Quantification of active substances in some drugs using by derivative uv/vis spectroscopy

Abstract

UV/Vis spectroscopy is usually used in identification of active substances in drugs. The aim of this study was to test the application of the derivative UV/Vis spectroscopy in determination of the active substances content (ASC) in some drugs. Acetylsalicylic acid (ASA), meloxicam (M) and naproxen (N) were the selected ASC that were analyzed in different drug samples. The all analyses were carried out on the Perkin-Elmer Lambda 25 spectrophotometer in triplicate. The pure ASA, M and N were used as standards, and the calibration curve method was used to determine the ASC in the samples. The absorption spectrums were recorded in the visible (Vis) region 400–800 nm for ASA, and in ultraviolet (UV) 200–400 nm region for M and N. After recording the absorption spectrums, a third-order derivations were made using UV WinLab software. The obtained ASC was within acceptable limits with declared values (d.v.) for the two drugs: [meloxicam in Melox (Nobel), and naproxen in Nalgesin S (Krka)]. The observed deviations were <10% (the measured meloxicam content was 92.27%, and for naproxen was 90.06%) of the d.v., which is in line with the U.S. Pharmacopoeia (U.S.Ph.). In the case of Aspirin protect 100 (Bayer), the content of ASA was 89.56% of the d.v., which is slightly lower than that prescribed by the U.S.Ph. (deviation ±5% of the d.v.). Based on the obtained results, it can be concluded that UV/Vis derivative spectroscopy is a suitable method for determining of the ASC in some drugs.