Abstract: The present invention provides an intra-ruminal device comprising a body substantially impervious to rumen fluid, the body comprising a barrel, at least one outlet, and at least one matrix in the barrel, a compression arrangement within the body adapted to bias the column of matrices in the barrel to the at least one outlet, and at least one variable geometry device dependent from the body to assist numen retention, wherein the at least one matrix in the barrel comprises at least one active ingredient and at least one polymer selected from the group consisting of a non-ionic polymer and a cross-linked anionic polymer. The invention also provides a method of making and using the device.

Abstract: The present invention relates to an intra-ruminal device comprising a body substantially impervious to rumen fluid, the body comprising a barrel, at least one outlet, at least one matrix comprising at least one active ingredient and at least one clay mineral, a compression arrangement and at least one variable geometry device dependent from the body, use of the intra-ruminal device and a method of treating a ruminant animal by administering the intra-ruminal device to the animal.