Abstract
Due to the potential toxicity of lenalidomide, a highly potent and severe life threatening human birth defect, a lot of precaution should to be taken in handling such kind of drugs.
Lenalidomide drug-excipient blend from the capsule pharmaceutical dosage form was subjected to different ICH prescribed stress conditions of thermal stress, pH hydrolysis, oxidation and photolysis. The drug was found to be stable only at photolysis and thermal stress, while it was extremely susceptible to other stressing conditions especially it showed extensive degradation under alkali conditions. For establishment of stability-indicating method, the rate of degradation in solutions in which different degradation products were formed were monitored at different time intervals, by using different concentrations of stressing reagents, and the separations was optimized by varying the LC conditions.
An acceptable separation was achieved through a multi-step gradient elution using an ACE® C18, 150 × 4.6 mm i.d, 3 μm, stainless steel analytical column and a mobile phase comprising of 0.01 M phosphate buffer (pH, 2.0 ± 0.1) as mobile phase-A, and a mixture of water and acetonitrile in the ratio of 200:800 (v/v) as mobile phase-B, with a flow rate and detection wavelength being 1.0 mL min−1 and 220 nm respectively. The major degradation products appeared at relative retention times (RRT) of 0.75, 0.86, 0.96, 1.33, 1.52, 1.99, 2.04, 2.62 and 2.66 respectively.
ACKNOWLEDGMENTS
The authors wish to thank the management of Dr. Reddy's group for supporting this work. We would also like to thank our colleagues, Professor's V. Suryanarayan Rao and L.K. Ravindranath for their constant encouragement and guidance.
Notes
Where, ND represent Not detected at that corresponding RRT and degradation condition.
αSpiked concentration.