Robust Regression Analysis of Full Overlapping Caffeine and Pyridoxine HCl UV-Vis Spectra in Pharmaceutical Tablet


  • Suprapto Suprapto Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
  • Yatim Lailun Ni'mah Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
  • Rifda Alifah Hisana Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia



UV-Vis Spectrophotometry, Robust regression, Caffeine, Pyridoxine HCl


The determination of caffeine and pyridoxine HCl in medicinal tablets has been successfully carried out. The mixture of caffeine and pyridoxine solution produces UV-Vis with full overlapping spectra. The full overlapping spectra can not be analyzed using conventional multicomponent analysis, as they do not have a distinct maximum wavelength. This research proposed a full overlapping spectra analysis using Robust regression. The regression models used in this research were based on Huber, RANSAC, and Theil-Sen Regression. Robust regression is a regression method that was not sensitive to the presence of outliers from the input or output data. Robust Regression models were trained using 25 standard solutions of caffeine and pyridoxine HCl at varied ratios. The models were validated using test solutions with known concentration ratios. The validated models were applied to determine the concentration of medicinal tablets. From this study, the recovery values of medicinal tablets obtained using Huber, RANSAC, and Theil-Sen Regression methods for caffeine were 96.94%, 97.19%, and 96.16% respectively, while the recoveries of pyridoxine HCl were 122.65%, 104.89%, and 107.48%.

Author Biography

Suprapto Suprapto, Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia



Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel, O., Blondelt, M., Prettenhofer, P., Weiss, R., Dubourg, V., Vanderplas, J., Passos, A., Cournapeau, D., Brucher, M., Perrot, M., and Duchesnay, E. (2011). Scikit-learn: Machine learning in python. Journal of Machine Learning Research. 12(85), 2825-2830.

Leacock, R. E., Stankus, J. J., and Davis, J. M. (2011). Simultaneous determination of caffeine and vitamin B6 in energy drinks by high-performance liquid chromatography (HPLC). J. Chem. Educ., 88(2), 232-234.

Ruxton, C. H. S. (2008). The impact of caffeine on mood, cognitive function, performance, and hydration: A review of benefits and risks. Nutrition Bulletin, 33(1), 15-25.

Bender, D. A. (1999). Non-nutritional uses of vitamin B6. Br J Nutr., 81(1), 7-20.

Yiğit, A., Yardım, Y., Çelebi, M., Levent, A., and Şentürk, Z. (2016). Graphene/Nafion composite film modified glassy carbon electrode for simultaneous determination of paracetamol, aspirin, and caffeine in pharmaceutical formulations. Talanta, 158, 21-29.

Chen, Q., Mou, S., Hou, X., and Ni, Z. (1998). Simultaneous determination of caffeine, theobromine, and theophylline in foods and pharmaceutical preparations by using ion chromatography. Analytica Chimica Acta, 371(2), 287-296.

Nugrahani, I., Manosa, E. Y., and Chintya, L. (2019). FTIR-derivative as a green method for simultaneous content determination of caffeine, paracetamol, and acetosal in a tablet compared to HPLC. Vibrational Spectroscopy, 104, 102941.

Martı́n, M. J., Pablos, F., and González, A. G. (1999). Simultaneous determination of caffeine and non-steroidal anti-inflammatory drugs in pharmaceutical formulations and blood plasma by reversed-phase HPLC from linear gradient elution. Talanta, 49(2), 453-459.

Dinç, E., Kökdil, G., and Onur, F. (2000). A comparison of matrix resolution method, ratio spectra derivative spectrophotometry and HPLC method for the determination of thiamine HCl and pyridoxine HCl in pharmaceutical preparation. Journal of Pharmaceutical and Biomedical Analysis, 22(6), 915-923.

Vaze, V. D. and Srivastava, A. K. (2008). Determination of pyridoxine hydrochloride in pharmaceutical preparations by calixarene based potentiometric sensor. Journal of Pharmaceutical and Biomedical Analysis, 47(1), 177-182.

Escandar, G. M., Bystol, A. J., and Campiglia, A. D. (2002). Spectrofluorimetric method for the determination of piroxicam and pyridoxine. Analytica Chimica Acta, 466(2), 275-283.

Qu, W., Wu, K., and Hu, S. (2004). Voltammetric determination of pyridoxine (Vitamin B6) by use of a chemically-modified glassy carbon electrode. Journal of Pharmaceutical and Biomedical Analysis, 36(3), 631-635.

Hernández, S. R., Ribero, G. G., and Goicoechea, H. C. (2003). Enhanced application of square wave voltammetry with glassy carbon electrode coupled to multivariate calibration tools for the determination of B6 and B12 vitamins in pharmaceutical preparations. Talanta, 61(5), 743-753.

Portela, J. G., Costa, A. C. S., and Teixeira, L. S. G. (2004). Determination of Vitamin B6 in pharmaceutical formulations by flow injection-solid phase spectrophotometry. Journal of Pharmaceutical and Biomedical Analysis, 34(3), 543-549.

Huopalahti R., and Sunell J. (1993). Use of capillary zone electrophoresis in the determination of B vitamins in pharmaceutical products, Journal of Chromatography A, 636(1), 133-135. Doi: 10.1016/0021-9673(93)80065-G.

McMaster, M. C. (1994). HPLC : a practical user’s guide / Marvin C. McMaster, Universitas Indonesia Library, 1994.

Kaflé, B. P. (2020). Chemical analysis and material characterization by spectrophotometry. Elsevier.

Lavagnini, I., Badocco, D., Pastore, P., and Magno, F. (2011). Theil–Sen nonparametric regression technique on univariate calibration, inverse regression, and detection limits. Talanta, 87, 180-188.

Aboul-Enein, H. Y., and Loutfy, M. A. (1984). Pyridoxine hydrochloride. Analytical Profiles of Drug Substances. Academic Press.

Atomssa T., and Gholap A. V. (2011). Characterization of caffeine and determination of caffeine in tea leaves using UV-visible spectrometer. African Journal of Pure and Applied Chemistry, 5(1), 1-8.

Chervenkov, H., and Slavov, K. (2019). Theil–Sen estimator vs. Ordinary least squares — Trend analysis for selected ETCCDI climate indices. Comptes rendus de l’Académie bulgare des sciences: sciences mathématiques et naturelles, 72, 47-54.

Rousseeuw, P. J., and Leroy, A. M. (1987). Robust regression and outlier detection. John Wiley & Sons.