Simultaneous Determination of Guaifenesin, Salbutamol Sulfate or Dextromethorphan HBr and Guaifenesin Impurity (Guaiacol) by HPTLC Method.

Simple, selective and sensitive high-performance thin layer chromatographic (HPTLC) method has been developed and validated for the simultaneous determination of Guaifenesin (GUI) and its impurity Guaiacol (GUA), in two ternary mixtures with Salbutamol Sulfate (SAL) or Dextromethorphan HBr (DEX). The separation was carried out on HPTLC silica gel 60 F254using ethylacetate: hexane: methanol: ammonia (65:35:15:2, by volume) as a developing system followed by densitometric measurement of bands at 227 nm for the first mixture containing GUI, SAL, GUA and by using ethylacetate: hexane: methanol: ammonia (65:35:5:2, by volume) followed by densitometric measurement at 275 nm for the second mixture containing GUI, DEX, GUA. Calibration curves were constructed in the range of (0.2–4 μg/band), (0.2–2 μg/band) and (0.4–1.2 μg/band) with good correlation for GUI, SAL and GUA, respectively, for the first mixture and in the range of (0.4–2 μg/band), (0.2–2 μg/band) and (0.4–1.2 μg/band) with good correlation for GUI, DEX and GUA, respectively, for the second mixture. The developed method was validated according to ICH guidelines and demonstrated good accuracy and precision. The results were statistically compared to the reported methods with no significant difference, indicating the ability of our method to be used for routine analysis of drug product. [ABSTRACT FROM AUTHOR]