Provided are cap layer compositions and base layer compositions, providing
quick and extended release of an active ingredient, respectively, when
placed in water. Further provided are dual release compositions including
a base composition and a cap composition. The base composition may
include a plaster and an active agent, and it may further include at
least one of a water-soluble binder, a non-water-soluble binder, and a
lubricant. The cap composition may include a plaster and an active agent,
and it may further include at least one of a disintegrating agent, a
non-water-soluble binder, and a lubricant. The compositions may be heated
and mixed and formed into a tablet. Further provided are methods of
making the compositions. Further provided are methods of controlling or
eliminating pests and methods of increasing the potability of water. The
compositions are effective for controlling or eliminating pests such as
mosquitoes when applied at an application site.