RP-HPLC method development and validation for simultaneous estimation of mesalamine and curcumin in bulk form as well as nanostructured lipid carriers

The aim of this study was to develop simple, advance, accurate and precise method for the quantification of mesalamine (Mes) and curcumin (Cur) in nanostructured lipid carriers (NLCs) by using high Performance Liquid Chromatography (HPLC) technique. The analysis of the method was done by using C-18 Nucleodur column with 250 mm x 4.6 mm dimensions and having i.d. of 5µ. The quantification of Mes and Cur on HPLC was done by using mobile phase acetonitrile and water in the different ratios at different time intervals (gradient method), flow rate kept 1 mL/min and wavelength was set up at isosbestic point 365 nm. By using gradient method of ACN and water the peak of Mes and Cur was found to be at 1.7 min and 9.6 min respectively. The developed method was validated in accordance with ICH Q2 (R1) guidelines. The developed method showed linearity in the range of 2-10 ppm with r² equals to 1 i.e 0.9998 for Mes and 0.9998 for Cur. The system suitability parameters of the method were also measured which were found to be tailing factor less than 2, resolution between Mes and Cur peaks was more than two and theoretical plates more than 2000. The LOD and LOQ of the developed method for Mes was found to be 0.14 µg/mL and 0.45 µg/mL. Whereas, LOD and LOQ of the developed method for Cur was found to be 0.17 µg/mL and 0.52 µg/mL respectively. The relative standard deviation of the developed method for both Mes and Cur were below 2 and percentage recovery was found to be between 95-105%. The robustness of the developed method was also checked by doing small changes in the flow rate and wavelength. The results of robustness study revealed that relative standard deviation and percentage recovery for both Mes and Cur were under acceptance criteria of ICH Q2 (R1) guidelines. This indicated that the method is precise, accurate, simple and robust. In addition, the developed method was effectively used for the estimation of entrapment efficiency (EE), drug loading (DL) and in vitro drug release study of Mes and Cur in the prepared Mes-Cur based NLCs. The EE of Mes and Cur in NLCs was found to be 99% and 84% respectively. Whereas, DL of Mes and Cur in the formulation was found to be 0.0019% and 0.0033% respectively. The in vitro drug release study showed that within 48h 100% Mes was released from NLCs. Whereas, 82.23% Cur was released from the NLCs.