Quality by design (QbD) based development and validation of RP-HPLC method for buserelin acetate in polymeric nanoparticles: Release study.

Buserelin acetate (BA) is the first gonadotropin hormone to reduce the level of estrogen for the treatment of breast cancer. In the present study, RP-HPLC study has been developed and validated subsequently using the analytical quality by design (AQbD) approach. Initially, an analytical target profile (ATP) was defined that outlined the performance of the established method. The risk identification and its assessment were performed using the Ishikawa fishbone diagram and risk assessment method (RAM) to identify critical method parameters (CMPs) having influence on critical analytical attributes (CAAs). The flow rate and pH of buffer were identified as CMPs and retention time (Rt) and peak area (Pa) were recognized as CAAs. The optimization of the method was determined by response surface methodology based on central composite design (CCD). The chromatographic separation was achieved by mobile phase (water: acetonitrile, 80:20 %, v/v) and pH was adjusted using orthophosphoric acid with Zorbax Eclipse plus C18 (4.6 mm × 150 mm × 5 μm) column. Elution was monitored at 220 nm using a photodiode array (PDA) detector. The calibration curve showed the linearity (regression coefficient, R = 0.9991) over the concentration range of 10-60 μg/mL. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.051 μg/mLand 0.254 μg/mL respectively. The method for analysis of BA was accurate using recovery ranging from 100.55 ± 0.93 to 103.45 ± 0.32 whereas the method was precise with % RSD for all parameters of chromatographic system was found to be not more than 1.0 %. Further, the method was robust based on intentionally changing the chromatographic conditions according to the recommended ICH Q2 (R1). Furthermore, poly D, L-lactic-co-glycolic (PLGA- Resomer RG505 and Resomer RG750) (50:50) based nanoparticles were prepared to encapsulate BA and understand the release of BA over the period of 48 h with Korsmeyer-Peppas release kinetics model. The stability of the stock solution was assessed over the 8th day and found to be stable for a longer duration of time. The method has been successfully applied for the analysis of BA in polymeric nanoparticles.