Controlling the structure of spin-coated multilayer ethylcellulose/hydroxypropylcellulose films for drug release
Journal article, 2023
Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. Water-soluble HPC leaches out and forms a porous structure that controls the drug transport. Industrially, the pellets are coated using a fluidized bed spraying device, and a layered film exhibiting varying porosity and structure after leaching is obtained. A detailed understanding of the formation of the multilayered, phase-separated structure during production is lacking. Here, we have investigated multilayered EC/HPC films produced by sequential spin-coating, which was used to mimic the industrial process. The effects of EC/HPC ratio and spin speed on the multilayer film formation and structure were investigated using advanced microscopy techniques and image analysis. Cahn-Hilliard simulations were performed to analyze the mixing behavior. A gradient with larger structures close to the substrate surface and smaller structures close to the air surface was formed due to coarsening of the layers already coated during successive deposition cycles. The porosity of the multilayer film was found to vary with both EC/HPC ratio and spin speed. Simulation of the mixing behavior and in situ characterization of the structure evolution showed that the origin of the discontinuities and multilayer structure can be explained by the non-mixing of the layers.
Confocal laser scanning microscope
Electron microscopy
Cellulose
Phase separation kinetics
Porous film for controlled release
Multilayer film
Cahn-Hilliard simulations
Phase separation mechanisms
Author
Pierre Carmona
RISE Research Institutes of Sweden
Chalmers, Physics, Nano and Biophysics
Jens Poulsen
Wendelsbergs beräkningskemi AB
Jan Westergren
Wendelsbergs beräkningskemi AB
Torben Nilsson Pingel
RISE Research Institutes of Sweden
Magnus Röding
Chalmers, Mathematical Sciences, Applied Mathematics and Statistics
RISE Research Institutes of Sweden
Eileen Lambrechts
RISE Research Institutes of Sweden
Ghent university
Herlinde De Keersmaecker
Ghent university
Kevin Braeckmans
Ghent university
Aila Särkkä
Chalmers, Mathematical Sciences, Applied Mathematics and Statistics
Christian von Corswant
AstraZeneca AB
Eva Olsson
Chalmers, Physics, Nano and Biophysics
Niklas Lorén
RISE Research Institutes of Sweden
Chalmers, Physics, Nano and Biophysics
International Journal of Pharmaceutics
0378-5173 (ISSN) 1873-3476 (eISSN)
Vol. 644 123350Extracting information from complicated point patterns
Swedish Research Council (VR) (2018-03986), 2019-01-01 -- 2022-12-31.
Subject Categories
Chemical Sciences
DOI
10.1016/j.ijpharm.2023.123350
PubMed
37640089