P Bouillot1, V Babak, E Dellacherie. 1. Laboratoire de Chimie Physique Macromoleculaire, ENSIC, Nancy, France. p.bouillot@bris.ac.uk
Abstract
PURPOSE: The objective of this work is to prepare microspheres by the emulsion-solvent evaporation process using MPOE-PLA copolymers as the matrix material and/or the surfactant. This preparation was studied in order to avoid the use of PVA as the surfactant in the process. METHODS: Two series of MPOE-PLA copolymers were synthesised. The first, with a long and constant length PLA chain (45,000 g.mol(-1), was used as the matrix material, the second, with short PLA chains (< or = 2.200 g.mol(-1)), and different HLB as the surfactant. Microspheres were prepared by the "simple" and "double" emulsion methods. The steric stabilization effect of the copolymers was investigated using confocal microscopy and X-ray photoelectron spectroscopy (XPS). RESULTS: Confocal microscopy and XPS analysis showed that the microspheres prepared using MPOE5K-PLA0.5K as the surfactant and MPOE-PLA45K copolymers as the matrix material had an MPOE coating present at the microsphere surface. This hydrophilic layer ensures steric stabilization of the particles. CONCLUSIONS: MPOE-PLA copolymers can be used for the preparation of particles instead of PVA and their use can be extended whenever a biocompatible and bioeliminable surfactant is required for biological or medical applications.
PURPOSE: The objective of this work is to prepare microspheres by the emulsion-solvent evaporation process using MPOE-PLA copolymers as the matrix material and/or the surfactant. This preparation was studied in order to avoid the use of PVA as the surfactant in the process. METHODS: Two series of MPOE-PLA copolymers were synthesised. The first, with a long and constant length PLA chain (45,000 g.mol(-1), was used as the matrix material, the second, with short PLA chains (< or = 2.200 g.mol(-1)), and different HLB as the surfactant. Microspheres were prepared by the "simple" and "double" emulsion methods. The steric stabilization effect of the copolymers was investigated using confocal microscopy and X-ray photoelectron spectroscopy (XPS). RESULTS: Confocal microscopy and XPS analysis showed that the microspheres prepared using MPOE5K-PLA0.5K as the surfactant and MPOE-PLA45K copolymers as the matrix material had an MPOE coating present at the microsphere surface. This hydrophilic layer ensures steric stabilization of the particles. CONCLUSIONS: MPOE-PLA copolymers can be used for the preparation of particles instead of PVA and their use can be extended whenever a biocompatible and bioeliminable surfactant is required for biological or medical applications.
Authors: S Stolnik; S E Dunn; M C Garnett; M C Davies; A G Coombes; D C Taylor; M P Irving; S C Purkiss; T F Tadros; S S Davis Journal: Pharm Res Date: 1994-12 Impact factor: 4.200