title: In situ forming parenteral depot systems based on poly(ethylene carbonate): effect of polymer molecular weight on model protein release.
abstract: The objective of this study was to investigate the effect of molecular weight (MW) on the drug release from poly(ethylene carbonate) (PEC) based surface-eroding in situ forming depots (ISFD). In phosphate buffered saline (PBS) pH 7.4, 63.7% of bovine serum albumin BSA was released from high MW PEC of 200 kDa (PEC200) in DMSO (15%, w/w) in 2 days, while during the same time period, the release of BSA from PEC41 samples was only 22.5%. At higher concentrations of PEC41 (25%, w/w), the initial burst was further reduced, and even after 6 days, only 16.3% was released. Compared to depots based on PEC200, there was lower rate of solvent release, slower phase inversion, and a denser surface in PEC41 samples. An expansion in size of PEC41 depots suggested that the polymer barrier of PEC41 impeded the diffusion of solvent out of the samples effectively. In conclusion, the initial burst of protein from ISFD of PEC41 was significantly reduced, which would be a promising candidate as polymeric carrier.
authors.affiliation: Department of Pharmaceutics and Biopharmacy, Philipps-Universität, Marburg, Germany.
authors.forename: Dafeng
authors.initials: D
authors.lastname: Chu
authors.forename: Catherine
authors.initials: C
authors.lastname: Curdy
authors.forename: Bernd
authors.initials: B
authors.lastname: Riebesehl
authors.forename: Moritz
authors.initials: M
authors.lastname: Beck-Broichsitter
authors.forename: Thomas
authors.initials: T
authors.lastname: Kissel
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004058:Diffusion; D016503:Drug Delivery Systems; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007263:Infusions, Parenteral; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D010316:Particle Size; D011095:Polyethylenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes; D011108:Polymers; D012997:Solvents; D014867:Water; C039212:polyethylene carbonate; D012710:Serum Albumin, Bovine
keywords: Drug release; In situ forming depots; Initial burst; Poly(ethylene carbonate); Surface-eroding polymers; Water swelling