Stability of milrinone in 0.45% sodium chloride, 0.9% sodium chloride, or 5% dextrose injections.

The stability of milrinone in 0.45% and 0.9% sodium chloride injections and in 5% dextrose injection in glass and plastic containers was studied. Admixtures containing milrinone 0.2 mg/mL were prepared in three 500-mL glass containers, three 500-mL polyethylpolypropyl copolymer plastic containers, and three 1-L flexible plastic containers of each solution. Milrinone content was determined by high-performance liquid chromatography at intervals during 72 hours of storage at room temperature; one sample of each solution and container type was protected from light. Duplicate assays of each sample were performed, and samples were observed for visual and pH changes. In all samples milrinone concentrations were more than 97% of the initial concentration. No changes in pH or appearance occurred. Milrinone at a concentration of 0.2 mg/mL is stable for 72 hours at room temperature in 0.45% and 0.9% sodium chloride injections and in 5% dextrose injection in glass or plastic containers.

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.

Determination of 17-monochloroacetylajmaline and its metabolite in plasma by TLC fluorescence detection.

A sensitive and specific method is described for the determination of 17-monochloroacetylajmaline (I) and its metabolite, ajmaline (II), in plasma. Method specificity is accomplished by combining an ion-pair extraction with chromatography followed by development and utilization of reaction product fluorescence of the isolated species on silica gel. Recovery of I and II added to plasma or water averaged 70%. The major loss in the assay resulted during a solvent evaporation step and was reproducible over the concentration interval studied. The limit of detectability for I is 0.06 mu-g/2 ml of plasma. The method was used to determine plasma levels of I and II in the dog following a dose of 10 mg/kg iv of I.