distribution and or enzymatic metabolism the definition of drug latentiation has also been extended to include nonenzymatic regeneration of the parent compound regeneration takes place as a consequence of hydrolytic dissociative and other reactions not necessarily enzyme mediated the terms prodrugs latentiated drugs and bio reversible derivatives are used interchangeably by inference latentiation implies a time lag element or time component involved in regenerating the bioactive parent molecule in vivo the term prodrug is general in that it includes latentiated drug derivatives as well as those substances which are converted after administration to the actual substance which combines with receptors the term prodrug is a generic term for agents which undergo biotransformation prior to exhibiting their pharmacological actions a useful reference is prodrugs challenges and rewards volumes 1 and 2 v stella r t borchardt m j hageman r oziyai h maag and j w tilley editors springer 2007 as used herein the term u201c alkyl u201d alone or in combination with other groups refers to a branched or straight chain monovalent saturated aliphatic hydrocarbon radical of one to twenty carbon atoms preferably one to sixteen carbon atoms more preferably one to ten carbon atoms the term u201c cycloalkyl u201d refers to a monovalent carbocyclic radical of three to seven preferably three to six carbon atoms this term is further exemplified by radicals such as cyclopropyl cyclobutyl cyclopentyl and cyclohexyl in a preferred embodiment the u201c cycloalkyl u201d moieties can optionally be substituted with one two three or four substituents wherein each substituent.