A delivery mechanism and device for the passive periodic release of a drug or an active ingredient which avoids the need for external power sources and/or electronic controllers. By taking advantage of oscillating chemical systems, one can change the state, i.e. the pH, of a solution, a drug, enhancer...http://www.google.ca/patents/US6068853?utm_source=gb-gplus-sharePatent US6068853 - Temporally controlled drug delivery systems
