HYDROGEL-CONTAINING ENVELOPES

摘要

An envelope having flexible water-permeable walls contains one or more water-disintegratable, self-coherent compresses of hydrogel particles. On contact with water, particularly in the stomach, the compresses first disintegrate and then the hydrogel particles swell to cause inflation of the envelope. The envelope is thereby inflated and retained in the stomach. The envelope is particularly useful as a device for the sustained release of active ingredient whereby the envelope contains biologically, veterinarily or pharmaceutically active ingredient in sustainedly releasable form. The use of the compressed hydrogel enables large amounts of active ingredient and/or hydrogel to be included in the envelope while still having an envelope sufficiently small to be swallowed by the patient or forced down the throat of an animal.