Determination of (4-chlorophenyl)thiomethylene bisphosphonic acid, a new bisphosphonate, in biological fluids by high-performance liquid chromatography.

A rapid and sensitive high-performance liquid chromatographic method for the assay of the bisphosphonate (4-chlorophenyl)thiomethylene bisphosphonic acid in plasma and urine is described. It requires selective precipitations and dissolutions of calcium salts prior to reversed-phase chromatography with UV detection. This method used semi-micro scale material and 200-microliters biological aliquots. The limit for accurate quantification is 50 ng/ml. Data on reliability criteria and application to a pharmacokinetic study are presented.