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.

• Electron microscopy
• fibres
• high-speed rotary spinning
• mechamical properties
• microstructures

Acknowledgements

The authors are grateful to Károly Süvegh (Laboratory of Nuclear Chemistry, Eötvös Loránd University/HAS Chemical Research Center) for the possibility of the use of PALS equipment, to László Zsidai and István Oldal for the design of the spinneret, to Máté Petzke for the valuable contribution in the preparation of rotary-spun fibers.

Declaration of interest

The authors report that they have no conflicts of interest.