Abstract
Geometrical features such as shape and surface area of a drug-releasing matrix affect drug release kinetics by changing diffusion rates across the matrix, lengthening the diffusion pathway through drug–matrix composition or simply presenting a different surface area to the dissolution medium. Such variables can change during the dissolution process, due to drug depletion or erosion or dissolution of release-modifying components. Such phenomena can help the development of novel dosage units since they present opportunities to capitalize on shape and surface effects designing a matrix that optimally delivers drug at the required rate. The historical development and state-of-the-art of geometrically designed dosage forms are presented in this chapter.
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© 2011 Controlled Release Society
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Colombo, P., Colombo, G., Cahyadi, C. (2011). Geometric Release Systems: Principles, Release Mechanisms, Kinetics, Polymer Science, and Release-Modifying Material. In: Wilson, C., Crowley, P. (eds) Controlled Release in Oral Drug Delivery. Advances in Delivery Science and Technology. Springer, Boston, MA. https://doi.org/10.1007/978-1-4614-1004-1_11
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DOI: https://doi.org/10.1007/978-1-4614-1004-1_11
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