Please use this identifier to cite or link to this item: https://ir.swu.ac.th/jspui/handle/123456789/15337
ชื่อเรื่อง: Modeling plasticizer uptake in aqueous polymer dispersions
ผู้แต่ง: Siepmann J.
Paeratakul O.
Bodmeier R.
Keywords: ethyl cellulose
plasticizer
polymer
article
controlled study
diffusion coefficient
dispersion
drug coating
drug diffusion
drug dosage form
drug penetration
drug solubility
kinetics
model
nonhuman
priority journal
temperature
วันที่เผยแพร่: 1998
บทคัดย่อ: The mass transport of water-insoluble plasticizers, emulsified in an aqueous, colloidal polymer dispersion (Aquacoat®) was investigated. A model was developed, which allows quantitative predictions and gives further insight into the transfer mechanism. Experiments proved the validity of the model under various conditions. There are two important mass transfer processes: (1) dissolution of the plasticizer droplets and (2) diffusion of the plasticizer within the polymer particles. Initially, after adding the plasticizer to the aqueous dispersion, dissolution governs the kinetics (dissolution rate < diffusion rate). But increasing amounts of plasticizer located within the polymer particles lead to decreasing concentration gradients and subsequent declining diffusion rates. A change of the governing mechanism is observed. During the final portion, diffusion controls the transfer kinetics (dissolution rate > diffusion rate). Dissolution and diffusion are taken into account simultaneously in the new model, which was used to determine the diffusion coefficients and dissolution rate constants of various plasticizers. Knowing these parameters, the minimum stirring time, necessary for a complete plasticizer uptake (to avoid inhomogeneous coatings) can be calculated.
URI: https://ir.swu.ac.th/jspui/handle/123456789/15337
https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032516214&doi=10.1016%2fS0378-5173%2897%2900390-6&partnerID=40&md5=d8cf0f9a6b61fcee93236a5a63217f87
ISSN: 3785173
Appears in Collections:Scopus 1983-2021

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