Development and Validation of a Stability-Indicating Method for Perillyl Alcohol Incorporated in Poly(lactide-co-glycolide) Nanoparticles and Stress Degradation Studies

Perillyl alcohol has been studied in the treatment of cancer disease. However, its high toxicity is a drawback, which can be overcome by its incorporation in nanostructured systems. The aim of this work was to develop and validate a chromatographic method for determination of perillyl alcohol encapsulation efficiency in a polymeric nanoparticles formulation and evaluation of the presence of related degradation products. Perillyl alcohol was subjected to forced conditions of hydrolysis (acidic, alkaline and neutral), oxidation, photolysis and thermal stress, as suggested in the International Conference of Harmonization (ICH) guidelines. The drug showed significant degradation under acidic conditions. The degradation products could be adequately separated on an XBridge C18 column (100 × 2.1 mm, 3.5 µm) using isocratic elution (350 µL min−1) of water/acetonitrile (65 : 35, v/v) at 210 nm. Data from validation studies demonstrated that the method is selective, linear (coefficient of determination (R2) > 0.999) over the range of 20.0-80.0 µg mL−1, precise (relative standard deviation (RSD) < 2.0%), accurate (98.07 to 101.99%) and robust for minor changes. The method was successfully applied to determine the encapsulation efficiency of perillyl alcohol in polymeric nanoparticles, both for product development and for quality control purposes. After nanoparticles production, the presence of degradation products was not observed indicating that the single-emulsion solvent-evaporation technique used does not favor chemical degradation of the drug.