“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” (2017) International Journal of Pharmaceutical Sciences and Drug Research, 9(5), pp. 268–274. doi:10.25004/IJPSDR.2017.090512.