Polymorphic Transition Rate of Semisynthetic Fatty Suppository Bases

概要

論文の詳細を見る
The degree of polymorphic transition of semisynthetic fatty suppository bases was estimated by means of X-ray diffraction measurements. I_R values, defined as the relative intensities of two characteristic diffraction peaks of unstable A-form and stable B-form were useful for this purpose. Storage experiments using Witepsol H-15 suppositories containing 1% Brilliant Blue were performed. During storage, the changes of melting point, softening time and drug release rate were measured and compared with I_R. Each of these properties showed a correlation with I_R value irrespective of storage temperature or period. With lapse of time, the I_R values commonly fell to a minimum in the earlier period, subsequently increased to a maximum and then remained constant. This change depended markedly on the storage temperature, so we attempted to predict the I_R change using two rate parameters. One was the half-transition time t_<1/2> and the other was the shift factor A_r calculated by the reduced variable method. On plotting these rate parameters against 1/T, good linear relations were obtained, and the activation energies were 98 kcal and 108 kcal for t_<1/2> and A_r respectively. Using these values, prediction of the physical stability of the suppository seems to be possible. It was also shown that this I_R method is applicable to other commercial fatty vehicles.
社団法人日本薬学会の論文
1981-09-25