초록 |
A biodegradable triblock poly( epsi;-caprolactone)-poly(ethylene glycol)-poly( epsi;-caprolactone) copolymer was successfully synthesized by ring-opening polymerization of epsi;-caprolactone, and was characterized by intrinsic viscosimetry, 1 H nuclear magnetic resonance, infrared spectroscopy and X-ray diffraction. Copolymer microparticles loaded with ibuprofen were prepared by an oil-in-water (o/w) emulsion solvent evaporation process. They were carefully weighted and characterized through their zeta potential. In this work, 4 selected process parameters (shaking speed X 1 , time of contact X 2 , poly(vinyl alcohol) concentration X 3 , and ibuprofen concentration X 4 ) were adjusted at 2 different values. For each of the 16 experimental conditions, repeated twice, the drug encapsulation efficiency of the microspheres was determined, according to the following definition: EE (X 1 , X 2 , X 3 , X 4 )=mass of encapsulated ibuprofen/total weight of ibuprofen. A ''full factorial design method'' was applied to analyze the results statistically according to a polynomial fit and to determine the optimal conditions for the microencapsulation of the ibuprofen through an accurate statistical protocol. The microparticles obtained exhibit a spherical shape as shown by electron microscopy. |