Investigation of Water Mobility and Diffusivity in Hydrating Micronized Low-substituted Hydroxypropyl Cellulose, Hydroxypropylmethyl Cellulose, and Hydroxypropyl Cellulose Matrix Tablets by Magnetic Resonance Imaging (MRI)

概要

論文の詳細を見る
The water mobility and diffusivity in the gel-layer of hydrating low-substituted hydroxypropyl cellulose (LH41) tablets with or without a drug were investigated by magnetic resonance imaging (MRI) and compared with those properties in the gel-layer of hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC) tablets. For this purpose, a localized image-analysis method was newly developed, and the spin-spin relaxation time (T_2) and apparent self-diffusion coefficient (ADC) of water in the gel-layer were visualized in one-dimensional maps. Those maps showed that the extent of gel-layer growth in the tablets was in the order of HPC>HPMC≫LH41, and there was a water mobility gradient across the gel-layers of all three tablet formulations. The T_2 and ADC in the outer parts of the gel-layers were close to those of free water. In contrast, these values in the inner parts of the gel-layer decreased progressively; suggesting that the water mobility and diffusivity around the core interface were highly restricted. Furthermore, the correlation between the T_2 of ^1H proton in the gel-layer of the tablets and the drug release rate from the tablets was observed.
公益社団法人日本薬学会の論文
2002-12-01