Abstract: Incorporation of an aminosugar (e.g., glucosamine) to a preparation make a vitamin B1 stable. The content of the aminosugar is an effective amount to stabilize the vitamin B1, and is, for example, not less than 0.1 part by weight relative to 1 part by weight of the vitamin B1. Incorporation of the aminosugar can improve the disintegrativity of a solid preparation comprising a glycosaminoglycan (a hyaluronic acid, a chondroitin or a salt thereof). The content of aminosugars is not less than 0.1 part by weight relative to 1 part by weight of glycosaminoglycans. The solid preparation can inhibit forming gel masses of glycosaminoglycan and can improve the disintegrativity. Moreover, a joint disorder such as arthralgia can be improved by combination of the vitamin B1 and the glucosamine (e.g., glucosamine or a salt thereof).