title: Surfactant-free microspheres of poly(epsilon-caprolactone)/poly (ethylene glycol)/poly(epsilon-caprolactone) triblock copolymers as a protein carrier.
abstract: The aim of this study is to prepare biodegradable microspheres without the use of surfactants or emulsifiers for a novel sustained delivery carriers of protein drugs. A poly(epsilon-caprolactoney poly(ethylene glycol)/poly(epsilon-caprolactone) (CEC) triblock copolymer was synthesized by the ring-opening of epsilon-caprolactone with dihydroxy poly (ethylene glycol) to prepare surfactant-free microspheres. When dichloromethane (DCM) or ethyl formate (EF) was used as a solvent, the formation of microspheres did not occur. Although the microspheres could be formed prior to lyophilization under certain conditions, the morphology of microspheres was not maintained during the filtration and lyophilization process. Surfactant-free microspheres were only formed when ethyl acetate (EA) was used as the organic solvent and showed good spherical microspheres although the surfaces appeared irregular. The content of the protein in the microsphere was lower than expected, probably because of the presence of water channels and pores. The protein release kinetics showed a burst release until 2 days and after that sustained release pattern was showed. Therefore, these observations indicated that the formation of microsphere without the use of surfactant is feasible, and, this the improved process, the protein is readily incorporated in the microsphere.
authors.affiliation: College of Pharmacy, Chosun University, Gwangju 501-759, Korea.
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Sun
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Jeong
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000818:Animals; D002417:Cattle; D004337:Drug Carriers / Q000138:chemical synthesis / Q000493:pharmacokinetics; D005026:Ethylene Glycols / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D008863:Microspheres; D011091:Polyesters / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D011108:Polymers / Q000138:chemical synthesis / Q000493:pharmacokinetics; D012710:Serum Albumin, Bovine / Q000138:chemical synthesis / Q000493:pharmacokinetics; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000493:pharmacokinetics
chemical_list: D004337:Drug Carriers; D005026:Ethylene Glycols; D011091:Polyesters; D011108:Polymers; D013501:Surface-Active Agents; C476300:poly(epsilon-caprolactone)-b-poly(ethylene glycol); D012710:Serum Albumin, Bovine