A validated stability-indicating LC method for estimation of etoposide in bulk and optimized self-nano emulsifying formulation: Kinetics and stability effects

摘要

The present investigation was aimed to establish a validated stability-indicating liquid chromatographic method for the estimation of etoposide (ETP) in bulk drug and self-nano emulsifying formulation. ETP was successfully separated from the degradation products formed under stress conditions on LiChrospher 100 C"1"8 reverse-phase column (a 250mmx4.6mm i.d., 5-@mm particle size) using 55:45 (v/v) acetonitrile-phosphate buffer saline (pH 4.5) as the mobile phase, at a flow rate of 1.0mLmin^-^1 and detection at 283nm. The response was a linear function of analyte concentration (R^20.9997) over the concentration range of 0.05-50@mgmL^-^1. The method was validated for precision, accuracy, robustness, sensitivity and specificity. The % recovery of ETP at three different levels (50%, 100% and 150%) ranged between 93.84% and 100.06% in optimized self-nano emulsifying formulation, Etosid(R) soft-gelatin capsule and Fytosid(R) injection. First-order degradation kinetics of ETP were observed under acidic and alkaline conditions. The method was also applied for the stability assessment of self-nano emulsifying formulation under accelerated conditions, the formulation was found to be stable at all storage conditions with the shelf-life of 2.37years at 25^oC. The method holds promise for routine quality control of ETP in bulk, pharmaceutical formulations as well as in stability-indicating studies.