title: Micro- and macrostructural characterization of polyvinylpirrolidone rotary-spun fibers.
abstract: The application of high-speed rotary spinning can offer a useful mean for either preparation of fibrous intermediate for conventional dosage forms or drug delivery systems. Polyvinylpyrrolidone (PVP) and poly(vinylpyrrolidone-vinylacetate) (PVP VA) micro- and nanofibers of different polymer concentrations and solvent ratios were prepared with a high-speed rotary spinning technique. In order to study the influence of parameters that enable successful fiber production from polymeric viscous solutions, a complex micro- and macrostructural screening method was implemented. The obtained fiber mats were subjected to detailed morphological analysis using scanning electron microscope (SEM), and rheological measurements while the microstructural changes of fiber samples, based on the free volume changes, was analyzed by positron annihilation lifetime spectroscopy (PALS) and compared with their mechanical characteristics. The plasticizing effect of water tracked by ortho-positronium lifetime changes in relation to the mechanical properties of fibers. A concentration range of polyvinylpyrrolidone solutions was defined for the preparation of fibers of optimum fiber morphology and mechanical properties. The method enabled fiber formulation of advantageous functionality-related properties for further formulation of solid dosage forms.
authors.affiliation: a University Pharmacy Department of Pharmacy Administration, Semmelweis University , Budapest , Hungary .
authors.forename: István
authors.initials: I
authors.lastname: Sebe
authors.affiliation: b Department of Pharmaceutics , Semmelweis University , Budapest , Hungary , and.
authors.forename: Barnabás
authors.initials: B
authors.lastname: Kállai-Szabó
authors.affiliation: c Department of Polymer Engineering , Faculty of Mechanical Engineering, Budapest University of Technology and Economics , Budapest , Hungary.
authors.forename: Krisztián Norbert
authors.initials: KN
authors.lastname: Kovács
authors.affiliation: b Department of Pharmaceutics , Semmelweis University , Budapest , Hungary , and.
authors.forename: Enikő
authors.initials: E
authors.lastname: Szabadi
authors.affiliation: a University Pharmacy Department of Pharmacy Administration, Semmelweis University , Budapest , Hungary .
authors.forename: Romána
authors.initials: R
authors.lastname: Zelkó
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers; D011108:Polymers / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*; D012212:Rheology; D012997:Solvents / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D011108:Polymers; D011759:Pyrrolidines; D012997:Solvents; D014753:Vinyl Compounds; C402301:poly(vinylpyrrolidone-co-vinyl-acetate); D014867:Water; D011205:Povidone
keywords: Electron microscopy; fibres; high-speed rotary spinning; mechamical properties; microstructures