A validated stability-indicating HPLC method for simultaneous determination of Silymarin and Curcumin in various dosage forms

A new, reliable, sensitive and stability-indicating gradient HPLC method was introduced for the simultaneous determination of two anti-hepatotoxic polyphenolic drugs (Silymarin and Curcumin). The method was adapted to analyze both drugs in their dosage forms (tablets and capsules) with no interference from common excipients. The photo diode array detector was used as a tool for peak identification and purity confirmation especially that both drugs have several reported peaks. In order to assess the stability-indicating power of the assay procedure, SIL and CUR were subjected to different forced degradation studies: acidic, alkaline and neutral hydrolysis, photo-degradation, oxidative degradation and dry heat. The developed method could efficiently separate the parent drug peak from the degradation products peaks. The method was validated according to the ICH guidelines with respect to linearity, detection and quantitation limits, accuracy, precision, specificity, and robustness. Finally, the results of the proposed method for determination of SIL were statistically compared to the official BP method and no significant difference was found between them.