Development and validation of HPTLC densitometric method for simultaneous determination of antazoline hydrochloride and tetryzoline hydrochloride in eye drop and its application as stability indicator

Abstract

A sensitive, selective, precise, accurate and stability indicating high-performance thin layer chromatographic (HPTLC)-densitometric method for analysis of antazoline hydrochloride and tetryzoline hydrochloride was developed. The method employed HPTLC aluminium plates precoated with silica gel 60 F254 as the stationary phase. The solvent system consisted of ethyl acetate: methanol: ammonia (10:10:1, v/v/v). Densitometric analysis of drugs was carried out in the absorbance mode at 216 nm. This system gave compact spots for both antazoline hydrochloride (Rf 0.60 ± 0.03) and tetryzoline hydrochloride (Rf 0.31 ± 0.03). Both drugs were subjected to stress test conditions like acid/alkali hydrolysis, oxidation by hydrogen peroxide, dry heat treatment and photo degradation. The spots for products of degradation were well resolved from the spots of respective intact drugs. The linear regression data for the calibration plots showed good linear relationship with r2 of 0.9979 and 0.9990 in the concentration range of 200-1800 ng/band for antazoline hydrochloride and 160-1440 ng/band for tetryzoline hydrochloride, respectively. The results indicated that the drugs are susceptible to degradation, to different extent under the different conditions.