<![CDATA[Background: Skin-whitening creams may contain undeclared or prohibited active ingredients, including hydroquinone, tretinoin, and resorcinol, which can pose health risks when used excessively or without medical supervision. A rapid simultaneous screening method is therefore important for routine quality control and market surveillance.Objective: This study aimed to develop and validate simultaneous analytical methods for determining the levels of hydroquinone, tretinoin, and resorcinol in cream preparations using a UV-Vis spectrophotometer.Methods: The wavelengths used in the UV-Vis spectrophotometric method for hydroquinone, tretinoin, and resorcinol were 294 nm, 339 nm, and 276 nm, respectively. The concentration ranges of the method were 5.0–40.0 µg/mL for hydroquinone and resorcinol, and 0.75–6.00 µg/mL for tretinoin. Validation included selectivity, linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Three pharmaceutical creams and three cosmetic creams obtained from an e-market were analyzed.Results: The method showed excellent linearity (R² = 0.9998–0.9999), recoveries of 99.15%–100.15%, and precision with %RSD below 2%. LOD values for hydroquinone, tretinoin, and resorcinol were 0.698, 0.078, and 0.740 µg/mL, respectively; corresponding LOQ values were 2.328, 0.261, and 2.466 µg/mL. Pharmaceutical cream results were consistent with label claims. Cosmetic cream A contained hydroquinone and tretinoin, whereas cosmetic creams B and C contained all three analytes. The measured concentrations reached 4.891% hydroquinone, 0.412% tretinoin, and 3.512% resorcinol.Conclusions: Sample A contains hydroquinone and resorcinol, while samples B and C contain hydroquinone, tretinoin, and resorcinol, respectively, with very high levels in all types of cosmetic cream samples.]]>
