Article

Pulsatile drug delivery systems using hydrogels

Department of Chemical Engineering, Waseda University, Tokyo, Japan; Institute of Biomedical Engineering, Tokyo Women's Medical College, Tokyo, Japan
Advanced Drug Delivery Reviews 01/1993; DOI: 10.1016/0169-409X(93)90028-3

ABSTRACT In recent years, temporal control of drug delivery has been of interest to achieve improved drug therapies. Intelligent drug delivery systems (DDS) are one expected result, demonstrating an ability to sense external environmental changes, judge the degree of external signal, and release appropriate amounts of drug. Intelligent DDS may be achieved using stimuli-responsive polymeric hydrogels which alter their structure and physical properties in response to external stimuli. Pulsatile drug release has the advantages of avoiding drug tolerance or matching the body's release of specific peptides or hormones. In this review, recent studies for pulsatile drug delivery in response to stimuli such as chemical agents, pH, electric fields, and temperature are discussed. Achievement of pulsatile drug release from stimuli-responsive polymeric hydrogels as on-off switches and its mechanism are reviewed in terms of control for stimuli-responsive swelling.

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