Validated RP-HPLC-UV Method for the Quantitative Analysis and Stability Evaluation of Amoxicillin in Paediatric Gummy...

The development of products that encounter compliance from paediatric patients represents one of the challenges of pharmaceutical technology that aims to develop formulations able to overcome problems related to palatability and dosing flexibility and, in general, to patient acceptance. In this study, a fully validated reversed-phase high-performance liquid chromatography coupled with ultraviolet detection (RP-HPLC-UV) method was applied for the quantitative determination of amoxicillin (AMX) in an innovative gummy tablet formulation designed for paediatric use. The chromatographic method was optimized and validated largely (but not strictly) in accordance with ICH Q2(R1) guidelines, evaluating specificity, linearity, limit of quantification (LOQ), trueness, precision, robustness and ruggedness. A blank matrix derived from a blank formulation was employed to closely simulate the sample matrix during method validation and quantitative analysis. The method exhibited excellent linearity over the concentration range of 0.0039-0.25 mg/mL (R² = 0.99) with satisfactory trueness (recoveries between 101.3% and 102.4%) and high precision (coefficient of variation [CV] ≤ 1.6%). The LOQ was estimated between 0.0020 and 0.0039 mg/mL. Extraction recovery was also evaluated using penicillin G as a model compound due to its chemical and physicochemical similarity to AMX, yielding a recovery of 97.0% ± 0.1%. Application of the validated method to AMX-loaded gummy tablets confirmed a drug content of 94.7% ± 3.7% of the theoretical value. Stability studies, conducted over 6 months under different storage conditions, revealed a progressive decrease in AMX content within the gummy matrix with more pronounced degradation observed under vacuum at 25°C compared to storage in a dry cabinet at room temperature (RT). Overall, the developed RP-HPLC-UV method proved to be reliable and suitable for routine quality control and stability assessment of AMX-containing gummy tablets, supporting further development of this child-friendly dosage form.