Experimental Approaches for Achieving Both Zero-Order and Modulated Controlled Release from Polymer Matrix Systems

  • S. T. Hsieh
  • Robert Langer


One of the major drawbacks of all practical approaches thus far developed for fabricating diffusion-controlled matrices for drug delivery is that the release rates decrease with time. From a pharmaceutical standpoint, it would be desirable for, many such systems to display zero-order release kinetics. Furthermore, in some circumstances (e.g., insulin delivery in diabetics) it would be useful to be able to achieve increased dosages on demand. In the present study, we present experimental approaches for achieving both of these objectives.


Magnetic Bead Sodium Salicylate Steel Bead Average Release Rate Thomas Rotating 
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Copyright information

© Springer Science+Business Media New York 1981

Authors and Affiliations

  • S. T. Hsieh
    • 1
    • 2
  • Robert Langer
    • 1
    • 2
  1. 1.Department of Nutrition and Food ScienceM.I.T.CambridgeUSA
  2. 2.Department of SurgeryChildren’s Hospital Medical CenterBostonUSA

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