Validation of high-performance liquid chromatography assay for quantification of formoterol in urine samples after inhalation using UV detection technique

J Chromatogr B Analyt Technol Biomed Life Sci. 2007 May 1;850(1-2):31-7. doi: 10.1016/j.jchromb.2006.10.059. Epub 2006 Nov 27.

Abstract

A novel high-performance liquid chromatography (HPLC) assay for the estimation of formoterol in urine samples was developed and validated. A solid phase extraction (SPE) using Oasis HLB was optimised to isolate formoterol from a urine matrix followed by HPLC with UV detection. This extraction procedure concentrated the final analyte forty times so that UV detection can be used to determine even a low concentration of formoterol in urine samples. The urinary assay was performed in accordance with FDA and ICH regulations for the validation of bioanalytical samples. The samples were injected onto a C18 Spherisorb (250 mm x 4.6 mm x 5 microm) analytical column maintained at 30 degrees C. The mobile phase consisted of 5 mM of potassium dihydrogen orthophosphate buffer (adjusted to pH 3 with ortho phosphoric acid):acetonitrile (ACN) (70:30, v/v), and the formoterol peak was detected at wavelength 214 nm. The extraction recovery of formoterol from the urine sample was >95%. The calibration curve was linear (r2=0.99) over formoterol concentrations ranging from 1.5 to 25 ng/mL (n=6). The method had an accuracy of >92% and intra and inter-day precision CV% of <3.9% and <2.2%, respectively, at three different concentrations low, medium and high (10, 15, 20 ng/mL). The limit of quantification (LOQ) for formoterol was found to be 1.50 ng/mL. The accuracy and precision at the LOQ level were 95% and %CV <3.7% (n=10), respectively. The method reported is simple, reliable, precise, and accurate and has the capacity to be used for determination of formoterol in urine samples.

Publication types

  • Validation Study

MeSH terms

  • Administration, Inhalation
  • Adrenergic beta-Antagonists / administration & dosage
  • Adrenergic beta-Antagonists / urine*
  • Chromatography, High Pressure Liquid / methods*
  • Ethanolamines / administration & dosage
  • Ethanolamines / urine*
  • Formoterol Fumarate
  • Humans
  • Reference Standards
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrophotometry, Ultraviolet / methods*

Substances

  • Adrenergic beta-Antagonists
  • Ethanolamines
  • Formoterol Fumarate