BOX-BEHNKEN DESIGN ASSISTED ECO-FRIENDLY RP-HPLC-PDA METHOD FOR THE QUANTIFICATION OF PACLITAXEL: APPLICATION TO EVALUATE THE SOLUBILITY OF PACLITAXEL-CYCLODEXTRIN COMPLEX

Objective: Paclitaxel (PTX) is one of the oldest chemotherapeutic agents for cancer treatment. However, PTX is a class IV drug under the Biopharmaceutical Classification System (BCS), and its oral administration is restricted due to its low bioavailability. Complexing PTX with Beta-Cyclodextrin (β-CD) is an option to overcome the low solubility and bioavailability. This study aims to optimize and develop an RP-HPLC analytical method for quantifying PTX from the fabricated β-CD complex. Methods: The HPLC settings were optimized using Design-of-Experiments (DOE) software. The independent variables for the optimization process were buffer ratio, buffer pH, flow rate, and injection volume. The responses were Retention Time (RT), peak area, Tailing Factor (TF), and number of Theoretical Plates (TP) of PTX. The validated method was then used to measure the % entrapment from the PTX-β-CD complex. Results: The developed and optimized RP-HPLC method was validated as per International Council for Harmonisation (ICH) Q2 (R1) guidelines. The developed method showed linearity R2 = 0.999 with a 0.5-20 µg/ml range. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 95 and 125 ng/ml, respectively. The accuracy and precision for the developed method came under the acceptance criteria. The developed method was used to evaluate the enhancement of solubility of the prepared PTX-β-CD complex. The method was also used in the evaluation of % drug loading, % drug release and stability of the PTX-β-CD complex. The study clearly showed that the solubility of PTX increased from 0 to 1.14±0.53 µg/ml at pH 1.2 and 0 to 3.18±0.61 µg/ml at pH 6.8, respectively. The PTX-β-CD complex showed 73±3.75% drug release in 120 min at pH 1.2 and 87±3.51% at pH 6.8. The developed RP-HPLC method was found to be eco-friendly as per the Analytical Greenness (AGREE) metric approach and software analysis. Conclusion: An eco-friendly RP-HPLC analytical method was successfully developed and optimized for the quantification of PTX from the PTX-β-CD complex.