紫外光谱法测定枸橼酸托法替布的解离常数
锦州医科大学, 药学系, 辽宁锦州 121001
| 摘 要： | 研究目的：解决了枸橼酸托法替布解离常数无确凿报道的问题，该文首次使用紫外光谱法不同解离常数模型算法通过实验测定了枸橼酸托法替布的解离常数，为药物分析和剂型设计提供重要参考。方法：用紫外光谱扫描不同枸橼酸托法替布pH梯度溶液，得到枸橼酸托法替布的的特征吸收波长，使用Adrien Albert推荐的光谱法中解离常数算法，根据分子态枸橼酸托法替布和离子化态枸橼酸托法替布的吸光度比值的对数值和pH的数据，计算出枸橼酸托法替布的解离常数。同时，根据选择不同参比波长和主特征吸收波长的吸光度比值与pH的关系曲线图推导出酸性环境下的电离突跃点，该突跃点即离子和分子态各一半的pH值对应值为解离常数。结果：得出枸橼酸托法替布在酸性条件下的解离常数为6.0。并且，使用商业化解离常数推算软件根据枸橼酸托法替布结构式推算出该物质pKa与实验结果接近，佐证了结果的准确性。配制相应的pH的缓冲液测试样品，分析结果情况良好。结论：使用紫外光谱法测定弱酸弱碱盐-枸橼酸托法替布的解离常数方法简单快捷，测定结果可信。 |
| 关 键 词： | 枸橼酸托法替布; 紫外光谱法; 解离常数; pKa |
| DOI： | 10.57237/j.cse.2024.01.003 |
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收稿日期: 2023-12-21
接受日期: 2024-01-24
在线出版日期: 2024-03-11
The Dissociation Constant of Tofacitinib Citrate Was Determined by Ultraviolet Spectroscopy
Department of Pharmacy, Jinzhou University, Jinzhou 121001, China
| Abstract: | Objective: In order to solve the problem that there is no conclusive report of the dissociation constant of tofacitinib citrate, the dissociation constant of tofacitinib citrate was determined for the first time by using the model algorithm of different dissociation constants of ultraviolet spectroscopy. It provides an important reference for the analysis and design of the drug form. Methods: The characteristic absorption wavelengths of tofacitinib citrate were obtained by scanning the pH gradient solutions of different tofacitinib citrate by ultraviolet spectroscopy, and the dissociation constant of tofacitinib citrate was calculated according to the logarithmic value of the absorbance ratio of the molecular tofacitinib citrate and the ionized tofacitinib citrate and the data of pH calculation. At the same time, the ionization hop in the acidic environment is derived according to the relationship between the absorbance ratio and pH of the selected different reference wavelengths and the main characteristic absorption wavelength, and the pH value of the ionic and molecular states is the dissociation constant. Results: The dissociation constant of tofacitinib citrate under acidic conditions was 6.0. In addition, the pKa of the substance was calculated according to the structural formula of tofacitinib citrate using commercial dissolution constant estimation software, which was close to the experimental results. The accuracy of the results is corroborated. Buffer test samples corresponding to pH were prepared, and the results were well analyzed. Conclusion: The method of determining the dissociation constant of weak acid and weak base salt - tofacitinib citrate by ultraviolet spectroscopy is simple and fast, and the determination results are reliable. |
| Keywords: | Tofacitinib Citrate; Ultraviolet Spectroscopy; Dissociation Constant; pKa |
基金
| 1. | 锦州医科大学大学生创新创业训练项目 (基金号: X202210160105) |
| 2. | 校级教改项目 (项目编号: 181231203035) |
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