A STABILITY-INDICATING HPLC METHOD FOR THE DETERMINATION OF NAPHAZOLINE AND ITS DEGRADATION PRODUCT AND METHYL PARAHYDROXYBENZOATE IN PHARMACEUTICAL PREPARATIONS

A simple, rapid, selective, accurate and stability-indicating HPLC method for the simultaneous detn. of naphazoline and Me parahydroxybenzoate in pharmaceutical prepns. was developed and validated. The method employs a BDS Hypersil C18 column (5 μm; 150 × 4 mm), a mobile phase contg. methanol-0.05 M triethylamine plus 10% methanol pH 3 with o-phosphoric acid (30:70, vol./vol.), with a flow rate of 1 mL/min and detection at 254 nm. All the validation parameters (linearity, specificity, accuracy, repeatability, LOD/LOQ) were within the acceptance range and met the ICH Q2(R1) guideline. The stability indicating capability of this method has been demonstrated by sepg. degrdn. products as 1-naphthylacetylethylenediamine (impurity A) and 1-naphthylacetic acid (impurity B). Stability tests were performed under alk., acidic, neutral, and oxidizing conditions, and with simulated sunlight under standardised conditions in a suntest irradn. chamber. The proposed method was applied for routine quality control showing the obtained assay results for various marketed prepns. and for the inhouse formulation to be in good agreement with the declared amt. Compared with the pharmacopeial method much shorter retention times and a superior resolving capability have been shown. [on SciFinder(R)]