Provided are: a novel additive which is for an orally disintegrating tablet and imparts rapid disintegratability and tablet hardness to the orally disintegrating tablet； and a method for producing the additive. An additive for an orally disintegrating tablet according to one embodiment of the present invention is characterized by comprising D-mannitol, low-substituted hydroxypropyl celluloses (excluding those in which the average particle size is 20 [mu]m or less and the degree of substitution of hydroxypropoxy groups is 11%, those in which the average particle size is 45 [mu]m or less and the degree of substitution of hydroxypropoxy groups is 14%, and those in which the average particle size is 45 [mu]m or less, the degree of substitution of hydroxypropoxy groups is 11%, and the particle diameter at 90% of the cumulative particle size distribution is 100 [mu]m or less), crospovidone, and crystalline cellulose.在此提供一種新穎的口腔內崩解錠用添加劑及其製造方法，此口腔內崩解錠用添加劑賦予口腔內崩解錠迅速的崩解性及錠劑硬度。本發明之一實施形態之口腔內崩解錠用添加劑係包含D-甘露醇、低取代度羥丙基纖維素(hydroxypropyl cellulose)、交聯聚乙烯吡咯烷酮(crospovidone)以及結晶纖維素而成，惟，前述低取代度羥丙基纖維素不包含平均粒徑為20μm以下且羥基丙氧(hydroxypropoxy)基的取代度為11%者、平均粒徑為45μm以下且羥基丙氧基的取代度為14%者以及平均粒徑為45μm以下且羥基丙氧基的取代度為11%且90%累積粒徑為100μm以下者。
