4 9 5 CONTROLLED ACTIVATION INGESTIBLE IDENTIFIER ABSTRACT 10 CONTROLLED ACTIVATION IDENTIFIERS FOR USE IN INGESTIBLE COMPOSITIONS, SUCH AS PHARMA-INFORMATICS ENABLED COMPOSITIONS, ARE PROVIDED. THE IDENTIFIERS INCLUDE A CONTROLLED ACTIVATION ELEMENT THAT PROVIDES FOR ACTIVATION OF THE 15 IDENTIFIER IN RESPONSE TO THE PRESENCE OF A PREDETERMINED STIMULUS AT A TARGET SITE OF INTEREST. THE INVENTION FINDS USE IN A VARIETY OF DIFFERENT APPLICATIONS, INCLUDING BUT NOT LIMITED TO, MONITORING OF THERAPEUTIC REGIMEN COMPLIANCE, TRACKING THE HISTORY OF PHARMACEUTICAL AGENTS, ETC. 20 (FIG. 10) 0 2