title: PLGA microsphere bioburden evaluation for radiosterilization dose selection.
abstract: The aim of this study was to determine the bioburden of PLGA microspheres produced by the solvent emulsion/extraction process as a means of determining an appropriate gamma-irradiation dose for sterilization. Bioburden was evaluated on the basis of ISO specifications. The analysis of initial microbial contamination was performed on blank microspheres, prepared by a non-aseptic laboratory scale process. A mean bioburden of 36.04 CFU (colony forming units)/110 mg microspheres was determined. Most of the detected germs originated from human commensal flora. According to the ISO dose-selection method, a gamma-irradiation dose of 19.6 kGy was found sufficient to ensure a sterility level of 10(-6). The effect of the selected irradiation dose on both the molecular weight of the polymer and the kinetics of 5-fluorouracil drug release from the microspheres was compared to the European Pharmacopeia recommended irradiation dose (25 kGy). This 20% reduced dose showed a lower extent of molecular weight reduction of PLGA and a better control of 5-FU release from microparticles. This can be related to reduce polymer radiation damage.
authors.affiliation: UPRES EA 2169, Faculté de Pharmacie, Angers, France.
authors.forename: A
authors.initials: A
authors.lastname: Gèze
authors.forename: M C
authors.initials: MC
authors.lastname: Venier-Julienne
authors.forename: J
authors.initials: J
authors.lastname: Cottin
authors.forename: N
authors.initials: N
authors.lastname: Faisant
authors.forename: J P
authors.initials: JP
authors.lastname: Benoit
mesh_terms: D005472:Fluorouracil / Q000008:administration & dosage / Q000737:chemistry; D005720:Gamma Rays; D019344:Lactic Acid / Q000528:radiation effects*; D008863:Microspheres; D008970:Molecular Weight; D011100:Polyglycolic Acid / Q000528:radiation effects*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000528:radiation effects*; D011829:Radiation Dosage; D012995:Solubility; D013242:Sterilization
chemical_list: D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005472:Fluorouracil