Novel Stability-Indicating TLC-Densitometric Method for Quantification of Antazoline and Tetryzoline; Application to Pharmaceutical Formulation

Abstract

Ophthalmic pharmaceutical preparation containing antazoline hydrochloride (ANT) and tetryzoline hydrochloride (TET) is prescribed widely as an over the counter (OTC) medication to treatment allergic conjunctivitis and their determination in presence of their degradation products is a major challenge. A novel sensitive, selective, and precise thin-layer chromatographic method established to determination both ANT and TET in both bulk drugs, formulation, and in presence of their degradation products with the elucidation of degradate's structures. Upon using silica gel plates and means of a developing system using ethyl acetate: ethanol: ammonia (8: 2: 0.1, by volume) the studied drugs separation was achieved, and scanning was carried out at 220.0 nm for the separated bands with a 0.2–18.0 µg/band concentration range for each of ANT and TET. Optimum separation was achieved with values Rf of 0.42 and 0.69, for TET and ANT, respectively. Additionally, the studied drugs' stock solutions were imperiled to different stress conditions. Both drugs were found to be vulnerable to alkaline hydrolysis as well as oxidative degradation showing well resolved degradation products' peaks. While they held out against acidic, thermal and photo degradation. Mass spectrometry was employed to elucidate the degradates' structures. Validity was applied for the proposed method with respect to all validation parameters. Effectively the method was applied to estimate the cited drugs' in marketed ophthalmic formulation.

Keywords

• Antazoline
• Hydrolysis
• Mass spectrometry
• Oxidation
• Tetryzoline