Simultaneous determination of rifampicin, isoniazid, pyrazinamide and ethambutol in 4-FDC tablet by Raman spectroscopy associated to chemometric approach

Tuberculosis is mainly treated by fixed dose combination therapy containing mainly rifampicin, isoniazid, pyrazinamide and ethambutol. The quality control of these drugs in these formulations is very important because of high incidence of resistance to these drugs. Most of the analytical methods developed for the quantification analyze these drugs individually and they are laborious, costly, and time consuming. The present work aims at developing an alternative analytical method addressing these limitations of the traditional methods A Raman spectroscopic method was developed to simultaneously estimate all these four first line antituberculosis drugs. This method has addressed all these limitations of traditional methods as it was very simple, rapid and cost effective. Calibration and validation samples of these drugs were prepared with a wider range and analyzed by both Raman and HPLC. Various figures of merit were determined for the developed method to evaluate the efficacy and quality of the method. Partial Least Squares regression (PLS) approach was used in Raman spectroscopic method to quantify the drugs. Correlation graphs and paired t test were used to compare these two analytical. Based on the results obtained, Raman spectroscopic method was found to be an efficient alternative for the simultaneous estimation of rifampicin, isoniazid, pyrazinamide and ethambutol. These results also indicate that the developed Raman method can be used as a screening technique in the quality control of fixed dose combination products for the therapy of tuberculosis.