Determination of lycopene content in dietary supplements.

Lycopene, a highly conjugated carotenoid with strong antioxidant potential, is widely incorporated into nutraceutical formulations. However, its accurate quantification is often challenged by matrix interference and analytical variability. In this study, two analytical methods namely UV–Visible spectrophotometry and high-performance liquid chromatography (HPLC) method was developed and validated for the qualitative and quantitative estimation of lycopene in tablet and capsule formulations.
In the UV–Visible analysis of lycopene standard in n-hexane, showed a characteristic absorption maximum (λ max) value at 471 nm. The calibration curve over the concentration range of 2-10 PPM exhibited an excellent linearity (R² = 0.9991), confirming adherence to the Beer–Lambert law. On the other hand, chromatographic separation was performed using a reverse-phase C30 column (150 mm × 4.6 mm, 3 μm) using a mobile phase consisting of methanol: water (95:5, v/v) containing 5 mM ammonium acetate (phase A) and 100% MTBE (phase B). The mobile flow was gradient with a total run time of 35 min at flow rate of 1 mL/min. Detection was carried out at 471 nm. Lycopene was consistently eluted from column at a retention time of approximately 26 min, with no interference observed in blank chromatograms, confirming method specificity. Further, the method showed excellent linearity in the range of 0.5-10 PPM (R² ≥ 0.998). Accuracy assessed through recovery studies (using apocarotenal as internal standard) yielded recoveries between 84 and 126 %. Precision studies demonstrated %RSD values of 1.81, 1.89, and 1.39 at BSS, LOD, and LOQ levels, indicating good repeatability. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.5 PPM and 1 PPM, respectively. Overall, the validation results of an adopted HPLC method are %, in compliance with AOAC guidelines.
The validated method was successfully applied to six commercial samples (two tablets and four capsules). Tablet formulations exhibited higher lycopene content (543.95 -615.67 PPM), whereas capsule formulations showed comparatively lower concentrations (30.99 - 585.11 PPM). Overall, the developed method demonstrated high sensitivity, precision, and reliability which suggested that the suitability of method for routine quality control of lycopene in nutraceutical products.