¹Pharmacochemistry, School of Pharmacy, Bandung Institute of Technology, Bandung, Indonesia
²The Drug and Food Monitoring Laboratory, Bandung, The Health Ministry of Republic Indonesia DOI : 10.35333/jrp.2020.228 This experiment aimed to develop and validate an analytical method using HPLC for phenylethyl resorcinol (PR) content determination in the emulsion-cream formula, consisted five preservative agents methylparaben, ethylparaben, propylparaben, butylparaben, and phenoxyethanol. Measurement was carried out with a UV detector and using a C18 column. Previously, a selectivity test was conducted to distinguish PR from the other whitening agents that were hydroquinone, alpha-arbutin, kojic acid, and vitamin C. The mobile phase system was optimized by using acetonitrile, water, and methanol, in a gradient concentration. The optimum condition was set in the flow rate of 1.0 mL/min, which provided a suitable chromatogram. Linearity in the range of 10.48-73.36 mg/mL showed a correlation coefficient (r) = 0.9999 and generated the detection and quantification limit of 0.7183 mg/L and 2.3943 mg/L, respectively. A robustness test was performed by a variate internal and external factor changes also proved the proper precision. Finally, the validated method was applied as an adequate quantitative analysis to determining phenyl ethyl resorcinol content in the whitening cream preparations. Keywords : Phenyl ethyl resorcinol; preservatives; whitening cream; HPLC; reverse phase; gradient mobile phase; validation method