title: Practically feasible production of sustained-release microspheres of granulocyte-macrophage colony-stimulating factor (rhGM-CSF).
abstract: Using recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) as a model drug, the present study demonstrated a practically feasible process to produce polymeric microspheres for sustained-release delivery of protein drugs with preserved integrity. This process is featured with pre-loading proteins into polysaccharide fine particles via a self-standing aqueous-aqueous "emulsion", prior to microencapsulation into the microspheres. The protein drug, rhGM-CSF, was partitioned thermodynamically into a dextran dispersed phase of the aqueous-aqueous emulsion, followed by lyophilization and removal of the polyethylene glycol (PEG) continuous phase (using an organic solvent not penetrating into dextran matrix). The harvested dextran particles were then suspended in a dichloromethane solution of polylatic-co-glyclic acids (PLGA) and emulsified in a polyvinyl alcohol (PVA) and NaCl solution of small volume to form embryonic microspheres. The emulsion was then transferred into a NaCl solution of large volume to extract the organic solvent and harden the embryonic microspheres. The obtained rhGM-CSF microspheres showed a satisfied release profile with the day-to-day variation within 9 folds over the multi-weeks long release period. At the same time, the integrity (defined freedom of aggregates measured by SEC-HPLC) and bioactivity (defined by TF-1 cell proliferation) of the proteins were well preserved. The present formulation process ensured good reproducibility and over 89% protein encapsulation efficiency, and practically feasible to adapt to scaled productions.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wu
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Dai
authors.affiliation: New Jersey Medical School, Rutgers University, 185 S. Orange Ave., Newark 07103, USA.
authors.forename: Lee
authors.initials: L
authors.lastname: Geng
authors.affiliation: New Jersey Medical School, Rutgers University, 185 S. Orange Ave., Newark 07103, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 00240, China. Electronic address: tjin@sjtu.edu.cn.
authors.forename: Tuo
authors.initials: T
authors.lastname: Jin
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D003911:Dextrans / Q000737:chemistry; D065546:Drug Liberation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D008863:Microspheres; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D017208:Rats, Wistar
chemical_list: D003692:Delayed-Action Preparations; D003911:Dextrans; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D016178:Granulocyte-Macrophage Colony-Stimulating Factor
keywords: Aqueous-aqueous emulsion; Bioactivity; Protein integrity; Sustained release microspheres; rhGM-CSF