ABSTRACT
An assay employing automated solid-phase extraction (SPE) followed by high-performance liquid chromatography with positive ion TurboIonspray tandem mass spectrometry (LC-MS-MS) was developed and validated for the quantification of rosuvastatin (Crestor) in human plasma. Rosuvastatin is a hydroxy-methyl glutaryl coenzyme A reductase inhibitor currently under development by AstraZeneca. The standard curve range in human plasma was 0.1-30 ng/ml with a lower limit of quantification (LLOQ) verified at 0.1 ng/ml. Inaccuracy was less than 8% and imprecision less than +/-15% at all concentration levels. There was no interference from endogenous substances. The analyte was stable in human plasma following three freeze/thaw cycles and for up to 6 months following storage at both -20 and -70 degrees C. The assay was successfully applied to the analysis of rosuvastatin in human plasma samples derived from clinical trials, allowing the pharmacokinetics of the compound to be determined.
Subject(s)
Chromatography, Liquid/methods , Fluorobenzenes/blood , Hydroxymethylglutaryl-CoA Reductase Inhibitors/blood , Mass Spectrometry/methods , Pyrimidines , Sulfonamides , Humans , Reproducibility of Results , Rosuvastatin Calcium , Sensitivity and SpecificityABSTRACT
Over a 2-year period, the Orthopaedic Service at the Cincinnati (OH) Children's Hospital Medical Center noted eight patients to present with unusual fractures and musculoskeletal problems due to nutritional rickets. All were black, had been breast-fed until 6-12 months of age, and were vegetarians. Four were Black Hebrews who did not include any dairy products or vitamin D supplements in their diet. The diagnosis of nutritional rickets must still be considered when patients present with bone problems and the history reveals a dairy product-free diet.
