Abstract: | The stability of the experimental anti-tumour agent pancratistatin in human plasma has been investigated. A solid-phase extraction technique and an HPLC assay with external standards have been developed and validated. Extraction was performed using C18 cartridges and HPLC, analysis was performed on a 15 cm Hypersil BDS column using isocratic elution with 13% acetonitrile and aqueous solution of 1% (w/v) acetic acid. The lower limit of quantification for pancratistatin in 5% DMF–95% water was found to be 0.58 ng/ml (±10.58%) and 2.3 ng/ml (±9.2%) following extraction from human plasma. Mean recovery of 89.4% (±4.73%) was obtained over the concentration range 0.0023–9.45 μg/ml for a five day validation study. Pancratistatin was stable at room temperature in light or dark for at least 15 days, in the refrigerator at 4°C for at least 16 days and in the freezer at −20°C or −80°C for at least 28 days. Under all conditions monitored, % recovery of pancratistatin from human plasma was greater than 95% and no evidence of degradation had occurred. There also was no loss of pancratistatin after three cycles of freezing and thawing. |