FTIR Method for Simultaneous determination of Captopril and Hydrochlorothiazid in Raw material and Pharmaceutical Dosage Form

A New FTIR method was developed and validated to simultaneous determination of Captopril (CAP) and Hydrochlorothiazid (HCTZ) in raw material and pharmaceutical dosage forms. The method includes preparation of solid pellets of hydrochlorothiazide and captopril using KBr and the quantitative determination peaks were chosen after conducting an excipient interference study. Then, the validation method was carried out according to the ICH guidelines. The calibration curve was developed using spectral region from 3115.92-3222.1 cm-1 for HCTZ and 1689.91-1800.73 cm-1 for CAP by plotted the peak height (intensity) for the selected peaks against the concentrations where, there are no overlapping with excipients used in the preparation of tablet dosage form. Captopril and Hydrochlorothiazid were detected in the following linear ranges: (0.4-2% w/w) and (0.4-2% w/w); respectively with excellent coefficeients of determination (R2), 0.9989 and 0.9982. Accuracy was found with excellent mean recovery values (98.0–102.0%). The precision showed RSD% was in a satisfactory range (< 2), evidencing the precision of the developed method. In Conclusion this method was inexpensive, environmental friendly and can be employed for simultaneous estimation of CAP and HCTZ in solid dosage forms.