a biologically - active compound which includes an inorganic mixed metal cationic portion having anion exchange properties and an anionic portion containing a biologically - active anion . the mixed metal cationic portion can be an oxide , hydroxide , or both , and can be fully hydrated , partially hydrated , or not hydrated . the biologically - active anion can be , e . g ., an antibiotic , an analgesic , an antimicrobial , a pharmaceutical , an antioxidant , or an agricultural chemical such as a herbicide or a pesticide . these biologically - active compounds can have controlled - release properties and can be produced by relatively simple processes , using for the cationic portion relatively common starting materials . these biologically - active compounds are useful , for example , in compositions to form pharmaceuticals , antioxidants , or herbicides , and can be incorporated into a polymeric material to form a shaped body , such as a plastic film which can be utilized to form bags for food storage or transportation . also included are processes for making the biologically - active compounds .