Simultaneous estimation of paclitaxel and curcumin in nano-formulation: Stability analysis of drugs, optimization and validation of HPLC method

To find the therapeutic dose of paclitaxel with curcumin in nano-formulation, it is essential to study the stability of paclitaxel in presence of curcumin. The stability analysis of the drugs individually (paclitaxel/curcumin) and in combination (paclitaxel with curcumin) was carried out at different pH conditions (4.5 and 7.4 pH). Reverse Phase High Performance liquid chromatography method was developed for paclitaxel and curcumin in combined form and used to validate and analyze the amount of drug loaded in the Nano formulation. The method was optimized and developed using the design of experiments. The developed method was analyzed using C-18 Luna, 5 µm, 100Å, and 150 mm column using methanol and water with 0.05% of phosphoric acid as mobile phase (0.8 ml/minutes flow rate) and detected at a wavelength of 370 nm for curcumin and 227 nm for paclitaxel. Results showed that the paclitaxel's stability decreases rapidly in the presence of curcumin. The method was validated according to the International Conference on Harmonization guidelines and found to be reproducible with peaks showing good resolution with short retention time and can be used for simultaneous estimation of the amount of paclitaxel and curcumin loaded in nanoformulations.