広幅パルスNMRによる水和状態の新しい測定法と医薬品の凍結乾燥への応用

概要

論文の詳細を見る
An automatic recording system was developed for the dynamic measurement of the unfrozen water content and the spin-spin relaxation time as a continuous function of temperature. The system consists of a broad-line pulsed NMR spectrometer, a wave form memory apparatus, and a minicomputer, by using the special thermocouple shielded from electric noise by aluminum metal and coated with thermal insulater. The freezing and thawing processes were measured for aqueous solutions of saccharides and sugar alcohols, and the mobilities of solute and hydrated water molecules in frozen solutions were investigated. It was shown that sugar alcohol and mono- and oligosaccharide molecules are clustered by freezing of free and loosely-bound water and solidified in low temperature regions together with tightly-bound water. Mannitol is unusual amongst carbohydrates because that it crystallizes out in the thawing process, at about -22℃, and the freeze-drying of its aqueous solution is very easy. Hence mannitol is the most suitable dilient of drugs for freeze-drying use. But at the colling rate of one degree per minute or more slowly, it crystallizes out in the freezing process, and by freeze-drying powder which is unpractical in appearance and solubility with many spherulite crystals of about 1 mmφ was given. The advantages of the above method, namely the freezing curve method in pharmaceutical sciences were emphasized.
公益社団法人日本薬学会の論文
1981-08-25