Using Attenuated Total Reflectance Fourier Transform Infrared Spectrometry, the current study aimed to develop and successively validate a simple, accurate method for simultaneous estimation of terbutaline sulphate, guaifenesin, and bromhexine hydrochloride in bulk, pharmaceutical preparation, or combination. Absorbance of the first derivative amplitude with a correlation coefficient (r) better than 0.99 was chosen for sample quantification after calibration models were established based on measurements of the three substances in their first derivative spectra zone at 4600-400 cm -1 Absorbance was determined at 1151cm -1 , 1332cm -1 , and 919 cm -1 for three compound respectively; after the spectra were transformed to first order derivative spectra (∆λ=1, scaling factor=10). This method was compared to the standard UV-visible spectrophotometry technique for quantitative sample analysis. The suggested technique shows promise as a quick screening tool due to a high correlation (r = 0.97) between the two approaches' predictions of content across samples. It was then shown that the installed method was suitable for determining the active ingredients in commercial and model cough syrup, with no interference from the formulation excipients being observed; these results suggested that this attenuated total Reflectance fourier transform Infrared could be used for the determination of the multiple active ingredients in their dosage form.