulsion solvent evaporation/extraction method. First, the capsaicin-loaded PLGA nanoparticles were prepared by nano-precipitation method. By increasing the volume of oil-water ratio from 1:2 to 1:5, slight changes in size from 162 +/- 3 nm to 153 +/- 3 nm and in drug loading efficiency from 25% to 20% were observed, whereas the drug release period was significantly changed from 11 days for 1:2 to 5 days for 1:5 ratio. To get a more sustained release, a modified single emulsion method was applied with three kinds of biocompatible polymers (PLLA, PLGA, and PCL). Among them, PLLA particles showed a much sustained release profile than PLGA or PCL ones with the similar size. For PLLA particles, particles size and drug encapsulation efficiency increased as the oil/water ratio decreased, and the bigger particles showed the slower release profiles as well as the higher drug-loading efficiency, thus about 1 month release was obtained with 800 nm particles. In conclusion, formulation for the controlled release of capsaicin from 1 week to 1 month was prepared by using biocompatible nanoparticles.
authors.affiliation: Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712, Korea.
authors.forename: Seon
authors.initials: S
authors.lastname: Kim
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Donggeun
authors.initials: D
authors.lastname: Sul
authors.forename: Sun Wook
authors.initials: SW
authors.lastname: Hwang
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Lee
authors.forename: Young Ha
authors.initials: YH
authors.lastname: Kim
authors.forename: Giyoong
authors.initials: G
authors.lastname: Tae
mesh_terms: D002211:Capsaicin / Q000008:administration & dosage* / Q000737:chemistry; D003692:Delayed-Action Preparations; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles; D010316:Particle Size; D018689:Sensory System Agents / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D018689:Sensory System Agents; D002211:Capsaicin