Development and validation of a rp-hplc method for determination of chondroitin sulphate and curcumin in topical formulation

SUMMARY. A very simple, reproducible, accurate and precise method was developed for simultaneous determination of chondroitin sulphate (CS) and curcumin (Cur) using reverse phase High performance liquid chromatography (RP-HPLC) at 195nm in drug solutions and cream formulation. The chromatographic conditions for developed method were optimized by changing mobile phase compositions over different reverse phase columns. The developed method was validated by various parameters like specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), range, precision, accuracy and system suitability were performed and calculated. Stability studies under stressed conditions were carried out to evaluate the effects of acid, alkali, oxidation, heat and degradation by UV light. The validated method was found linear over the concentration range 192.05 to 1500μg/mL for CS and 2.9 to 1500 μg/mL for Cur, respectively, with a correlation coefficient (r² > 0.999) for both analytes. The inter-day and intra-day precision were found to be 1.80 and 0.72 for CS and Cur respectively. The accuracy calculated as recovery was between 95-105% for both CS and Cur. The stability studies showed that CS was highly sensitive to acid, base and oxidative degradation and to lesser extent to heat and UV, whereas no considerable effects of acid, heat and oxidation were observed in case of Cur, while curcumin shows a significant degradation under alkali and UV light exposure. In conclusion, the developed and validated method was found to be simple, precise, accurate and can be used for routine analysis of CS and Cur in drug solution and cream formulation.