2017. AN ANALYTICAL STUDY FOR DEVELOPMENT AND VALIDATION OF METHOD FOR ESTIMATION OF TOTAL BENZALKONIUM CHLORIDE CONTENT AS A PRESERVATIVE IN AZELASTINE HYDROCHLORIDE PHARMACEUTICAL OPHTHALMIC FORMULATION BY REVERSE PHASE LIQUID CHROMATOGRAPHY APPROACH. International Journal of Pharmaceutical Sciences and Drug Research. 9, 5 (Sep. 2017), 268–274. DOI:https://doi.org/10.25004/IJPSDR.2017.090512.