Simultaneous spectrophotometric analysis of codeine phosphate, acetylsalicylic acid, and caffeine in tablets by inverse least-squares and principal component regression techniques

Abstract

Inverse least-squares (ILS) and principal component regression (PCR) techniques were proposed for the spectrophotometric simultaneous analysis of ternary mixture containing codeine phosphate, acetylsalicylic acid and caffeine without any pretreatment. A training set of the title drugs was randomly prepared for both techniques. The absorbance values were measured at the 15 points in the wavelength range 220-290 nm for the absorption spectra. The ILS and PCR calibrations were constructed by using their algorithms and they were tested for the synthetic mixtures of three drugs. Means recoveries and relative standard deviations for ILS and PCR were found as 100.2 and 1.23%, 99.5 and 2.10% for codeine phosphate, 100.5 and 1.30%, 100.3 and 1.18% for acetylsalicylic acid and 99.4 and 1.33%, 99.3 and 1.31% for caffeine, respectively. We realised the numerical computations by using the 'Maple V' software. The results were successfully observed by applying the chemometric techniques to the tablets, and a good agreement was found between the obtained values and the indicated quantities of the pharmaceutical formulation marketed in Turkey.