QUANTITATIVE DETERMINATION OF ASPIRIN AND PARACETAMOL IN TABLETS

Okan ATAY*,o, Figen DINÇOL**

*Gazi University, Faculty of Pharmacy, Pharmacetucal Chemistry, 06330 Hipodrom, Ankara, TURKEY. **Refik Saydam Hygiene Institute Drug and Cosmetic Research Laboratory, Ankara, TURKEY.
oCorresponding Author

Summary:
Quantitative analysis of aspirin (ASP) and paracetamol (PA) containing tablets, which are widely used for analgesic-antipyretic purposes in this country, was carried out by employing various analytical methods in this study. Two different spectrophotometric, and a high pressure liquid chromatography (HPLC) methods have been proposed for this combination.
In the spectrophotometric absorbance ratio method, the maximum absorbance at 276 and 243 nm ASP+PA synthetic mixture in 0.1 N HCl were utilized and 231 nm was chosen as the isosbestic point. The absorbance ratios, 276/231 and 243/231, have been used in the regression analysis.
In the Vierordt method, A1(%1,1 cm) values of the two active principles have been determined at 276 and 243 nm in 1.1 N HCl, and the values of a = a2/a1 and b= ß2/ß1 were found by using A1 values. The a and b coefficients have been applied to the equation, which was developed by Vierordt.
In the high pressure liquid chromatography method, different working conditions from the monograph in USP XXII were applied and sodium benzoate was used as the internal standard.
For the quantitative determination, different regression equations were utilized for each method. In the absorbance ratio, Vierordt and HPLC methods, relative standard deviations were found as 0.89, 1, 1.4 % for ASP and 1.24, 1.39, 0.84 % for PA respectively.

Key words:
Aspirin, Paracetamol, Absorbance, Ratio, Vierordt, HPLC methods