Reddy V Ranga, Rajmohan M Anantha, Shilpa R Laxmi, Raut Dilip M, Naveenkumar Kolla, Suryanarayana M V, Mathad Vijayavitthal T
Department of Analytical Research and Development, IPD, Dr. Reddy's Laboratories Ltd., Unit-III, Plot No. 116, S.V. Co-Op. Ind. Estate, Bollaram, Jinnaram, Medak Dist 502325, Andhra Pradesh, India.
J Pharm Biomed Anal. 2007 Apr 11;43(5):1836-41. doi: 10.1016/j.jpba.2006.12.006. Epub 2006 Dec 16.
To demonstrate the applicability of thermogravimetric analyzer as a tool for the quantification of pantaprazole sodium monohydrate in sesquihydrate, studies have been conducted. Thermal analysis (DSC, TGA) crystallographic (PXRD) and spectroscopic techniques (FT-IR) were used for the characterization of the polymorphs. Thermogravimetric analysis (TGA) analysis was explored by high-resolution dynamic (Hi-Res-dynamic) and high-resolution modulated (Hi-Res-modulated) test procedures to quantify the hydrate polymorphic mixtures. The two polymorphic forms exhibited significant differences and good resolution in the second derivative thermogram generated by Hi-Res-modulated test procedure. Thus, the TGA with Hi-Res-modulated test procedure was considered for the quantification of monohydrate in sesquihydrate. The calibration plot was constructed from the known mixtures of two polymorphs by plotting the peak area of the second derivative thermogram against the weight percent of monohydrate. Using this novel approach, 1 wt% limit of detection (LOD) was achieved. The polymorphic purity results, obtained by TGA in Hi-Res-modulated test procedure were found to be in good agreement with the results predicted by FT-IR and was comparable with the actual values of the known polymorphic mixtures. The Hi-Res-modulated TGA technique is very simple and easy to perform the analysis.
为了证明热重分析仪作为定量测定倍半水合物中泮托拉唑钠一水合物工具的适用性，已开展了相关研究。热分析（差示扫描量热法、热重分析法）、晶体学（粉末X射线衍射法）和光谱技术（傅里叶变换红外光谱法）被用于多晶型物的表征。通过高分辨率动态（高分辨动态）和高分辨率调制（高分辨调制）测试程序对热重分析（TGA）进行了探索，以定量水合物多晶型混合物。在高分辨调制测试程序生成的二阶导数热重曲线中，这两种多晶型形式表现出显著差异且分辨率良好。因此，采用高分辨调制测试程序的TGA被用于定量测定倍半水合物中的一水合物。通过绘制二阶导数热重曲线的峰面积与一水合物重量百分比的关系图，由两种多晶型物的已知混合物构建校准曲线。采用这种新方法，实现了1 wt%的检测限（LOD）。通过高分辨调制测试程序中的TGA获得的多晶型纯度结果与傅里叶变换红外光谱法预测的结果高度一致，且与已知多晶型混合物的实际值相当。高分辨调制TGA技术非常简单，易于进行分析。
