Abstract: Masking particles which comprise a drug-containing particle containing a drug, an acid, and a carbonate, the drug-containing particle being coated with a coating layer containing a water-insoluble polymer sufficiently suppress drug release in the oral cavity and pharynx, rapidly release a drug after swallowing, and easily control the release suppression time of a drug. The acid may be at least one organic acid. The carbonate may be at least one water-soluble carbonate. Oral pharmaceutical compositions include tablets, granules, fine granules, powders.