Chemical comparison of two dosage forms of Hemp Seed Pills by UHPLC-Q-ToF-MS/MS and multivariate statistical techniques

Hemp seed soft gel capsule (HSSGC) is a modernised dosage form that is derived from a traditional Chinese patent medicine, Hemp Seed Pills (HSP). Two dosage forms claim the same therapeutic effects; however, their chemical components and chemical equivalency are unclear. In the present study, an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry (UHPLC-ToF-MS)-based chemical profiling approach was proposed to rapidly evaluate the chemical differences between HSP and HSSGC as model dosage forms. Samples of the two dosage forms were subjected to UHPLC-ToF-MS analysis. The datasets of retention time (T_R) and mass-to-charge ratio (m/z) pairs, ion intensities and sample codes were processed with principal component analysis (PCA) and partial least squares discriminate analysis (PLS-DA) to holistically compare the difference between these two dosage form samples. A clear classification trend was observed in the score plot, and a loading bi-plot was generated in which the variables are correlated with the group and the samples that were observed. The important chemical components that caused differences among the samples were explored with a Variables Importance Projection (VIP) index. Using the proposed approach, global chemical differences were found between the two dosage forms and among samples of the same dosage form. The most important components that are related to the differences were identified and most of them were attributed to Fructus Aurantii Immaturus. It is suggested that this newly established approach could be used for pre-clinical trial chemical equivalence study or the quality evaluation of the traditional medicinal products with large variations in quality.