Gad Asmaa G, Fayez Yasmin Mohammed, Kelani Khadiga M, Mahmoud Amr M
Analytical Chemistry Department, Faculty of Pharmacy, Modern University for Technology and Information Cairo Egypt.
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University El-Kasr El-Aini Street 11562 Cairo Egypt
RSC Adv. 2021 May 26;11(31):19196-19202. doi: 10.1039/d1ra01346g. eCollection 2021 May 24.
Thin layer chromatography (TLC) is a powerful and simple technique for screening and quantifying low quality and counterfeit pharmaceutical products. The detection methods used to detect and quantify separate analytes in TLC ranges from the densitometric method to mass spectrometric or Raman spectroscopic methods. This work describes the development and optimization of a simple and sensitive TLC method utilizing a smartphone CCD camera for verification of both identity and quantity of antibiotics in dosage form, namely ofloxacin and ornidazole. Mixtures of ofloxacin and ornidazole were chromatographed on a silica gel 60 F plate as a stationary phase. The optimized mobile phase is -butanol : methanol : ammonia (8 : 1 : 1.5 by volume). Iodine vapor has been used as a "universal stain" to visualize the spots on the TLC plates in order to obtain a visual image using the smartphone camera and a desk lamp as an illumination source, thus eliminating the need for a UV illumination source. The recorded images were processed to calculate the values ( values for ofloxacin and ornidazole were 0.12 and 0.76, respectively) which provide identity of the drugs while spot intensity was calculated using a commercially available smartphone app and employed for quantitative analysis of the antibiotics and "acetaminophen" as an example of a counterfeit substance. The smartphone TLC method yielded a linearity of ofloxacin and ornidazole in the range of 12.5-62.5 μg/band and 500-1000 μg/band, respectively. The limit of detection was found to be 1.6 μg/spot for ofloxacin and 97.8 μg/spot for ornidazole. The proposed method was compared with the bench top densitometric method for verification using a Camag TLC Scanner 3, the spot areas were scanned at 320 nm. The value of ofloxacin and ornidazole was calculated to be 0.12 and 0.76, respectively. The densitometric method yielded a linearity of ofloxacin and ornidazole in the range of 5-40 μg/band and 5-50 μg/band, respectively. The limit of detection was found to be 0.8 μg/spot for ofloxacin and 1.1 μg/spot for ornidazole. The proposed method has been successfully applied for the determination of ofloxacin and ornidazole present in more than one pharmaceutical dosage form and was comparable to the densitometric method.
薄层色谱法（TLC）是一种用于筛查和定量低质量及假冒药品的强大且简单的技术。用于在TLC中检测和定量分离分析物的检测方法范围从密度测定法到质谱法或拉曼光谱法。本工作描述了一种利用智能手机CCD相机开发和优化的简单且灵敏的TLC方法，用于验证剂型中抗生素（即氧氟沙星和奥硝唑）的身份和含量。氧氟沙星和奥硝唑的混合物在硅胶60 F板上作为固定相进行色谱分析。优化后的流动相为正丁醇∶甲醇∶氨水（体积比为8∶1∶1.5）。碘蒸气已被用作“通用显色剂”来使TLC板上的斑点显色，以便使用智能手机相机和台灯作为照明源获得视觉图像，从而无需紫外线照明源。对记录的图像进行处理以计算Rf值（氧氟沙星和奥硝唑的Rf值分别为0.12和0.76），该值可提供药物的身份信息，同时使用市售的智能手机应用程序计算斑点强度，并用于抗生素和作为假冒物质示例的“对乙酰氨基酚”的定量分析。智能手机TLC方法中氧氟沙星和奥硝唑的线性范围分别为12.5 - 62.5 μg/条带和500 - 1000 μg/条带。发现氧氟沙星的检测限为1.6 μg/斑点，奥硝唑的检测限为97.8 μg/斑点。将所提出的方法与使用Camag TLC Scanner 3进行验证的台式密度测定法进行比较，在320 nm处扫描斑点面积。计算得出氧氟沙星和奥硝唑的Rf值分别为0.12和0.76。密度测定法中氧氟沙星和奥硝唑的线性范围分别为5 - 40 μg/条带和5 - 50 μg/条带。发现氧氟沙星的检测限为0.8 μg/斑点，奥硝唑的检测限为1.1 μg/斑点。所提出的方法已成功应用于测定多种药物剂型中存在的氧氟沙星和奥硝唑，并且与密度测定法相当。
