Prolonged-action multiple-layer tablets

Claim 1

A prolonged-action multiple-layer tablet having an increased rate of dissolution of the active ingredient from a given point of time onward, comprising an inert layer A made of an intimate mixture of a water-insoluble wax that has an average particle size of 10 μm or less and which is solid at ordinary temperatures, selected from the group consisting of hydrogenated castor oil, hydrogenated soybean oil, carnauba wax, paraffin, palmitic acid, stearic acid, bees wax, stearyl alcohol, and octadecyl alcohol, a disintegrator selected from the group consisting of low-substituted hydroxypropyl cellulose, carboxymethyl cellulose, calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, corn starch, sodium starch glycolate and hydroxypropyl starch, and a binder selected from the group consisting of hydroxypropyl cellulose, hydroxypropylmethyl cellulose, hydroxypropylmethyl cellulose phthalate, gelatin, α-starch, polyvinyl pyrrolidone and polyethylene glycol; and layer B made of an intimate mixture of a said water-insoluble wax that has an average particle size of 10 μm or less and which is solid at ordinary temperatures, a said disintegrator, a said binder and the active ingredient and wherein layer B covers part of layer A, and layer A covers part of layer B.