Development and Validation of an Ion-Pair HPLC-UV Method for the Quantitation of Quinoline and Indoloquinoline Alkaloids in Herbal and Pharmaceutical Antimalarial Formulations

Figure 3

Analyses of contents in the herbal and pharmaceutical antimalarial formulations. (a) Content assays of quinine APIs (n = 3). Quinine contents (Ref: left y-axis) and related substances (Ref: right y-axis) detected. None of the APIs contained the right amount of quinine (indicated as the highlighted region in the graph) for product manufacture. (b) Contents of quinine (Ref: right y-axis) and its related alkaloidal substances (Ref: left y-axis) in the orthodox products. The highlighted region (Ref: right y-axis) indicates the range of contents deemed acceptable for quinine content. (c) Proportions of QBPAFs that either complied or did not comply with the acceptance criteria on quinine content. (d) Content assays of analytes in the herbal products. Quinine (Ref: left y-axis) and cryptolepine (Ref: right y-axis) constitute the main antimalarial alkaloids detected in the herbal products. Quinine (QUIN) and cryptolepine (CRPT) constitute the main APIs in the samples analyzed, while the related substances included cinchonidine (CCND), cinchonine (CCN), dihydroquinidine (DHQD), dihydroquinine (DHQN), and quinidine (QUND).

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