Patent ID: 8920818

Claim:
A coating on an oral pharmaceutical solid formulation comprising a pharmaceutically effective ingredient, the coating comprising polyvinyl alcohol, a swelling claim, and a sugar alcohol derivative-type surfactant which is at least one selected from the group consisting of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monooleate and sucrose stearate and optionally, a coloring and/or masking agent, the coating forming when coated on a solid formulation and dried, a coating film wherein the polyvinyl alcohol and the swelling clay occupy 64 to 94% mass percent of the coating film, and the coating having an oxygen permeability coefficient of less than 1×10 −4 cm 3 mm/cm 2 24 hr atm and a water vapor permeability of less than 1×10 −4 g mm/cm 2 24 hr atm, and in which laminated structures of said swelling clay are oriented planarly and dispersed in a network fashion.