Simultaneous liquid chromatographic determination of glutaric acid, phenylephrine, and benzyl alcohol in a prototype nasal spray with application to di- and tricarboxylic acids.

A rapid reversed-phase high-performance liquid chromatographic method for the simultaneous determination of glutaric acid, phenylephrine, and benzyl alcohol in nasal spray has been developed. UV detection was utilized at 210 nm for the assay of glutaric acid and phenylephrine with an adjustment to 254 nm for the measurement of benzyl alcohol. Linearity and recovery data were obtained for each component in spiked placebo studies. An investigation of the retention mechanisms of the three components showed that phenylephrine was retained by ion-pairing with octanesulfonate anion while glutaric acid and benzyl alcohol partitioned as a suppressed ion and a neutral molecule, respectively. The method has been further extended to the reversed-phase separation of di- and tricarboxylic acids using a totally aqueous 0.0074 M phosphoric acid mobile phase. The retention of these acids was related to their octanol-water partition coefficients and structural variation.