Combination of piperaquine (PQ) (320mg) and dihydroartemisinin (DHA) (40 mg) is an anti-malarial formulation, which is recommended by World Health Organization (WHO). Simultaneous analysis of PQ and DHA can be problematic due to the lack of chromophores or fluorophores in DHA molecule. Whereas PQ possesses strong UV absorption and it presents in 8 times of DHA contents in the formulation. In this study, two spectroscopic methods, Fourier transform infrared (FTIR) and Raman spectroscopy, were developed for the determination of both drugs in combined tablets. The FTIR and Raman spectra were recorded in the attenuate total reflectance (ATR) and scattering modes, respectively. The original and pretreated spectra from FTIR and handheld-Raman were subjected to Unscrambler® program to construct partial least squares regression (PLSR) model comparing with references values obtained from high performance liquid chromatography (HPLC)-UV method. The optimal PLSR models of PQ and DHA from FTIR spectroscopy were obtained from orthogonal signal correction (OSC) pretreatment at the wavenumbers 400-1,800 cm-1 and 1,400-4,000 cm-1, respectively. For Raman spectroscopy of PQ and DHA, the optimal PLSR models were obtained from standard normal variate (SNV) pretreatment at the wavenumbers 1,200-2,300 cm-1 and OSC pretreatment at the wavenumber 400-2,300 cm-1, respectively. Determination of PQ and DHA in tablets from the optimum model was compared with HPLC-UV method. Results were not significantly different at 95% confidence limit (p-value >0.05). The chemometrics-assisted spectroscopic methods were fast (1-3 min), economical and less labor intensive. Moreover, the handheld Raman spectrometer is portable and can be utilized for onsite analysis to facilitate the detection of counterfeit or substandard drugs at ports of entry.

中文翻译：

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用于快速分析联合抗疟药片的化学计量学辅助光谱方法。

哌喹（PQ）（320毫克）和双氢青蒿素（DHA）（40毫克）的组合是世界卫生组织（WHO）推荐的抗疟疾制剂。由于 DHA 分子中缺乏发色团或荧光团，同时分析 PQ 和 DHA 可能会出现问题。而PQ具有很强的紫外线吸收能力，其在配方中的含量是DHA含量的8倍。在本研究中，开发了两种光谱方法，即傅里叶变换红外（FTIR）和拉曼光谱，用于测定组合片剂中的两种药物。FTIR 和拉曼光谱分别以衰减全反射 (ATR) 和散射模式记录。来自 FTIR 和手持式拉曼的原始和预处理光谱经过 Unscrambler® 程序构建偏最小二乘回归 (PLSR) 模型，与高效液相色谱 (HPLC)-UV 方法获得的参考值进行比较。FTIR 光谱中 PQ 和 DHA 的最佳 PLSR 模型分别通过波数 400-1,800 cm-1 和 1,400-4,000 cm-1 的正交信号校正 (OSC) 预处理获得。对于PQ和DHA的拉曼光谱，分别通过波数1,200-2,300 cm-1的标准正态变量（SNV）预处理和波数400-2,300 cm-1的OSC预处理获得最佳PLSR模型。将最佳模型测定片剂中 PQ 和 DHA 的含量与 HPLC-UV 法进行了比较。在 95% 置信限下，结果没有显着差异（p 值 >0.05）。化学计量学辅助光谱方法快速（1-3 分钟）、经济且劳动强度较低。此外，手持式拉曼光谱仪便于携带，可用于现场分析，方便在口岸检测假冒伪劣药品。