An asymptotic model for the primary drying stage of vial lyophilization
2016 (English)In: Journal of Engineering Mathematics, ISSN 0022-0833, E-ISSN 1573-2703, Vol. 96, no 1, 175-200 p.Article in journal (Refereed) Published
Asymptotic methods are employed to analyse a commonly used one-dimensional transient model for coupled heat and mass transfer in the primary drying stage of freeze-drying (lyophilization) in a vial. Mathematically, the problem constitutes a two-phase moving boundary problem, in which one of the phases is a frozen porous matrix that undergoes sublimation, and the other is a low-pressure binary gaseous mixture. Nondimensionalization yields a model with 19 dimensionless parameters, but a systematic separation of timescales leads to a reduced model consisting of just a second-order differential equation with two initial conditions for the location of a sublimation front; the temperature and gas partial pressures can be found a posteriori. The results of this asymptotic model are compared with those of earlier experimental and theoretical work. Most significantly, the current model would be a computationally efficient tool for predicting the onset of secondary drying.
Place, publisher, year, edition, pages
Kluwer Academic Publishers, 2016. Vol. 96, no 1, 175-200 p.
Asymptotics, Freeze-drying, Pharmaceuticals, Vial, Differential equations, Drug products, Low temperature drying, Mass transfer, Sublimation, Computationally efficient, Coupled heat and mass transfer, Dimensionless parameters, Freeze drying, Moving boundary problems, Second-order differential equation, Drying
IdentifiersURN: urn:nbn:se:kth:diva-175038DOI: 10.1007/s10665-015-9789-7ISI: 000372576200010OAI: oai:DiVA.org:kth-175038DiVA: diva2:876359
QC 20151203, QC 201604202015-12-032015-10-092016-04-20Bibliographically approved