Aqua Conservans in nasal drops, can this be used?

Ciliotoxicity or methyl-and propyl-P-hydroxybenzoates: A dose-response and surface-response study. Jian L 1, Li Wan Po A . Abstract The effect of methyl-p-hydroxybenzoate (methyl paraben, MHB) and Propyl-P-hydroxybenzoate (propyl paraben, PHB) on Ciliary beat frequency was investigated using surface-response methodology. Both compounds are shown to be ciliotoxic at concentrations equal to or lower than those in use for Pres erving aqueous formulations. The dose-response curves show the typical sigmoidal pattern. Interaction by the two compounds is evidenced by the curved response surface for ciliotoxicity. You can best use isotone excipient for nasal drops a phosphate solution PH = 7  : NaH2PO4 0.22 G; Na2HPO4 0.36 G; NaCl 0.7 g; Benzalkonium chloride 0.01 g and water for injections up to 100 ml