The purpose of this study was to develop and validate a rapid and sensitive LC-MS/MS method for measuring Goserelin in human plasma (K2EDTA).
Goserelin is a synthetic analogue of a naturally occurring luteinising-hormone releasing hormone (LHRH). With its ability to suppress production of sex hormones, Goserelin is particularly used in treatment of breast and prostate cancer. For identification and quantification of Goserelin in biological matrices, a method has been reported in rabbit plasma with a lower limit of quantification (LLOQ) of 0.1 ng/mL and an overall run time of 10 minutes. Due to the low level dosage of Goserelin, the challenge of analyzing and quantifying Goserelin at an even lower concentration has to be addressed. In this study, a rapid and sensitive HPLC-MS/MS method was developed and validated for the determination of Goserelin at an LLOQ of 40 pg/mL in human plasma.
In order to remove the complex interferences in matrix and enrich the analyte of interest, Waters Oasis WCX µElution plate was used to extract Goserelin and internal standard from human plasma. The human plasma samples were spiked with Triptorelin as internal standard and extracted using solid phase extraction. The eluent was evaporated to dryness and the residue was reconstituted with acetonitrile:water:formic aicd (10:90:0.5). The analysis was conducted utilizing the Schimadzu Prominence 20AC HPLC system coupled with SRM detection in ESI positive mode on a Sciex API5500 mass spectrometer. Chromatographic separation was achieved using a reverse phase column with 0.1% formic acid in water and 0.1% formic acid in acetonitrile as the mobile phases. The peak of interest was well separated from interference peaks within a 4.0 minute run time.
Short-term Stability and Reproducibility
Short-term stability of Goserelin in human plasma was established for 4 freeze/thaw cycles at -70oC/room temperature and 25 hours at room temperature. Reinjection reproducibility of the extracted samples was demonstrated by reinjecting standards and quality control samples stored at 6oC for 48 hours.
- A rapid and sensitive HPLC-MS/MS method for the quantification of Goserelin in human plasma was developed.
- Solid Phase Extraction was successfully used in order to remove the complex interferences in matrix and enrich the analyte of interest.
- The method was validated as linear, accurate, precise and reproducible. It can be used to determine the concentration of Goserelin in human plasma as low as 0.04 ng/mL using only 100 µL of sample.
Meng Fang, Yinghe Li, Yifan Shi