The two chromatographic methods have beendeveloped that are sensitive and validated for chlorpheniramine maleate (CM),guaifenesin (GF) and phenylephrine (PE) purpose of their combination and in presence of GF related substance guaiacol (GL) along with a preservative known as sodium benzoate (NaB).

The first method was created on thin layer chromatographic separation (TLC) and was followed by densitometric assessment of the separated spots. The separation was attained by using silica gel 60 F254TLC plates and ethyl acetate: methanol: toluene: ammonia (7:1.5:1:0.5, by volume) by means of a developing system. The densitometric quantification of the three drugs was done by the reflectance mode at 270 nm. The second method was carried with the use of high-performance liquid chromatography by diode array detection, by which the proposed components were separated on a reversed phase C18 analytical column by using phosphate buffer pH 2.9 (containing 0.1 gHeptane-1-sulphonic acid sodium salt) and acetonitrile (85:15, v/v) at 0.8mL/min for almost 4 minutes then 1 mL/min till end of the run by using flowrate swapping technique.

Both these methods were confirmed as per the International Council for Harmonization guidelines and has been successfully applied for the determination of chlorpheniramine maleate, phenylephrine, and guaifenesinin pure powder and also in combined cough syrup without any interference from the excipients.

Ref: Boltia SA, Soudi AT, Elzanfaly ES, Zaazaa HE. Simultaneous Quantification of Chlorpheniramine, Phenylephrine, Guaifenesin in Presence of Preservatives with Detection of Related Substance Guaiacol in their Cough Syrup by RP-HPLC and TLC-Densitometric Methods. J Chromatogr Sci. 2019 Jul1;57(6):552-559.