Cao Xiaoping, Hancock Bruno C, Leyva Norma, Becker Jennifer, Yu Weili, Masterson Victoria M
Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA.
Int J Pharm. 2009 Feb 23;368(1-2):16-23. doi: 10.1016/j.ijpharm.2008.09.044. Epub 2008 Oct 7.
Refractive index is a basic physical property of pharmaceutical solids. In this paper, the refractive index values of 424 pharmaceutical solids from the literature were surveyed. It was found that the refractive index values exhibit a normal distribution with an overall mean value of 1.603. The Eisenlohr and Vogel methods developed for organic liquids were employed to estimate the refractive index for pharmaceutical solids. The estimated results were compared with experimentally measured values determined by polarized light microscopy. Both Eisenlohr and Vogel R(D) methods agreed very well with the measured mean refractive index values from the literature with an average absolute percent error of 1.22% and 1.25%, respectively. The evaluation for in-house measurements for Pfizer active pharmaceutical ingredients showed larger differences between the calculated and measured values. The results indicate that the Eisenlohr and Vogel R(D) methods can provide fast and accurate results for predicting the refractive index of pharmaceutical solids.
折射率是药物固体的一种基本物理性质。本文对文献中424种药物固体的折射率值进行了调查。结果发现，折射率值呈正态分布，总体平均值为1.603。采用为有机液体开发的艾森洛尔（Eisenlohr）法和沃格尔（Vogel）法来估算药物固体的折射率。将估算结果与偏光显微镜测定的实验测量值进行了比较。艾森洛尔法和沃格尔R(D)法与文献中测量的平均折射率值都非常吻合，平均绝对百分误差分别为1.22%和1.25%。对辉瑞活性药物成分的内部测量评估表明，计算值和测量值之间存在较大差异。结果表明，艾森洛尔法和沃格尔R(D)法可为预测药物固体的折射率提供快速准确的结果。
