Development and Validation of a Stability‐Indicating HPLC‐UV Assay for Quantification of Tafenoquine Succinate in a Novel Paediatric Antimalarial Formulation

Tafenoquine, an 8‐aminoquinoline antimalarial, represents a promising advancement in combating malaria, but its bitter taste and lack of paediatric formulations hinder effective treatment for children. In response, we have formulated a chocolate‐based chewable tafenoquine tablet for paediatric use. A rapid, stability‐indicating high‐performance liquid chromatography method with ultraviolet detection was developed and validated for tafenoquine succinate quantification. Tablet samples were extracted with 85% methanol and analysed on a Waters XBridge C18 (150 × 4.6 mm, 5 μm) column using an isocratic mobile phase of 50 mM potassium dihydrogen orthophosphate buffer (pH 4.5) and acetonitrile (40:60, v/v). Detection was at 254 nm, with a retention time of 4.3 min. The method was linear over 0–313.6 μg/mL ( R 2 ≥ 0.999) with limits of detection and quantification of 2.22 and 6.73 μg/mL, respectively. Precision (RSD 0.15%–1.35%) and accuracy (101.48%–101.90%) met International Council for Harmonisation Q2 (R2) criteria. Forced degradation showed tafenoquine's susceptibility to acidic (29.33%), basic (18.83%), photolytic (complete degradation by day 14), and oxidative (8.33%) stress, with complete chromatographic separation from degradation products. This robust, rapid and low‐cost assay is suitable for routine content and stability testing, is adaptable to other tafenoquine formulations and can be further applied to clinical settings.