A Quality by Design (QbD) approach to the development of a gradient high-performance liquid chromatography for the simultaneous assay of curcuminoids and doxorubicin from long-circulating liposomes.

The present study highlights the advantages of using an Analytical Quality by Design (AQbD) approach to the optimization of a high-performance liquid chromatography method for the simultaneous assay of curcumin (CUR), demetoxycurcumin (DMC), bisdemetoxycurcumin (BDMC) and doxorubicin (DOX) co-encapsulated in long circulating liposomes. Within the QbD paradigm, the present study aimed to establish the method operable design region (MODR) for the optimization of the high-performance liquid chromatography-fluorescence (HPLC-FLD) assay by means of Design of Experiments (DOE) and response surface methodology, in order to achieve a good separation and quantification of all analyzed compounds along to an acceptable analysis time. A deep understanding of the quality target product profile (QTPP) and of the analytical target profile (ATP), followed by a risk assessment for variables that affect the efficiency of the method led to the development of a precise, accurate and cost-effective method. The assay was linear over the range of 2-20 µg/ml for all investigated compounds. The intra-and inter-day precision were less than 2%, with accuracies between 97-104% of the true values. The method was successfully applied to the quantification of curcuminoids and DOX from long-circulating liposomes.