Reversed-phase high-performance liquid chromatographic determination of verofylline in rat serum.

A simple and selective high-performance liquid chromatographic procedure has been developed for the determination of verofylline in rat serum. This assay procedure, which is suitable for the analysis of microsamples (0.05 or 0.1 ml serum), involves a single extraction followed by isocratic chromatography on an RP-18 analytical column with ultraviolet detection at 280 nm. The calibration curve is linear within the study range 0.25-75 micrograms/ml. The intra-day and inter-day coefficients of variation were below 5.7%. The specificity of the assay was confirmed by comparing the lipophilicity, absorbance, and chromatographic property of the apparent and authentic verofylline.