title: Mathematical modelling of the drug release from an ensemble of coated pellets.
abstract: Coated pellets are widely used as oral drug delivery systems, being highly accepted by patients and with several advantages compared to single unit devices. However, their behaviour needs to be elucidated so as to improve the effectiveness of the formulations and reduce production costs. In spite of this important issue, few mathematical modelling studies have been attempted, mostly due to the complexities arising from the system's polydispersity (non-homogeneous multiple-unit particulate systems), which has been scarcely investigated using mechanistic models.
  
  
  
  A mechanistic mathematical model was developed that was able to describe the single pellet behaviour in terms of hydration, drug dissolution, diffusion and release and particle size. This model was then extended to describe and predict the behaviour of mono- and polydispersed ensembles of pellets.
  
  
  
  The polydispersity arising from the size and distribution of the inert core was shown to have a minimal effect on the drug release profile, whereas the thickness and distribution of the polymeric film was found to be the key parameter determining the drug release.
  
  
  
  The mechanistic model developed, which is capable of determining the polydispersity of the drug delivery system, was able to predict the release kinetics from ensembles of pellets and to highlight the key parameters that need to be controlled in the production of pellet-based drug delivery systems, demonstrating its use as a powerful predictive tool.
authors.affiliation: Department of Industrial Engineering, University of Salerno, Fisciano, SA, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Caccavo
authors.affiliation: Department of Industrial Engineering, University of Salerno, Fisciano, SA, Italy.
authors.forename: Gaetano
authors.identifier: 0000-0003-1689-6887
authors.initials: G
authors.lastname: Lamberti
authors.affiliation: Department of Industrial Engineering, University of Salerno, Fisciano, SA, Italy.
authors.forename: Maria Margherita
authors.initials: MM
authors.lastname: Cafaro
authors.affiliation: Department of Pharmacy, University of Salerno, Fisciano, SA, Italy.
authors.forename: Anna Angela
authors.initials: AA
authors.lastname: Barba
authors.affiliation: AstraZeneca R&S, Mölndal, Sweden.
authors.forename: Jurgita
authors.initials: J
authors.lastname: Kazlauske
authors.affiliation: Pharmaceutical Technology, Department of Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden.|SuMo BIOMATERIALS, A VINNOVA VINN Excellence Center, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Anette
authors.initials: A
authors.lastname: Larsson
mesh_terms: D003692:Delayed-Action Preparations / Q000737:chemistry*; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004343:Drug Implants / Q000737:chemistry*; D008956:Models, Chemical; D010316:Particle Size; D012995:Solubility; D013499:Surface Properties
chemical_list: D003692:Delayed-Action Preparations; D004343:Drug Implants