VALIDATION AND QUANTITATIVE ANALYSIS OF CARMINE AND RHODAMINE B IN LIPSTICK FORMULATION

Objective: The objective of this study was to validate reversed phase-high performance liquid chromatography (RP-HPLC) method using photo-diode array detector for the simultaneous determination of carmine (CAR) and rhodamine B (RHO B) in lipstick products. Methods: CAR and RHO B were analysed using Cosmosil C18 column (250 mm x 4.6 mm i.d., 5 µm) using Shimadzu LC 20AD chromatograph equipped with photo-diode array (PDA) detector at 245-600 nm. The mobile phase used was acetonitrile-phosphate buffer pH 3.4 (5.5:4.5 v/v) delivered isocratically at flow rate of 1.0 ml/min, using column temperature at 35 °C. The optimized HPLC condition was validated by determining several characteristics including selectivity, linearity, sensitivity expressed by the limit of detection and limit of quantification, precision and accuracy. Results: The optimized HPLC condition could separate CAR and RHO B successfully with resolution value>2.0. The method was linear over studied concentration with a coefficient of determination (R2) 0.9999. The relative standard deviation (RSD) values were lower than those required RSD Horwitz and the recovery values were also acceptable, therefore, the developed method was precise and accurate. Conclusion: HPLC with PDA detector has been accurately and successfully used for quantitative analysis of CAR and RHO B. The developed method is simple and can be used for routine analysis of CAR and RHO B for quality assurance purposes