Controlled-release technologies are developed to deliver drugs, proteins, pesticides, fragrances, and other bioactive agents at a controlled rate for a desired time period to maintain a constant and effective level of an active ingredient. Controlled-release formulations provide greater efficacy, convenience, and improved safety by maintaining optimal concentrations of the active ingredient. Many controlled-release technologies operate by diffusion of the active ingredient or water through a rate-controlling membrane and can be classified into four categories: (1) reservoir types, (2) matrix systems, (3) swelling-controlled systems, and (4) osmotic systems.
In reservoir (membrane) systems, the bioactive agent is either encapsulated by two semipermeable membranes or core containing the active ingredient is surrounded by a semipermeable membrane. Diffusivity and solubility of the active ingredient in the membrane are two key parameters that influence the rate of diffusion through the...
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© 2013 Springer-Verlag Berlin Heidelberg
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Alsoy Altinkaya, S. (2013). Controlled Release. In: Drioli, E., Giorno, L. (eds) Encyclopedia of Membranes. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-40872-4_1236-1
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DOI: https://doi.org/10.1007/978-3-642-40872-4_1236-1
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Publisher Name: Springer, Berlin, Heidelberg
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