Comparative study of reversed-phase high-performance liquid chromatography versus thin-layer chromatography-densitometry for determination of Citicoline sodium in presence of its alkaline degradation products

Abstract

Simple, sensitive, selective, and precise stability-indicating thin-layer chromatography (TLC)-densitometric and reversed-phase high-performance liquid chromatography (RP-HPLC) methods were developed and validated for the determination of citicoline sodium (CT) in the presence of its alkaline degradation products (CT Deg.) and in pharmaceutical oral solution. TLC-densitometry employs aluminum TLC plates precoated with silica gel 60 F254 as the stationary phase and ammonia-ethyl acetate-triethylamine (6:3.5:0.5, v/v) as the mobile phase to give compact spots for citicoline sodium (RF = 0.35) and its degradation product (RF = 0.1); the chromatogram was scanned at 272 nm. RP-HPLC utilizes a C18 column and a mobile phase consisting of methanol-water-acetic acid (60:40:0.1, v/v); the pH level was adjusted to 4 using 0.1% orthophosphoric acid, at a flow rate of 1 mL min−1 for the separation of citicoline sodium (tR = 1.801) and its degradation product (tR = 3.422). Quantitation was achieved by ultraviolet (UV) detection at 272 nm. Citicoline sodium was exposed to alkaline hydrolysis, and a comparative study was carried out to show the advantages of the proposed chromatographic methods in determination of citicoline sodium in the presence of its alkaline degradation products. The chromatographic methods were developed and validated as per the International Conference on Harmonization guidelines. As the methods could effectively separate the drug from their degradation products, these techniques can be employed as stability-indicating methods that have been successively applied to pharmaceutical formulations without interference from the excipients.