粉末性製剤の安定性に関する研究 (第6報)

散剤中のビタミンB₁塩の吸湿による形態変化と安定度の関係

抄録

Examinations were made on the relationship between apparent change of various thiamine salts by absorption of humidity and stability of such salts in powders. Dihydrochloride, dinitrate, mononitrate, and naphthalenedisulfonate of thiamine were compounded with lactose, sucrose, or calcium pantothenate and the powders were maintained in a state of variety of humid conditions. Thiamine was then oxidized with gaseous cyanogen bromide and ammonia and the state of thiamine salt in the powder was observed by the resultant thiochrome fluorescence. When the thiamine salt retains the crystalline state in the powder, it is highly stable, while diffusion of thiamine into the powder by humidity absorption and resultant dissolution results in lowering of stability. In the powder compounded with calcium pantothenate, the mono-salt of thiamine, formed on absorption of humidity and subsequent neutralization, is insoluble in the case of thiamine dinitrate and remains stable without diffusion, but is unstable in the case of thiamine naphthalenedisulfonate by solution and diffusion.