Etoposide – inhalable fraction. Determination method in workplace air

Etoposide at room temperature is a fine white to yellow-brown crystalline odorless powder. Etoposide is one of the most widely used cytotoxic drugs and has strong antitumour activity in cases of small-cell lung cancer, testicular cancer or lymphoma. Occupational exposure to etoposide (mainly via skin contact or via inhalation route) may occur among group of healthcare workers or workers employed in the production of this drug. Exposure to etoposide can cause suppression of bone marrow function and gastrointestinal symptoms such as nausea, vomiting, bronchospasm, inflammation of mucous membranes, hair loss and secondary leukemia. Agency for Research on Cancer (IARC) has classified etoposide as a compound probably carcinogenic to humans (Group 2.A) and in combination with cisplatin and bleomycin as carcinogenic to humans (Group 1). The aim of this study was to develop and validate a sensitive method for determining inhalable fraction of etoposide concentrations in workplace air in the range from 1/10 to 2 MAC values, in accordance with the requirements of Standard PN-EN 482. The study was performed using a liquid chromatograph with tandem mass detection (HPLC-MS/MS). All chromatographic analysis were perfomed with Supelcosil LC 18 150 × 3 mm analytical column, which was eluted with a mixture of methanol and water with 0.1% of formic acid. This method is based on collecting inhalable fraction of etoposide on glass fiber filter, extracting with a mixture of methanol: water with addition of formic acid (0.1%), and chromatographic determining of resulted solution with HPLC-MS/MS technique. The average extraction efficiency of etoposide from filters was 90%. The method is linear (r = 0.9985) within the investigated working range from 0.036 μg/ml to 1.44 μg/ml. The calculated limit of detection (LOD) and the limit of quantification (LOQ) were 0.0086 and 0.0026 μg/ml, respectively. The analytical method described in this paper, thanks to HPLC MS/MS technique, enables specific and selective determination of inhalable fraction of etoposide in workplace air in the presence of other compounds at concentrations from 0.0001 mg/m3 (1/20 proposed MAC value). The method is precise, accurate and it meets the criteria for measuring chemical agents listed in Standard No. EN 482. The method can be used for assessing occupational exposure to etoposide and associated risk to workers’ health. The developed method of determining etoposide has been recorded as an analytical procedure (see appendix).