Development of a new analytical method for determination of acetylsalicylic and salicylic acids in tablets by reversed phase liquid chromatography

Abstract

Acetylsalicylic acid (AAS) is a drug utilized as analgesic, anti-inflammatory, and antipyretic medication, available worldwide and commonly used in Brazil. Salicylic acid (AS) is a precursor in AAS synthesis and is also produced during its degradation. The official United States Pharmacopoeia (USP) suggests the determination of these drugs by high performance liquid chromatography (HPLC), with ultraviolet detection, but this method has neither a high sensitivity (S AAS=0.12 mAbs/(μg/mL) and S AS=0.48 mAbs/(μg/mL)) nor resolution (Rs=1.61). The purpose of this study was to develop a new more adequate, accurate method by liquid phase chromatography than the current official methodology, and to use this new method in the determination of the tenors of acetylsalicylic, as of salicylic acids in tablets. The parameters of the chromatographic system for both the AAS and AS were satisfactory. Selectivity was verified by absorption spectra comparison in the ultraviolet (UV) range, during and after substance retention time. The linear range for AAS was 0.21 to 0.39 mg/mL, and that for AS was 6.3 to 11.7 μg/mL. The correlation coefficients (r) of the analytical curves of AAS and AS were 0.9995 and 0.9988, respectively; and the detection and quantification limits for the AS were 0.23 and 0.69 μg/mL. The sensitivity (S AAS=1.88 mAbs/(μg/mL) and S AS=1.84 mAbs/(μg/mL)) and the resolution (Rs =5.06) show the improvement obtained using this method over that described by the USP.