Stability-indicating high-performance liquid chromatography of etoposide at various pH conditions using a reversed-phase octyl column.

A stability-indicating reversed-phase high-performance liquid chromatographic assay of etoposide is described. Baseline resolution was achieved with an octyl column for etoposide and its four degradation products, including picrolactone. Peak homogeneity of etoposide was confirmed by quantitating etoposide in degraded samples at 230, 254 and 286 nm, respectively. The assay was reproducible with low within-day and between-day variations. Application of the assay for stability kinetic study was demonstrated. Etoposide in 0.1 M hydrochloric acid (pH 1.29) degraded with a half-life of 2.85 h, which may be responsible for the low oral bioavailability of etoposide.