A handheld NIR spectrophotometric method was developed, validated and applied for determination of tadalafil in tablets. The aim of our work was to develop analytical methods based on vibrational techniques and using low-cost portable equipment. Based on different chemometric modeling, we attempt to validate the method, that gave encouraging results from the principal component analysis (PCA), DD-SIMCA and PLS modeling. Then came optimization using an appropriate experiment plan. For validation, we used the total error approach with acceptance limits set at ±10% with a risk level of 5%. The method showed that it was possible to perform both qualitative and quantitative analysis of pharmaceutical products using low-cost portable NIR systems with chemometric tools. The developed approach enabled to cross the first step in implementing a NIR method for quality control of Tadalafil-based drugs in the DRC.
Validation difficulties of PLS method resulted from the lack of information about inter-days serial variations of spectral responses. This would be interesting to extend the study to a larger calibration interval in order to correct uncertainties that may result from the variability observed under different conditions, and to verify robustness. These are the limitations of this work, but the results are nevertheless very encouraging.